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annotate xml/en/docs/dev/development_guide.xml @ 1967:ef27e3ef0c46
The HTTP request redirection section of the development guide.
| author | Roman Arutyunyan <arut@nginx.com> |
|---|---|
| date | Wed, 19 Apr 2017 18:35:05 +0300 |
| parents | 9550ea66abdd |
| children | 69908bd68481 |
| rev | line source |
|---|---|
| 1899 | 1 <?xml version="1.0"?> |
| 2 | |
| 3 <!-- | |
| 4 Copyright (C) Nginx, Inc. | |
| 5 --> | |
| 6 | |
| 7 <!DOCTYPE article SYSTEM "../../../../dtd/article.dtd"> | |
| 8 | |
| 9 <article name="Development guide" | |
| 10 link="/en/docs/dev/development_guide.html" | |
| 11 lang="en" | |
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12 rev="2"> |
| 1899 | 13 |
| 14 <section name="Introduction" id="introduction"> | |
| 15 | |
| 16 | |
| 17 <section name="Code layout" id="code_layout"> | |
| 18 | |
| 19 <para> | |
| 20 <list type="bullet"> | |
| 21 <listitem> | |
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22 <literal>auto</literal> — build scripts |
| 1899 | 23 </listitem> |
| 24 | |
| 25 <listitem> | |
| 26 <literal>src</literal> | |
| 27 | |
| 28 <list type="bullet"> | |
| 29 | |
| 30 <listitem> | |
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31 <literal>core</literal> — basic types and functions — string, array, log, |
| 1899 | 32 pool etc |
| 33 </listitem> | |
| 34 | |
| 35 <listitem> | |
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36 <literal>event</literal> — event core |
| 1899 | 37 |
| 38 <list type="bullet"> | |
| 39 | |
| 40 <listitem> | |
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41 <literal>modules</literal> — event notification modules: epoll, kqueue, |
| 1899 | 42 select etc |
| 43 </listitem> | |
| 44 | |
| 45 </list> | |
| 46 | |
| 47 </listitem> | |
| 48 | |
| 49 <listitem> | |
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50 <literal>http</literal> — core HTTP module and common code |
| 1899 | 51 |
| 52 <list type="bullet"> | |
| 53 | |
| 54 <listitem> | |
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55 <literal>modules</literal> — other HTTP modules |
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56 </listitem> |
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57 |
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58 <listitem> |
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59 <literal>v2</literal> — HTTPv2 |
| 1899 | 60 </listitem> |
| 61 | |
| 62 </list> | |
| 63 | |
| 64 </listitem> | |
| 65 | |
| 66 <listitem> | |
|
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67 <literal>mail</literal> — mail modules |
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68 </listitem> |
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69 |
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70 <listitem> |
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71 <literal>os</literal> — platform-specific code |
| 1899 | 72 |
| 73 <list type="bullet"> | |
| 74 | |
| 75 <listitem> | |
| 76 <literal>unix</literal> | |
| 77 </listitem> | |
| 78 | |
| 79 <listitem> | |
| 80 <literal>win32</literal> | |
| 81 </listitem> | |
| 82 | |
| 83 </list> | |
| 84 | |
| 85 </listitem> | |
| 86 | |
| 87 <listitem> | |
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88 <literal>stream</literal> — stream modules |
| 1899 | 89 </listitem> |
| 90 | |
| 91 </list> | |
| 92 | |
| 93 </listitem> | |
| 94 | |
| 95 </list> | |
| 96 </para> | |
| 97 | |
| 98 </section> | |
| 99 | |
| 100 | |
| 101 <section name="Include files" id="include_files"> | |
| 102 | |
| 103 <para> | |
| 104 Each nginx file should start with including the following two files: | |
| 105 </para> | |
| 106 | |
| 107 | |
| 108 <programlisting> | |
| 109 #include <ngx_config.h> | |
| 110 #include <ngx_core.h> | |
| 111 </programlisting> | |
| 112 | |
| 113 <para> | |
| 114 In addition to that, HTTP code should include | |
| 115 </para> | |
| 116 | |
| 117 | |
| 118 <programlisting> | |
| 119 #include <ngx_http.h> | |
| 120 </programlisting> | |
| 121 | |
| 122 <para> | |
| 123 Mail code should include | |
| 124 </para> | |
| 125 | |
| 126 | |
| 127 <programlisting> | |
| 128 #include <ngx_mail.h> | |
| 129 </programlisting> | |
| 130 | |
| 131 <para> | |
| 132 Stream code should include | |
| 133 </para> | |
| 134 | |
| 135 | |
| 136 <programlisting> | |
| 137 #include <ngx_stream.h> | |
| 138 </programlisting> | |
| 139 | |
| 140 </section> | |
| 141 | |
| 142 | |
| 143 <section name="Integers" id="integers"> | |
| 144 | |
| 145 <para> | |
| 146 For general purpose, nginx code uses the following two integer types | |
| 147 <literal>ngx_int_t</literal> and <literal>ngx_uint_t</literal> which are | |
| 148 typedefs for <literal>intptr_t</literal> and <literal>uintptr_t</literal>. | |
| 149 </para> | |
| 150 | |
| 151 </section> | |
| 152 | |
| 153 | |
| 154 <section name="Common return codes" id="common_return_codes"> | |
| 155 | |
| 156 <para> | |
| 157 Most functions in nginx return the following codes: | |
| 158 </para> | |
| 159 | |
| 160 <para> | |
| 161 <list type="bullet"> | |
| 162 | |
| 163 <listitem> | |
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164 <literal>NGX_OK</literal> — operation succeeded |
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165 </listitem> |
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166 |
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167 <listitem> |
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168 <literal>NGX_ERROR</literal> — operation failed |
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169 </listitem> |
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170 |
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171 <listitem> |
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172 <literal>NGX_AGAIN</literal> — operation incomplete, function should be called |
| 1899 | 173 again |
| 174 </listitem> | |
| 175 | |
| 176 <listitem> | |
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177 <literal>NGX_DECLINED</literal> — operation rejected, for example, if disabled |
| 1899 | 178 in configuration. This is never an error |
| 179 </listitem> | |
| 180 | |
| 181 <listitem> | |
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182 <literal>NGX_BUSY</literal> — resource is not available |
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183 </listitem> |
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184 |
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185 <listitem> |
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186 <literal>NGX_DONE</literal> — operation done or continued elsewhere. |
| 1899 | 187 Also used as an alternative success code |
| 188 </listitem> | |
| 189 | |
| 190 <listitem> | |
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191 <literal>NGX_ABORT</literal> — function was aborted. |
| 1899 | 192 Also used as an alternative error code |
| 193 </listitem> | |
| 194 | |
| 195 </list> | |
| 196 </para> | |
| 197 | |
| 198 </section> | |
| 199 | |
| 200 | |
| 201 <section name="Error handling" id="error_handling"> | |
| 202 | |
| 203 <para> | |
| 204 For getting the last system error code, the <literal>ngx_errno</literal> macro | |
| 205 is available. | |
| 206 It's mapped to <literal>errno</literal> on POSIX platforms and to | |
| 207 <literal>GetLastError()</literal> call in Windows. | |
| 208 For getting the last socket error number, the | |
| 209 <literal>ngx_socket_errno</literal> macro is available. | |
| 210 It's mapped to <literal>errno</literal> on POSIX systems as well, | |
| 211 and to <literal>WSAGetLastError()</literal> call on Windows. | |
| 212 For performance reasons the values of <literal>ngx_errno</literal> or | |
| 213 <literal>ngx_socket_errno</literal> should not be accessed more than | |
| 214 once in a row. | |
| 215 The error value should be stored in a local variable of type | |
| 216 <literal>ngx_err_t</literal> for using multiple times, if required. | |
| 217 For setting errors, <literal>ngx_set_errno(errno)</literal> and | |
| 218 <literal>ngx_set_socket_errno(errno)</literal> macros are available. | |
| 219 </para> | |
| 220 | |
| 221 <para> | |
| 222 The values of <literal>ngx_errno</literal> or | |
| 223 <literal>ngx_socket_errno</literal> can be passed to logging functions | |
| 224 <literal>ngx_log_error()</literal> and <literal>ngx_log_debugX()</literal>, in | |
| 225 which case system error text is added to the log message. | |
| 226 </para> | |
| 227 | |
| 228 <para> | |
| 229 Example using <literal>ngx_errno</literal>: | |
| 230 </para> | |
| 231 | |
| 232 | |
| 233 <programlisting> | |
| 234 void | |
| 235 ngx_my_kill(ngx_pid_t pid, ngx_log_t *log, int signo) | |
| 236 { | |
| 237 ngx_err_t err; | |
| 238 | |
| 239 if (kill(pid, signo) == -1) { | |
| 240 err = ngx_errno; | |
| 241 | |
| 242 ngx_log_error(NGX_LOG_ALERT, log, err, "kill(%P, %d) failed", pid, signo); | |
| 243 | |
| 244 if (err == NGX_ESRCH) { | |
| 245 return 2; | |
| 246 } | |
| 247 | |
| 248 return 1; | |
| 249 } | |
| 250 | |
| 251 return 0; | |
| 252 } | |
| 253 </programlisting> | |
| 254 | |
| 255 </section> | |
| 256 | |
| 257 | |
| 258 </section> | |
| 259 | |
| 260 | |
| 261 <section name="Strings" id="strings"> | |
| 262 | |
| 263 | |
| 264 <section name="Overview" id="overview"> | |
| 265 | |
| 266 <para> | |
| 267 For C strings, nginx code uses unsigned character type pointer | |
| 268 <literal>u_char *</literal>. | |
| 269 </para> | |
| 270 | |
| 271 <para> | |
| 272 The nginx string type <literal>ngx_str_t</literal> is defined as follows: | |
| 273 </para> | |
| 274 | |
| 275 | |
| 276 <programlisting> | |
| 277 typedef struct { | |
| 278 size_t len; | |
| 279 u_char *data; | |
| 280 } ngx_str_t; | |
| 281 </programlisting> | |
| 282 | |
| 283 <para> | |
| 284 The <literal>len</literal> field holds the string length, | |
| 285 <literal>data</literal> holds the string data. | |
| 286 The string, held in <literal>ngx_str_t</literal>, may or may not be | |
| 287 null-terminated after the <literal>len</literal> bytes. | |
| 288 In most cases it’s not. | |
| 289 However, in certain parts of code (for example, when parsing configuration), | |
| 290 <literal>ngx_str_t</literal> objects are known to be null-terminated, and that | |
| 291 knowledge is used to simplify string comparison and makes it easier to pass | |
| 292 those strings to syscalls. | |
| 293 </para> | |
| 294 | |
| 295 <para> | |
| 296 A number of string operations are provided in nginx. | |
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297 They are declared in <path>src/core/ngx_string.h</path>. |
| 1899 | 298 Some of them are wrappers around standard C functions: |
| 299 </para> | |
| 300 | |
| 301 <para> | |
| 302 <list type="bullet"> | |
| 303 | |
| 304 <listitem> | |
| 305 <literal>ngx_strcmp()</literal> | |
| 306 </listitem> | |
| 307 | |
| 308 <listitem> | |
| 309 <literal>ngx_strncmp()</literal> | |
| 310 </listitem> | |
| 311 | |
| 312 <listitem> | |
| 313 <literal>ngx_strstr()</literal> | |
| 314 </listitem> | |
| 315 | |
| 316 <listitem> | |
| 317 <literal>ngx_strlen()</literal> | |
| 318 </listitem> | |
| 319 | |
| 320 <listitem> | |
| 321 <literal>ngx_strchr()</literal> | |
| 322 </listitem> | |
| 323 | |
| 324 <listitem> | |
| 325 <literal>ngx_memcmp()</literal> | |
| 326 </listitem> | |
| 327 | |
| 328 <listitem> | |
| 329 <literal>ngx_memset()</literal> | |
| 330 </listitem> | |
| 331 | |
| 332 <listitem> | |
| 333 <literal>ngx_memcpy()</literal> | |
| 334 </listitem> | |
| 335 | |
| 336 <listitem> | |
| 337 <literal>ngx_memmove()</literal> | |
| 338 </listitem> | |
| 339 | |
| 340 </list> | |
| 341 | |
| 342 </para> | |
| 343 | |
| 344 <para> | |
| 345 Some nginx-specific string functions: | |
| 346 </para> | |
| 347 | |
| 348 <para> | |
| 349 <list type="bullet"> | |
| 350 | |
| 351 <listitem> | |
| 352 <literal>ngx_memzero()</literal> fills memory with zeroes | |
| 353 </listitem> | |
| 354 | |
| 355 <listitem> | |
| 356 <literal>ngx_cpymem()</literal> does the same as | |
| 357 <literal>ngx_memcpy()</literal>, but returns the final destination address | |
| 358 This one is handy for appending multiple strings in a row | |
| 359 </listitem> | |
| 360 | |
| 361 <listitem> | |
| 362 <literal>ngx_movemem()</literal> does the same as | |
| 363 <literal>ngx_memmove()</literal>, but returns the final destination address. | |
| 364 </listitem> | |
| 365 | |
| 366 <listitem> | |
| 367 <literal>ngx_strlchr()</literal> searches for a character in a string, | |
| 368 delimited by two pointers | |
| 369 </listitem> | |
| 370 </list> | |
| 371 </para> | |
| 372 | |
| 373 <para> | |
| 374 Some case conversion and comparison functions: | |
| 375 </para> | |
| 376 | |
| 377 <para> | |
| 378 <list type="bullet"> | |
| 379 | |
| 380 <listitem> | |
| 381 <literal>ngx_tolower()</literal> | |
| 382 </listitem> | |
| 383 | |
| 384 <listitem> | |
| 385 <literal>ngx_toupper()</literal> | |
| 386 </listitem> | |
| 387 | |
| 388 <listitem> | |
| 389 <literal>ngx_strlow()</literal> | |
| 390 </listitem> | |
| 391 | |
| 392 <listitem> | |
| 393 <literal>ngx_strcasecmp()</literal> | |
| 394 </listitem> | |
| 395 | |
| 396 <listitem> | |
| 397 <literal>ngx_strncasecmp()</literal> | |
| 398 </listitem> | |
| 399 | |
| 400 </list> | |
| 401 </para> | |
| 402 | |
| 403 </section> | |
| 404 | |
| 405 | |
| 406 <section name="Formatting" id="formatting"> | |
| 407 | |
| 408 <para> | |
| 409 A number of formatting functions are provided by nginx. These functions support nginx-specific types: | |
| 410 </para> | |
| 411 | |
| 412 | |
| 413 <para> | |
| 414 <list type="bullet"> | |
| 415 | |
| 416 <listitem> | |
| 417 <literal>ngx_sprintf(buf, fmt, ...)</literal> | |
| 418 </listitem> | |
| 419 | |
| 420 <listitem> | |
| 421 <literal>ngx_snprintf(buf, max, fmt, ...)</literal> | |
| 422 </listitem> | |
| 423 | |
| 424 <listitem> | |
| 425 <literal>ngx_slrintf(buf, last, fmt, ...)</literal> | |
| 426 </listitem> | |
| 427 | |
| 428 <listitem> | |
| 429 <literal>ngx_vslprint(buf, last, fmt, args)</literal> | |
| 430 </listitem> | |
| 431 | |
| 432 <listitem> | |
| 433 <literal>ngx_vsnprint(buf, max, fmt, args)</literal> | |
| 434 </listitem> | |
| 435 | |
| 436 </list> | |
| 437 </para> | |
| 438 | |
| 439 <para> | |
| 440 The full list of formatting options, supported by these functions, can be found | |
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441 in <path>src/core/ngx_string.c</path>. Some of them are: |
| 1899 | 442 </para> |
| 443 | |
| 444 | |
| 445 <programlisting> | |
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446 %O — off_t |
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447 %T — time_t |
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448 %z — size_t |
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449 %i — ngx_int_t |
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450 %p — void * |
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451 %V — ngx_str_t * |
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452 %s — u_char * (null-terminated) |
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453 %*s — size_t + u_char * |
| 1899 | 454 </programlisting> |
| 455 | |
| 456 <para> | |
| 457 The ‘u’ modifier makes most types unsigned, ‘X’/‘x’ convert output to hex. | |
| 458 </para> | |
| 459 | |
| 460 <para> | |
| 461 Example: | |
| 462 | |
| 463 <programlisting> | |
| 464 u_char buf[NGX_INT_T_LEN]; | |
| 465 size_t len; | |
| 466 ngx_int_t n; | |
| 467 | |
| 468 /* set n here */ | |
| 469 | |
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470 len = ngx_sprintf(buf, "%ui", n) — buf; |
| 1899 | 471 </programlisting> |
| 472 | |
| 473 </para> | |
| 474 | |
| 475 </section> | |
| 476 | |
| 477 | |
| 478 <section name="Numeric conversion" id="numeric_conversion"> | |
| 479 | |
| 480 <para> | |
| 481 Several functions for numeric conversion are implemented in nginx: | |
| 482 </para> | |
| 483 | |
| 484 <para> | |
| 485 <list type="bullet"> | |
| 486 | |
| 487 <listitem> | |
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488 <literal>ngx_atoi(line, n)</literal> — converts a string of given length to a |
| 1899 | 489 positive integer of type <literal>ngx_int_t</literal>. |
| 490 Returns <literal>NGX_ERROR</literal> on error | |
| 491 </listitem> | |
| 492 | |
| 493 <listitem> | |
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494 <literal>ngx_atosz(line, n)</literal> — same for <literal>ssize_t</literal> |
| 1899 | 495 type |
| 496 </listitem> | |
| 497 | |
| 498 <listitem> | |
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499 <literal>ngx_atoof(line, n)</literal> — same for <literal>off_t</literal> |
| 1899 | 500 type |
| 501 </listitem> | |
| 502 | |
| 503 <listitem> | |
|
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504 <literal>ngx_atotm(line, n)</literal> — same for <literal>time_t</literal> |
| 1899 | 505 type |
| 506 </listitem> | |
| 507 | |
| 508 <listitem> | |
|
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509 <literal>ngx_atofp(line, n, point)</literal> — converts a fixed point floating |
| 1899 | 510 number of given length to a positive integer of type |
| 511 <literal>ngx_int_t</literal>. | |
| 512 The result is shifted left by <literal>points</literal> decimal | |
| 513 positions. The string representation of the number is expected to have no more | |
| 514 than <literal>points</literal> fractional digits. | |
| 515 Returns <literal>NGX_ERROR</literal> on error. For example, | |
| 516 <literal>ngx_atofp("10.5", 4, 2)</literal> returns <literal>1050</literal> | |
| 517 </listitem> | |
| 518 | |
| 519 <listitem> | |
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520 <literal>ngx_hextoi(line, n)</literal> — converts hexadecimal representation of |
| 1899 | 521 a positive integer to <literal>ngx_int_t</literal>. Returns |
| 522 <literal>NGX_ERROR</literal> on error | |
| 523 </listitem> | |
| 524 | |
| 525 </list> | |
| 526 </para> | |
| 527 | |
| 528 </section> | |
| 529 | |
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530 <section name="Regular expressions" id="regex"> |
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531 |
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532 <para> |
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533 The regular expressions interface in nginx is a wrapper around |
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534 the <link url="http://www.pcre.org">PCRE</link> |
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535 library. |
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536 The corresponding header file is <path>src/core/ngx_regex.h</path>. |
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537 </para> |
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538 |
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539 <para> |
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540 To use a regular expression for string matching, first, it needs to be |
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541 compiled, this is usually done at configuration phase. |
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542 Note that since PCRE support is optional, all code using the interface must |
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543 be protected by the surrounding <literal>NGX_PCRE</literal> macro: |
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544 <programlisting> |
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545 #if (NGX_PCRE) |
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546 ngx_regex_t *re; |
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547 ngx_regex_compile_t rc; |
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548 |
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549 u_char errstr[NGX_MAX_CONF_ERRSTR]; |
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550 |
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551 ngx_str_t value = ngx_string("message (\\d\\d\\d).*Codeword is '(?<cw>\\w+)'"); |
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552 |
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553 ngx_memzero(&rc, sizeof(ngx_regex_compile_t)); |
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554 |
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555 rc.pattern = value; |
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556 rc.pool = cf->pool; |
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557 rc.err.len = NGX_MAX_CONF_ERRSTR; |
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558 rc.err.data = errstr; |
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559 /* rc.options are passed as is to pcre_compile() */ |
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560 |
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561 if (ngx_regex_compile(&rc) != NGX_OK) { |
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562 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%V", &rc.err); |
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563 return NGX_CONF_ERROR; |
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564 } |
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565 |
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566 re = rc.regex; |
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567 #endif |
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568 </programlisting> |
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569 After successful compilation, <literal>ngx_regex_compile_t</literal> structure |
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570 fields <literal>captures</literal> and <literal>named_captures</literal> |
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571 are filled with count of all and named captures respectively found in the |
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572 regular expression. |
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573 </para> |
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574 |
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575 <para> |
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576 Later, the compiled regular expression may be used to match strings against it: |
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577 <programlisting> |
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578 ngx_int_t n; |
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579 int captures[(1 + rc.captures) * 3]; |
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580 |
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581 ngx_str_t input = ngx_string("This is message 123. Codeword is 'foobar'."); |
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582 |
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583 n = ngx_regex_exec(re, &input, captures, (1 + rc.captures) * 3); |
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584 if (n >= 0) { |
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585 /* string matches expression */ |
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586 |
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587 } else if (n == NGX_REGEX_NO_MATCHED) { |
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588 /* no match was found */ |
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589 |
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590 } else { |
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591 /* some error */ |
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592 ngx_log_error(NGX_LOG_ALERT, log, 0, ngx_regex_exec_n " failed: %i", n); |
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593 } |
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594 </programlisting> |
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595 The arguments of <literal>ngx_regex_exec()</literal> are: the compiled regular |
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596 expression <literal>re</literal>, string to match <literal>s</literal>, |
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597 optional array of integers to hold found <literal>captures</literal> |
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598 and its <literal>size</literal>. |
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599 The <literal>captures</literal> array size must be a multiple of three, |
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600 per requirements of the |
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601 <link url="http://www.pcre.org/original/doc/html/pcreapi.html">PCRE API</link>. |
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602 In the example, its size is calculated from a total number of captures plus |
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603 one for the matched string itself. |
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604 </para> |
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605 |
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606 <para> |
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607 Now, if there are matches, captures may be accessed: |
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608 <programlisting> |
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609 u_char *p; |
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610 size_t size; |
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611 ngx_str_t name, value; |
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612 |
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613 /* all captures */ |
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614 for (i = 0; i < n * 2; i += 2) { |
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615 value.data = input.data + captures[i]; |
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616 value.len = captures[i + 1] — captures[i]; |
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617 } |
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618 |
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619 /* accessing named captures */ |
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620 |
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621 size = rc.name_size; |
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622 p = rc.names; |
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623 |
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624 for (i = 0; i < rc.named_captures; i++, p += size) { |
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625 |
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626 /* capture name */ |
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627 name.data = &p[2]; |
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628 name.len = ngx_strlen(name.data); |
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629 |
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630 n = 2 * ((p[0] << 8) + p[1]); |
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631 |
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632 /* captured value */ |
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633 value.data = &input.data[captures[n]]; |
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634 value.len = captures[n + 1] — captures[n]; |
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635 } |
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636 </programlisting> |
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637 </para> |
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638 |
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639 <para> |
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640 The <literal>ngx_regex_exec_array()</literal> function accepts the array of |
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641 <literal>ngx_regex_elt_t</literal> elements (which are just compiled regular |
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642 expressions with associated names), a string to match and a log. |
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643 The function will apply expressions from the array to the string until |
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644 the match is found or no more expressions are left. |
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645 The return value is <literal>NGX_OK</literal> in case of match and |
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646 <literal>NGX_DECLINED</literal> otherwise, or <literal>NGX_ERROR</literal> |
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647 in case of error. |
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648 </para> |
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649 |
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650 </section> |
| 1899 | 651 |
| 652 </section> | |
| 653 | |
| 654 | |
| 655 <section name="Containers" id="containers"> | |
| 656 | |
| 657 | |
| 658 <section name="Array" id="array"> | |
| 659 | |
| 660 <para> | |
| 661 The nginx array type <literal>ngx_array_t</literal> is defined as follows | |
| 662 </para> | |
| 663 | |
| 664 | |
| 665 <programlisting> | |
| 666 typedef struct { | |
| 667 void *elts; | |
| 668 ngx_uint_t nelts; | |
| 669 size_t size; | |
| 670 ngx_uint_t nalloc; | |
| 671 ngx_pool_t *pool; | |
| 672 } ngx_array_t; | |
| 673 </programlisting> | |
| 674 | |
| 675 <para> | |
| 676 The elements of array are available through the <literal>elts</literal> field. | |
| 677 The number of elements is held in the <literal>nelts</literal> field. | |
| 678 The <literal>size</literal> field holds the size of a single element and is set | |
| 679 when initializing the array. | |
| 680 </para> | |
| 681 | |
| 682 <para> | |
| 683 An array can be created in a pool with the | |
| 684 <literal>ngx_array_create(pool, n, size)</literal> call. | |
| 685 An already allocated array object can be initialized with the | |
| 686 <literal>ngx_array_init(array, pool, n, size)</literal> call. | |
| 687 </para> | |
| 688 | |
| 689 | |
| 690 <programlisting> | |
| 691 ngx_array_t *a, b; | |
| 692 | |
| 693 /* create an array of strings with preallocated memory for 10 elements */ | |
| 694 a = ngx_array_create(pool, 10, sizeof(ngx_str_t)); | |
| 695 | |
| 696 /* initialize string array for 10 elements */ | |
| 697 ngx_array_init(&b, pool, 10, sizeof(ngx_str_t)); | |
| 698 </programlisting> | |
| 699 | |
| 700 <para> | |
| 701 Adding elements to array are done with the following functions: | |
| 702 </para> | |
| 703 | |
| 704 <para> | |
| 705 <list type="bullet"> | |
| 706 | |
| 707 <listitem> | |
| 708 <literal>ngx_array_push(a)</literal> adds one tail element and returns pointer | |
| 709 to it | |
| 710 </listitem> | |
| 711 | |
| 712 <listitem> | |
| 713 <literal>ngx_array_push_n(a, n)</literal> adds <literal>n</literal> tail elements | |
| 714 and returns pointer to the first one | |
| 715 </listitem> | |
| 716 | |
| 717 </list> | |
| 718 </para> | |
| 719 | |
| 720 <para> | |
| 721 If currently allocated memory is not enough for new elements, a new memory for | |
| 722 elements is allocated and existing elements are copied to that memory. | |
| 723 The new memory block is normally twice as large, as the existing one. | |
| 724 </para> | |
| 725 | |
| 726 | |
| 727 <programlisting> | |
| 728 s = ngx_array_push(a); | |
| 729 ss = ngx_array_push_n(&b, 3); | |
| 730 </programlisting> | |
| 731 | |
| 732 </section> | |
| 733 | |
| 734 | |
| 735 <section name="List" id="list"> | |
| 736 | |
| 737 <para> | |
| 738 List in nginx is a sequence of arrays, optimized for inserting a potentially | |
| 739 large number of items. The list type is defined as follows: | |
| 740 </para> | |
| 741 | |
| 742 | |
| 743 <programlisting> | |
| 744 typedef struct { | |
| 745 ngx_list_part_t *last; | |
| 746 ngx_list_part_t part; | |
| 747 size_t size; | |
| 748 ngx_uint_t nalloc; | |
| 749 ngx_pool_t *pool; | |
| 750 } ngx_list_t; | |
| 751 </programlisting> | |
| 752 | |
| 753 <para> | |
| 1958 | 754 The actual items are stored in list parts, defined as follows: |
| 1899 | 755 </para> |
| 756 | |
| 757 | |
| 758 <programlisting> | |
| 759 typedef struct ngx_list_part_s ngx_list_part_t; | |
| 760 | |
| 761 struct ngx_list_part_s { | |
| 762 void *elts; | |
| 763 ngx_uint_t nelts; | |
| 764 ngx_list_part_t *next; | |
| 765 }; | |
| 766 </programlisting> | |
| 767 | |
| 768 <para> | |
| 769 Initially, a list must be initialized by calling | |
| 770 <literal>ngx_list_init(list, pool, n, size)</literal> or created by calling | |
| 771 <literal>ngx_list_create(pool, n, size)</literal>. | |
| 772 Both functions receive the size of a single item and a number of items per list | |
| 773 part. | |
| 774 The <literal>ngx_list_push(list)</literal> function is used to add an item to the | |
| 775 list. Iterating over the items is done by direct accessing the list fields, as | |
| 776 seen in the example: | |
| 777 </para> | |
| 778 | |
| 779 | |
| 780 <programlisting> | |
| 781 ngx_str_t *v; | |
| 782 ngx_uint_t i; | |
| 783 ngx_list_t *list; | |
| 784 ngx_list_part_t *part; | |
| 785 | |
| 786 list = ngx_list_create(pool, 100, sizeof(ngx_str_t)); | |
| 787 if (list == NULL) { /* error */ } | |
| 788 | |
| 789 /* add items to the list */ | |
| 790 | |
| 791 v = ngx_list_push(list); | |
| 792 if (v == NULL) { /* error */ } | |
|
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793 ngx_str_set(v, "foo"); |
| 1899 | 794 |
| 795 v = ngx_list_push(list); | |
| 796 if (v == NULL) { /* error */ } | |
|
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797 ngx_str_set(v, "bar"); |
| 1899 | 798 |
| 799 /* iterate over the list */ | |
| 800 | |
| 801 part = &list->part; | |
| 802 v = part->elts; | |
| 803 | |
| 804 for (i = 0; /* void */; i++) { | |
| 805 | |
| 806 if (i >= part->nelts) { | |
| 807 if (part->next == NULL) { | |
| 808 break; | |
| 809 } | |
| 810 | |
| 811 part = part->next; | |
| 812 v = part->elts; | |
| 813 i = 0; | |
| 814 } | |
| 815 | |
| 816 ngx_do_smth(&v[i]); | |
| 817 } | |
| 818 </programlisting> | |
| 819 | |
| 820 <para> | |
| 821 The primary use for the list in nginx is HTTP input and output headers. | |
| 822 </para> | |
| 823 | |
| 824 <para> | |
| 825 The list does not support item removal. | |
| 826 However, when needed, items can internally be marked as missing without actual | |
| 827 removing from the list. | |
| 828 For example, HTTP output headers which are stored as | |
| 829 <literal>ngx_table_elt_t</literal> objects, are marked as missing by setting | |
| 830 the <literal>hash</literal> field of <literal>ngx_table_elt_t</literal> to | |
| 831 zero. Such items are explicitly skipped, when iterating over the headers. | |
| 832 </para> | |
| 833 | |
| 834 </section> | |
| 835 | |
| 836 | |
| 837 <section name="Queue" id="queue"> | |
| 838 | |
| 839 <para> | |
| 840 Queue in nginx is an intrusive doubly linked list, with each node defined as | |
| 841 follows: | |
| 842 </para> | |
| 843 | |
| 844 | |
| 845 <programlisting> | |
| 846 typedef struct ngx_queue_s ngx_queue_t; | |
| 847 | |
| 848 struct ngx_queue_s { | |
| 849 ngx_queue_t *prev; | |
| 850 ngx_queue_t *next; | |
| 851 }; | |
| 852 </programlisting> | |
| 853 | |
| 854 <para> | |
| 855 The head queue node is not linked with any data. Before using, the list head | |
| 856 should be initialized with <literal>ngx_queue_init(q)</literal> call. | |
| 857 Queues support the following operations: | |
| 858 </para> | |
| 859 | |
| 860 <para> | |
| 861 <list type="bullet"> | |
| 862 | |
| 863 <listitem> | |
| 864 <literal>ngx_queue_insert_head(h, x)</literal>, | |
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865 <literal>ngx_queue_insert_tail(h, x)</literal> — insert a new node |
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866 </listitem> |
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867 |
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868 <listitem> |
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869 <literal>ngx_queue_remove(x)</literal> — remove a queue node |
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870 </listitem> |
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871 |
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872 <listitem> |
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873 <literal>ngx_queue_split(h, q, n)</literal> — split a queue at a node, |
| 1899 | 874 queue tail is returned in a separate queue |
| 875 </listitem> | |
| 876 | |
| 877 <listitem> | |
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878 <literal>ngx_queue_add(h, n)</literal> — add second queue to the first queue |
| 1899 | 879 </listitem> |
| 880 | |
| 881 <listitem> | |
| 882 <literal>ngx_queue_head(h)</literal>, | |
|
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883 <literal>ngx_queue_last(h)</literal> — get first or last queue node |
| 1899 | 884 </listitem> |
| 885 | |
| 886 <listitem> | |
| 887 <literal>ngx_queue_sentinel(h)</literal> | |
| 888 - get a queue sentinel object to end iteration at | |
| 889 </listitem> | |
| 890 | |
| 891 <listitem> | |
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892 <literal>ngx_queue_data(q, type, link)</literal> — get reference to the beginning of a |
| 1899 | 893 queue node data structure, considering the queue field offset in it |
| 894 </listitem> | |
| 895 | |
| 896 </list> | |
| 897 </para> | |
| 898 | |
| 899 <para> | |
| 900 Example: | |
| 901 </para> | |
| 902 | |
| 903 | |
| 904 <programlisting> | |
| 905 typedef struct { | |
| 906 ngx_str_t value; | |
| 907 ngx_queue_t queue; | |
| 908 } ngx_foo_t; | |
| 909 | |
| 910 ngx_foo_t *f; | |
| 911 ngx_queue_t values; | |
| 912 | |
| 913 ngx_queue_init(&values); | |
| 914 | |
| 915 f = ngx_palloc(pool, sizeof(ngx_foo_t)); | |
| 916 if (f == NULL) { /* error */ } | |
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917 ngx_str_set(&f->value, "foo"); |
| 1899 | 918 |
| 919 ngx_queue_insert_tail(&values, f); | |
| 920 | |
| 921 /* insert more nodes here */ | |
| 922 | |
| 923 for (q = ngx_queue_head(&values); | |
| 924 q != ngx_queue_sentinel(&values); | |
| 925 q = ngx_queue_next(q)) | |
| 926 { | |
| 927 f = ngx_queue_data(q, ngx_foo_t, queue); | |
| 928 | |
| 929 ngx_do_smth(&f->value); | |
| 930 } | |
| 931 </programlisting> | |
| 932 | |
| 933 </section> | |
| 934 | |
| 935 | |
| 936 <section name="Red-Black tree" id="red_black_tree"> | |
| 937 | |
| 938 <para> | |
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939 The <path>src/core/ngx_rbtree.h</path> header file provides access to the |
| 1899 | 940 effective implementation of red-black trees. |
| 941 </para> | |
| 942 | |
| 943 | |
| 944 <programlisting> | |
| 945 typedef struct { | |
| 946 ngx_rbtree_t rbtree; | |
| 947 ngx_rbtree_node_t sentinel; | |
| 948 | |
| 949 /* custom per-tree data here */ | |
| 950 } my_tree_t; | |
| 951 | |
| 952 typedef struct { | |
| 953 ngx_rbtree_node_t rbnode; | |
| 954 | |
| 955 /* custom per-node data */ | |
| 956 foo_t val; | |
| 957 } my_node_t; | |
| 958 </programlisting> | |
| 959 | |
| 960 <para> | |
| 961 To deal with a tree as a whole, you need two nodes: root and sentinel. | |
| 962 Typically, they are added to some custom structure, thus allowing to | |
| 963 organize your data into a tree which leaves contain a link to or embed | |
| 964 your data. | |
| 965 </para> | |
| 966 | |
| 967 <para> | |
| 968 To initialize a tree: | |
| 969 </para> | |
| 970 | |
| 971 | |
| 972 <programlisting> | |
| 973 my_tree_t root; | |
| 974 | |
| 975 ngx_rbtree_init(&root.rbtree, &root.sentinel, insert_value_function); | |
| 976 </programlisting> | |
| 977 | |
| 978 <para> | |
| 979 The <literal>insert_value_function</literal> is a function that is | |
| 980 responsible for traversing the tree and inserting new values into correct | |
| 981 place. | |
| 982 For example, the <literal>ngx_str_rbtree_insert_value</literal> functions is | |
| 983 designed to deal with <literal>ngx_str_t</literal> type. | |
| 984 </para> | |
| 985 | |
| 986 | |
| 987 <programlisting> | |
| 988 void ngx_str_rbtree_insert_value(ngx_rbtree_node_t *temp, | |
| 989 ngx_rbtree_node_t *node, | |
| 990 ngx_rbtree_node_t *sentinel) | |
| 991 </programlisting> | |
| 992 | |
| 993 <para> | |
| 994 Its arguments are pointers to a root node of an insertion, newly created node | |
| 995 to be added, and a tree sentinel. | |
| 996 </para> | |
| 997 | |
| 998 <para> | |
| 999 The traversal is pretty straightforward and can be demonstrated with the | |
| 1000 following lookup function pattern: | |
| 1001 </para> | |
| 1002 | |
| 1003 | |
| 1004 <programlisting> | |
| 1005 my_node_t * | |
| 1006 my_rbtree_lookup(ngx_rbtree_t *rbtree, foo_t *val, uint32_t hash) | |
| 1007 { | |
| 1008 ngx_int_t rc; | |
| 1009 my_node_t *n; | |
| 1010 ngx_rbtree_node_t *node, *sentinel; | |
| 1011 | |
| 1012 node = rbtree->root; | |
| 1013 sentinel = rbtree->sentinel; | |
| 1014 | |
| 1015 while (node != sentinel) { | |
| 1016 | |
| 1017 n = (my_node_t *) node; | |
| 1018 | |
| 1019 if (hash != node->key) { | |
| 1020 node = (hash < node->key) ? node->left : node->right; | |
| 1021 continue; | |
| 1022 } | |
| 1023 | |
| 1024 rc = compare(val, node->val); | |
| 1025 | |
| 1026 if (rc < 0) { | |
| 1027 node = node->left; | |
| 1028 continue; | |
| 1029 } | |
| 1030 | |
| 1031 if (rc > 0) { | |
| 1032 node = node->right; | |
| 1033 continue; | |
| 1034 } | |
| 1035 | |
| 1036 return n; | |
| 1037 } | |
| 1038 | |
| 1039 return NULL; | |
| 1040 } | |
| 1041 </programlisting> | |
| 1042 | |
| 1043 <para> | |
| 1044 The <literal>compare()</literal> is a classic comparator function returning | |
| 1045 value less, equal or greater than zero. To speed up lookups and avoid comparing | |
| 1046 user objects that can be big, integer hash field is used. | |
| 1047 </para> | |
| 1048 | |
| 1049 <para> | |
| 1050 To add a node to a tree, allocate a new node, initialize it and call | |
| 1051 <literal>ngx_rbtree_insert()</literal>: | |
| 1052 </para> | |
| 1053 | |
| 1054 | |
| 1055 <programlisting> | |
| 1056 my_node_t *my_node; | |
| 1057 ngx_rbtree_node_t *node; | |
| 1058 | |
| 1059 my_node = ngx_palloc(...); | |
| 1060 init_custom_data(&my_node->val); | |
| 1061 | |
| 1062 node = &my_node->rbnode; | |
| 1063 node->key = create_key(my_node->val); | |
| 1064 | |
| 1065 ngx_rbtree_insert(&root->rbtree, node); | |
| 1066 </programlisting> | |
| 1067 | |
| 1068 <para> | |
| 1069 to remove a node: | |
| 1070 </para> | |
| 1071 | |
| 1072 | |
| 1073 <programlisting> | |
| 1074 ngx_rbtree_delete(&root->rbtree, node); | |
| 1075 </programlisting> | |
| 1076 | |
| 1077 </section> | |
| 1078 | |
|
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1079 <section name="Hash" id="hash"> |
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1080 |
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1081 <para> |
| 1920 | 1082 Hash table functions are declared in <path>src/core/ngx_hash.h</path>. |
|
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1083 Exact and wildcard matching is supported. |
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1084 The latter requires extra setup and is described in a separate section below. |
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1085 </para> |
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1086 |
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1087 <para> |
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1088 To initialize a hash, one needs to know the number of elements in advance, |
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1089 so that nginx can build the hash optimally. |
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1090 Two parameters that need to be configured are <literal>max_size</literal> |
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1091 and <literal>bucket_size</literal>. |
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1092 The details of setting up these are provided in a separate |
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1093 <link doc="../hash.xml">document</link>. |
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1094 Usually, these two parameters are configurable by user. |
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1095 Hash initialization settings are stored as the |
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1096 <literal>ngx_hash_init_t</literal> type, |
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1097 and the hash itself is <literal>ngx_hash_t</literal>: |
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1098 <programlisting> |
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1099 ngx_hash_t foo_hash; |
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1100 ngx_hash_init_t hash; |
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1101 |
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1102 hash.hash = &foo_hash; |
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1103 hash.key = ngx_hash_key; |
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1104 hash.max_size = 512; |
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1105 hash.bucket_size = ngx_align(64, ngx_cacheline_size); |
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1106 hash.name = "foo_hash"; |
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1107 hash.pool = cf->pool; |
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1108 hash.temp_pool = cf->temp_pool; |
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1109 </programlisting> |
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1110 The <literal>key</literal> is a pointer to a function that creates hash integer |
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1111 key from a string. |
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1112 Two generic functions are provided: |
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1113 <literal>ngx_hash_key(data, len)</literal> and |
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1114 <literal>ngx_hash_key_lc(data, len)</literal>. |
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1115 The latter converts a string to lowercase and thus requires the passed string to |
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1116 be writable. |
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1117 If this is not true, <literal>NGX_HASH_READONLY_KEY</literal> flag |
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1118 may be passed to the function, initializing array keys (see below). |
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1119 </para> |
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1120 |
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|
1121 <para> |
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1122 The hash keys are stored in <literal>ngx_hash_keys_arrays_t</literal> and |
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1123 are initialized with <literal>ngx_hash_keys_array_init(arr, type)</literal>: |
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1124 <programlisting> |
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1125 ngx_hash_keys_arrays_t foo_keys; |
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1126 |
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1127 foo_keys.pool = cf->pool; |
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1128 foo_keys.temp_pool = cf->temp_pool; |
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1129 |
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1130 ngx_hash_keys_array_init(&foo_keys, NGX_HASH_SMALL); |
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1131 </programlisting> |
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1132 The second parameter can be either <literal>NGX_HASH_SMALL</literal> or |
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1133 <literal>NGX_HASH_LARGE</literal> and controls the amount of preallocated |
|
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1134 resources for the hash. |
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|
1135 If you expect the hash to contain thousands elements, |
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1136 use <literal>NGX_HASH_LARGE</literal>. |
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1137 </para> |
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|
1138 |
|
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|
1139 <para> |
|
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1140 The <literal>ngx_hash_add_key(keys_array, key, value, flags)</literal> |
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1141 function is used to insert keys into hash keys array; |
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1142 <programlisting> |
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1143 ngx_str_t k1 = ngx_string("key1"); |
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1144 ngx_str_t k2 = ngx_string("key2"); |
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1145 |
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1146 ngx_hash_add_key(&foo_keys, &k1, &my_data_ptr_1, NGX_HASH_READONLY_KEY); |
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1147 ngx_hash_add_key(&foo_keys, &k2, &my_data_ptr_2, NGX_HASH_READONLY_KEY); |
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1148 </programlisting> |
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|
1149 </para> |
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|
1150 |
|
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|
1151 <para> |
|
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|
1152 Now, the hash table may be built using the call to |
|
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|
1153 <literal>ngx_hash_init(hinit, key_names, nelts)</literal>: |
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1154 |
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|
1155 <programlisting> |
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1156 ngx_hash_init(&hash, foo_keys.keys.elts, foo_keys.keys.nelts); |
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1157 </programlisting> |
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|
1158 |
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|
1159 This may fail, if <literal>max_size</literal> or <literal>bucket_size</literal> |
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1160 parameters are not big enough. |
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1161 When the hash is built, <literal>ngx_hash_find(hash, key, name, len)</literal> |
|
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1162 function may be used to look up elements: |
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|
1163 <programlisting> |
|
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1164 my_data_t *data; |
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1165 ngx_uint_t key; |
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1166 |
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1167 key = ngx_hash_key(k1.data, k1.len); |
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1168 |
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1169 data = ngx_hash_find(&foo_hash, key, k1.data, k1.len); |
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1170 if (data == NULL) { |
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1171 /* key not found */ |
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1172 } |
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1173 </programlisting> |
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|
1174 |
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1175 </para> |
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1176 |
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1177 <section name="Wildcard matching" id="wildcard_matching"> |
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1178 |
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1179 <para> |
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|
1180 To create a hash that works with wildcards, |
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1181 <literal>ngx_hash_combined_t</literal> type is used. |
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1182 It includes the hash type described above and has two additional keys arrays: |
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1183 <literal>dns_wc_head</literal> and <literal>dns_wc_tail</literal>. |
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1184 The initialization of basic properties is done similarly to a usual hash: |
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1185 <programlisting> |
|
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|
1186 ngx_hash_init_t hash |
|
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1187 ngx_hash_combined_t foo_hash; |
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1188 |
|
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1189 hash.hash = &foo_hash.hash; |
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1190 hash.key = ...; |
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1191 </programlisting> |
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1192 </para> |
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1193 |
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1194 <para> |
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1195 It is possible to add wildcard keys using the |
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1196 <literal>NGX_HASH_WILDCARD_KEY</literal> flag: |
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1197 <programlisting> |
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1198 /* k1 = ".example.org"; */ |
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1199 /* k2 = "foo.*"; */ |
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1200 ngx_hash_add_key(&foo_keys, &k1, &data1, NGX_HASH_WILDCARD_KEY); |
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1201 ngx_hash_add_key(&foo_keys, &k2, &data2, NGX_HASH_WILDCARD_KEY); |
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1202 </programlisting> |
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1203 The function recognizes wildcards and adds keys into corresponding arrays. |
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1204 Please refer to the |
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1205 <link doc="../http/ngx_http_map_module.xml" id="map"/> module |
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1206 documentation for the description of the wildcard syntax and |
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1207 matching algorithm. |
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1208 </para> |
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1209 |
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1210 <para> |
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1211 Depending on the contents of added keys, you may need to initialize up to three |
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1212 keys arrays: one for exact matching (described above), and two for matching |
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1213 starting from head or tail of a string: |
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1214 <programlisting> |
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1215 if (foo_keys.dns_wc_head.nelts) { |
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1216 |
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1217 ngx_qsort(foo_keys.dns_wc_head.elts, |
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1218 (size_t) foo_keys.dns_wc_head.nelts, |
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1219 sizeof(ngx_hash_key_t), |
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1220 cmp_dns_wildcards); |
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1221 |
|
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1222 hash.hash = NULL; |
|
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|
1223 hash.temp_pool = pool; |
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1224 |
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1225 if (ngx_hash_wildcard_init(&hash, foo_keys.dns_wc_head.elts, |
|
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1226 foo_keys.dns_wc_head.nelts) |
|
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|
1227 != NGX_OK) |
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|
1228 { |
|
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1229 return NGX_ERROR; |
|
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|
1230 } |
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1231 |
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1232 foo_hash.wc_head = (ngx_hash_wildcard_t *) hash.hash; |
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1233 } |
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1234 </programlisting> |
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1235 The keys array needs to be sorted, and initialization results must be added |
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1236 to the combined hash. |
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1237 The initialization of <literal>dns_wc_tail</literal> array is done similarly. |
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1238 </para> |
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|
1239 |
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1240 <para> |
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1241 The lookup in a combined hash is handled by the |
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1242 <literal>ngx_hash_find_combined(chash, key, name, len)</literal>: |
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1243 <programlisting> |
|
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1244 /* key = "bar.example.org"; — will match ".example.org" */ |
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1245 /* key = "foo.example.com"; — will match "foo.*" */ |
|
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1246 |
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1247 hkey = ngx_hash_key(key.data, key.len); |
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1248 res = ngx_hash_find_combined(&foo_hash, hkey, key.data, key.len); |
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1249 </programlisting> |
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1250 </para> |
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1251 |
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1252 </section> |
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1253 |
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1254 </section> |
| 1899 | 1255 |
| 1256 </section> | |
| 1257 | |
| 1258 | |
| 1259 <section name="Memory management" id="memory_management"> | |
| 1260 | |
| 1261 | |
| 1262 <section name="Heap" id="heap"> | |
| 1263 | |
| 1264 <para> | |
| 1265 To allocate memory from system heap, the following functions are provided by | |
| 1266 nginx: | |
| 1267 </para> | |
| 1268 | |
| 1269 <para> | |
| 1270 <list type="bullet"> | |
| 1271 | |
| 1272 <listitem> | |
|
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1273 <literal>ngx_alloc(size, log)</literal> — allocate memory from system heap. |
| 1899 | 1274 This is a wrapper around <literal>malloc()</literal> with logging support. |
| 1275 Allocation error and debugging information is logged to <literal>log</literal> | |
| 1276 </listitem> | |
| 1277 | |
| 1278 <listitem> | |
|
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1279 <literal>ngx_calloc(size, log)</literal> — same as |
| 1899 | 1280 <literal>ngx_alloc()</literal>, but memory is filled with zeroes after |
| 1281 allocation | |
| 1282 </listitem> | |
| 1283 | |
| 1284 <listitem> | |
|
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1285 <literal>ngx_memalign(alignment, size, log)</literal> — allocate aligned memory |
| 1899 | 1286 from system heap. This is a wrapper around <literal>posix_memalign()</literal> |
| 1287 on those platforms which provide it. | |
| 1288 Otherwise implementation falls back to <literal>ngx_alloc()</literal> which | |
| 1289 provides maximum alignment | |
| 1290 </listitem> | |
| 1291 | |
| 1292 <listitem> | |
|
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1293 <literal>ngx_free(p)</literal> — free allocated memory. |
| 1899 | 1294 This is a wrapper around <literal>free()</literal> |
| 1295 </listitem> | |
| 1296 | |
| 1297 </list> | |
| 1298 </para> | |
| 1299 | |
| 1300 </section> | |
| 1301 | |
| 1302 | |
| 1303 <section name="Pool" id="pool"> | |
| 1304 | |
| 1305 <para> | |
| 1306 Most nginx allocations are done in pools. Memory allocated in an nginx pool is | |
| 1307 freed automatically when the pool in destroyed. This provides good | |
| 1308 allocation performance and makes memory control easy. | |
| 1309 </para> | |
| 1310 | |
| 1311 <para> | |
| 1312 A pool internally allocates objects in continuous blocks of memory. Once a | |
| 1313 block is full, a new one is allocated and added to the pool memory | |
| 1314 block list. When a large allocation is requested which does not fit into | |
| 1315 a block, such allocation is forwarded to the system allocator and the | |
| 1316 returned pointer is stored in the pool for further deallocation. | |
| 1317 </para> | |
| 1318 | |
| 1319 <para> | |
| 1320 Nginx pool has the type <literal>ngx_pool_t</literal>. | |
| 1321 The following operations are supported: | |
| 1322 </para> | |
| 1323 | |
| 1324 <para> | |
| 1325 <list type="bullet"> | |
| 1326 | |
| 1327 <listitem> | |
|
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1328 <literal>ngx_create_pool(size, log)</literal> — create a pool with given |
| 1899 | 1329 block size. The pool object returned is allocated in the pool as well. |
| 1330 </listitem> | |
| 1331 | |
| 1332 <listitem> | |
|
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1333 <literal>ngx_destroy_pool(pool)</literal> — free all pool memory, including |
| 1899 | 1334 the pool object itself. |
| 1335 </listitem> | |
| 1336 | |
| 1337 <listitem> | |
|
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1338 <literal>ngx_palloc(pool, size)</literal> — allocate aligned memory from pool |
|
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1339 </listitem> |
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1340 |
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1341 <listitem> |
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1342 <literal>ngx_pcalloc(pool, size)</literal> — allocated aligned memory |
| 1899 | 1343 from pool and fill it with zeroes |
| 1344 </listitem> | |
| 1345 | |
| 1346 <listitem> | |
|
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1347 <literal>ngx_pnalloc(pool, size)</literal> — allocate unaligned memory from pool. |
| 1899 | 1348 Mostly used for allocating strings |
| 1349 </listitem> | |
| 1350 | |
| 1351 <listitem> | |
|
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1352 <literal>ngx_pfree(pool, p)</literal> — free memory, previously allocated |
| 1899 | 1353 in the pool. |
| 1354 Only allocations, forwarded to the system allocator, can be freed. | |
| 1355 </listitem> | |
| 1356 | |
| 1357 </list> | |
| 1358 </para> | |
| 1359 | |
| 1360 <programlisting> | |
| 1361 u_char *p; | |
| 1362 ngx_str_t *s; | |
| 1363 ngx_pool_t *pool; | |
| 1364 | |
| 1365 pool = ngx_create_pool(1024, log); | |
| 1366 if (pool == NULL) { /* error */ } | |
| 1367 | |
| 1368 s = ngx_palloc(pool, sizeof(ngx_str_t)); | |
| 1369 if (s == NULL) { /* error */ } | |
|
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1370 ngx_str_set(s, "foo"); |
| 1899 | 1371 |
| 1372 p = ngx_pnalloc(pool, 3); | |
| 1373 if (p == NULL) { /* error */ } | |
|
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1374 ngx_memcpy(p, "foo", 3); |
| 1899 | 1375 </programlisting> |
| 1376 | |
| 1377 <para> | |
| 1378 Since chain links <literal>ngx_chain_t</literal> are actively used in nginx, | |
| 1379 nginx pool provides a way to reuse them. | |
| 1380 The <literal>chain</literal> field of <literal>ngx_pool_t</literal> keeps a | |
| 1381 list of previously allocated links ready for reuse. For efficient allocation of | |
| 1382 a chain link in a pool, the function | |
| 1383 <literal>ngx_alloc_chain_link(pool)</literal> should be used. | |
| 1384 This function looks up a free chain link in the pool list and only if it's | |
| 1385 empty allocates a new one. To free a link <literal>ngx_free_chain(pool, cl)</literal> | |
| 1386 should be called. | |
| 1387 </para> | |
| 1388 | |
| 1389 <para> | |
| 1390 Cleanup handlers can be registered in a pool. | |
| 1391 Cleanup handler is a callback with an argument which is called when pool is | |
| 1392 destroyed. | |
| 1393 Pool is usually tied with a specific nginx object (like HTTP request) and | |
| 1394 destroyed in the end of that object’s lifetime, releasing the object itself. | |
| 1902 | 1395 Registering a pool cleanup is a convenient way to release resources, close file |
| 1899 | 1396 descriptors or make final adjustments to shared data, associated with the main |
| 1397 object. | |
| 1398 </para> | |
| 1399 | |
| 1400 <para> | |
| 1401 A pool cleanup is registered by calling <literal>ngx_pool_cleanup_add(pool, | |
| 1402 size)</literal> which returns <literal>ngx_pool_cleanup_t</literal> pointer to | |
| 1403 be filled by the caller. The <literal>size</literal> argument allows allocating | |
| 1404 context for the cleanup handler. | |
| 1405 </para> | |
| 1406 | |
| 1407 | |
| 1408 <programlisting> | |
| 1409 ngx_pool_cleanup_t *cln; | |
| 1410 | |
| 1411 cln = ngx_pool_cleanup_add(pool, 0); | |
| 1412 if (cln == NULL) { /* error */ } | |
| 1413 | |
| 1414 cln->handler = ngx_my_cleanup; | |
|
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1415 cln->data = "foo"; |
| 1899 | 1416 |
| 1417 ... | |
| 1418 | |
| 1419 static void | |
| 1420 ngx_my_cleanup(void *data) | |
| 1421 { | |
| 1422 u_char *msg = data; | |
| 1423 | |
| 1424 ngx_do_smth(msg); | |
| 1425 } | |
| 1426 </programlisting> | |
| 1427 | |
| 1428 </section> | |
| 1429 | |
| 1430 | |
| 1431 <section name="Shared memory" id="shared_memory"> | |
| 1432 | |
| 1433 <para> | |
| 1434 Shared memory is used by nginx to share common data between processes. | |
| 1435 Function <literal>ngx_shared_memory_add(cf, name, size, tag)</literal> adds a | |
| 1436 new shared memory entry <literal>ngx_shm_zone_t</literal> to the cycle. The | |
| 1437 function receives <literal>name</literal> and <literal>size</literal> of the | |
| 1438 zone. | |
| 1439 Each shared zone must have a unique name. | |
| 1440 If a shared zone entry with the provided name exists, the old zone entry is | |
| 1441 reused, if its tag value matches too. | |
| 1442 Mismatched tag is considered an error. | |
| 1443 Usually, the address of the module structure is passed as tag, making it | |
| 1444 possible to reuse shared zones by name within one nginx module. | |
| 1445 </para> | |
| 1446 | |
| 1447 <para> | |
| 1448 The shared memory entry structure <literal>ngx_shm_zone_t</literal> has the | |
| 1449 following fields: | |
| 1450 </para> | |
| 1451 | |
| 1452 <para> | |
| 1453 <list type="bullet"> | |
| 1454 | |
| 1455 <listitem> | |
|
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1456 <literal>init</literal> — initialization callback, called after shared zone is |
| 1899 | 1457 mapped to actual memory |
| 1458 </listitem> | |
| 1459 | |
| 1460 <listitem> | |
|
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1461 <literal>data</literal> — data context, used to pass arbitrary data to the |
| 1899 | 1462 <literal>init</literal> callback |
| 1463 </listitem> | |
| 1464 | |
| 1465 <listitem> | |
|
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1466 <literal>noreuse</literal> — flag, disabling shared zone reuse from the |
| 1899 | 1467 old cycle |
| 1468 </listitem> | |
| 1469 | |
| 1470 <listitem> | |
|
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1471 <literal>tag</literal> — shared zone tag |
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1472 </listitem> |
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1473 |
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1474 <listitem> |
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1475 <literal>shm</literal> — platform-specific object of type |
| 1899 | 1476 <literal>ngx_shm_t</literal>, having at least the following fields: |
| 1477 <list type="bullet"> | |
| 1478 | |
| 1479 <listitem> | |
|
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1480 <literal>addr</literal> — mapped shared memory address, initially NULL |
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1481 </listitem> |
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1482 |
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1483 <listitem> |
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1484 <literal>size</literal> — shared memory size |
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1485 </listitem> |
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1486 |
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1487 <listitem> |
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1488 <literal>name</literal> — shared memory name |
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1489 </listitem> |
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1490 |
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1491 <listitem> |
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1492 <literal>log</literal> — shared memory log |
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1493 </listitem> |
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1494 |
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1495 <listitem> |
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1496 <literal>exists</literal> — flag, showing that shared memory was inherited |
| 1899 | 1497 from the master process (Windows-specific) |
| 1498 </listitem> | |
| 1499 | |
| 1500 </list> | |
| 1501 </listitem> | |
| 1502 | |
| 1503 </list> | |
| 1504 </para> | |
| 1505 | |
| 1506 <para> | |
| 1507 Shared zone entries are mapped to actual memory in | |
| 1508 <literal>ngx_init_cycle()</literal> after configuration is parsed. | |
| 1509 On POSIX systems, <literal>mmap()</literal> syscall is used to create shared | |
| 1510 anonymous mapping. | |
| 1511 On Windows, <literal>CreateFileMapping()/MapViewOfFileEx()</literal> pair is | |
| 1512 used. | |
| 1513 </para> | |
| 1514 | |
| 1515 <para> | |
| 1516 For allocating in shared memory, nginx provides slab pool | |
| 1517 <literal>ngx_slab_pool_t</literal>. | |
| 1518 In each nginx shared zone, a slab pool is automatically created for allocating | |
| 1519 memory in that zone. | |
| 1520 The pool is located in the beginning of the shared zone and can be accessed by | |
| 1521 the expression <literal>(ngx_slab_pool_t *) shm_zone->shm.addr</literal>. | |
| 1522 Allocation in shared zone is done by calling one of the functions | |
| 1523 <literal>ngx_slab_alloc(pool, size)/ngx_slab_calloc(pool, size)</literal>. | |
| 1524 Memory is freed by calling <literal>ngx_slab_free(pool, p)</literal>. | |
| 1525 </para> | |
| 1526 | |
| 1527 <para> | |
| 1528 Slab pool divides all shared zone into pages. | |
| 1529 Each page is used for allocating objects of the same size. | |
| 1530 Only the sizes which are powers of 2, and not less than 8, are considered. | |
| 1531 Other sizes are rounded up to one of these values. | |
| 1532 For each page, a bitmask is kept, showing which blocks within that page are in | |
| 1533 use and which are free for allocation. | |
| 1534 For sizes greater than half-page (usually, 2048 bytes), allocation is done by | |
| 1535 entire pages. | |
| 1536 </para> | |
| 1537 | |
| 1538 <para> | |
| 1539 To protect data in shared memory from concurrent access, mutex is available in | |
| 1540 the <literal>mutex</literal> field of <literal>ngx_slab_pool_t</literal>. | |
| 1541 The mutex is used by the slab pool while allocating and freeing memory. | |
| 1542 However, it can be used to protect any other user data structures, | |
| 1543 allocated in the shared zone. | |
| 1544 Locking is done by calling | |
| 1545 <literal>ngx_shmtx_lock(&shpool->mutex)</literal>, unlocking is done by | |
| 1546 calling <literal>ngx_shmtx_unlock(&shpool->mutex)</literal>. | |
| 1547 </para> | |
| 1548 | |
| 1549 | |
| 1550 <programlisting> | |
| 1551 ngx_str_t name; | |
| 1552 ngx_foo_ctx_t *ctx; | |
| 1553 ngx_shm_zone_t *shm_zone; | |
| 1554 | |
| 1555 ngx_str_set(&name, "foo"); | |
| 1556 | |
| 1557 /* allocate shared zone context */ | |
| 1558 ctx = ngx_pcalloc(cf->pool, sizeof(ngx_foo_ctx_t)); | |
| 1559 if (ctx == NULL) { | |
| 1560 /* error */ | |
| 1561 } | |
| 1562 | |
| 1563 /* add an entry for 65k shared zone */ | |
| 1564 shm_zone = ngx_shared_memory_add(cf, &name, 65536, &ngx_foo_module); | |
| 1565 if (shm_zone == NULL) { | |
| 1566 /* error */ | |
| 1567 } | |
| 1568 | |
| 1569 /* register init callback and context */ | |
| 1570 shm_zone->init = ngx_foo_init_zone; | |
| 1571 shm_zone->data = ctx; | |
| 1572 | |
| 1573 | |
| 1574 ... | |
| 1575 | |
| 1576 | |
| 1577 static ngx_int_t | |
| 1578 ngx_foo_init_zone(ngx_shm_zone_t *shm_zone, void *data) | |
| 1579 { | |
| 1580 ngx_foo_ctx_t *octx = data; | |
| 1581 | |
| 1582 size_t len; | |
| 1583 ngx_foo_ctx_t *ctx; | |
| 1584 ngx_slab_pool_t *shpool; | |
| 1585 | |
| 1586 value = shm_zone->data; | |
| 1587 | |
| 1588 if (octx) { | |
| 1589 /* reusing a shared zone from old cycle */ | |
| 1590 ctx->value = octx->value; | |
| 1591 return NGX_OK; | |
| 1592 } | |
| 1593 | |
| 1594 shpool = (ngx_slab_pool_t *) shm_zone->shm.addr; | |
| 1595 | |
| 1596 if (shm_zone->shm.exists) { | |
| 1597 /* initialize shared zone context in Windows nginx worker */ | |
| 1598 ctx->value = shpool->data; | |
| 1599 return NGX_OK; | |
| 1600 } | |
| 1601 | |
| 1602 /* initialize shared zone */ | |
| 1603 | |
| 1604 ctx->value = ngx_slab_alloc(shpool, sizeof(ngx_uint_t)); | |
| 1605 if (ctx->value == NULL) { | |
| 1606 return NGX_ERROR; | |
| 1607 } | |
| 1608 | |
| 1609 shpool->data = ctx->value; | |
| 1610 | |
| 1611 return NGX_OK; | |
| 1612 } | |
| 1613 </programlisting> | |
| 1614 | |
| 1615 </section> | |
| 1616 | |
| 1617 | |
| 1618 </section> | |
| 1619 | |
| 1620 | |
| 1621 <section name="Logging" id="logging"> | |
| 1622 | |
| 1623 <para> | |
| 1624 For logging nginx code uses <literal>ngx_log_t</literal> objects. | |
| 1625 Nginx logger provides support for several types of output: | |
| 1626 | |
| 1627 <list type="bullet"> | |
| 1628 | |
| 1629 <listitem> | |
|
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1630 stderr — logging to standard error output |
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1631 </listitem> |
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1632 |
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1633 <listitem> |
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1634 file — logging to file |
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1635 </listitem> |
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1636 |
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1637 <listitem> |
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1638 syslog — logging to syslog |
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1639 </listitem> |
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1640 |
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1641 <listitem> |
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1642 memory — logging to internal memory storage for development purposes. |
| 1899 | 1643 The memory could be accessed later with debugger |
| 1644 </listitem> | |
| 1645 | |
| 1646 </list> | |
| 1647 </para> | |
| 1648 | |
| 1649 <para> | |
| 1650 A logger instance may actually be a chain of loggers, linked to each other with | |
| 1651 the <literal>next</literal> field. | |
| 1652 Each message is written to all loggers in chain. | |
| 1653 </para> | |
| 1654 | |
| 1655 <para> | |
| 1656 Each logger has an error level which limits the messages written to that log. | |
| 1657 The following error levels are supported by nginx: | |
| 1658 </para> | |
| 1659 | |
| 1660 <para> | |
| 1661 <list type="bullet"> | |
| 1662 | |
| 1663 <listitem> | |
| 1664 <literal>NGX_LOG_EMERG</literal> | |
| 1665 </listitem> | |
| 1666 | |
| 1667 <listitem> | |
| 1668 <literal>NGX_LOG_ALERT</literal> | |
| 1669 </listitem> | |
| 1670 | |
| 1671 <listitem> | |
| 1672 <literal>NGX_LOG_CRIT</literal> | |
| 1673 </listitem> | |
| 1674 | |
| 1675 <listitem> | |
| 1676 <literal>NGX_LOG_ERR</literal> | |
| 1677 </listitem> | |
| 1678 | |
| 1679 <listitem> | |
| 1680 <literal>NGX_LOG_WARN</literal> | |
| 1681 </listitem> | |
| 1682 | |
| 1683 <listitem> | |
| 1684 <literal>NGX_LOG_NOTICE</literal> | |
| 1685 </listitem> | |
| 1686 | |
| 1687 <listitem> | |
| 1688 <literal>NGX_LOG_INFO</literal> | |
| 1689 </listitem> | |
| 1690 | |
| 1691 <listitem> | |
| 1692 <literal>NGX_LOG_DEBUG</literal> | |
| 1693 </listitem> | |
| 1694 | |
| 1695 </list> | |
| 1696 </para> | |
| 1697 | |
| 1698 <para> | |
| 1699 For debug logging, debug mask is checked as well. The following debug masks | |
| 1700 exist: | |
| 1701 </para> | |
| 1702 | |
| 1703 <para> | |
| 1704 <list type="bullet"> | |
| 1705 | |
| 1706 <listitem> | |
| 1707 <literal>NGX_LOG_DEBUG_CORE</literal> | |
| 1708 </listitem> | |
| 1709 | |
| 1710 <listitem> | |
| 1711 <literal>NGX_LOG_DEBUG_ALLOC</literal> | |
| 1712 </listitem> | |
| 1713 | |
| 1714 <listitem> | |
| 1715 <literal>NGX_LOG_DEBUG_MUTEX</literal> | |
| 1716 </listitem> | |
| 1717 | |
| 1718 <listitem> | |
| 1719 <literal>NGX_LOG_DEBUG_EVENT</literal> | |
| 1720 </listitem> | |
| 1721 | |
| 1722 <listitem> | |
| 1723 <literal>NGX_LOG_DEBUG_HTTP</literal> | |
| 1724 </listitem> | |
| 1725 | |
| 1726 <listitem> | |
| 1727 <literal>NGX_LOG_DEBUG_MAIL</literal> | |
| 1728 </listitem> | |
| 1729 | |
| 1730 <listitem> | |
| 1731 <literal>NGX_LOG_DEBUG_STREAM</literal> | |
| 1732 </listitem> | |
| 1733 | |
| 1734 </list> | |
| 1735 </para> | |
| 1736 | |
| 1737 <para> | |
| 1738 Normally, loggers are created by existing nginx code from | |
| 1739 <literal>error_log</literal> directives and are available at nearly every stage | |
| 1740 of processing in cycle, configuration, client connection and other objects. | |
| 1741 </para> | |
| 1742 | |
| 1743 <para> | |
| 1744 Nginx provides the following logging macros: | |
| 1745 </para> | |
| 1746 | |
| 1747 <para> | |
| 1748 <list type="bullet"> | |
| 1749 | |
| 1750 <listitem> | |
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1751 <literal>ngx_log_error(level, log, err, fmt, ...)</literal> — error logging |
| 1899 | 1752 </listitem> |
| 1753 | |
| 1754 <listitem> | |
| 1755 <literal>ngx_log_debug0(level, log, err, fmt)</literal>, | |
|
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1756 <literal>ngx_log_debug1(level, log, err, fmt, arg1)</literal> etc — debug |
| 1899 | 1757 logging, up to 8 formatting arguments are supported |
| 1758 </listitem> | |
| 1759 | |
| 1760 </list> | |
| 1761 </para> | |
| 1762 | |
| 1763 <para> | |
| 1764 A log message is formatted in a buffer of size | |
| 1765 <literal>NGX_MAX_ERROR_STR</literal> (currently, 2048 bytes) on stack. | |
| 1766 The message is prepended with error level, process PID, connection id (stored | |
| 1767 in <literal>log->connection</literal>) and system error text. | |
| 1768 For non-debug messages <literal>log->handler</literal> is called as well to | |
| 1769 prepend more specific information to the log message. | |
| 1770 HTTP module sets <literal>ngx_http_log_error()</literal> function as log | |
| 1771 handler to log client and server addresses, current action (stored in | |
| 1772 <literal>log->action</literal>), client request line, server name etc. | |
| 1773 </para> | |
| 1774 | |
| 1775 <para> | |
| 1776 Example: | |
| 1777 </para> | |
| 1778 | |
| 1779 | |
| 1780 <programlisting> | |
| 1781 /* specify what is currently done */ | |
| 1782 log->action = "sending mp4 to client”; | |
| 1783 | |
| 1784 /* error and debug log */ | |
| 1785 ngx_log_error(NGX_LOG_INFO, c->log, 0, "client prematurely | |
| 1786 closed connection”); | |
| 1787 | |
| 1788 ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, | |
| 1789 "mp4 start:%ui, length:%ui”, mp4->start, mp4->length); | |
| 1790 </programlisting> | |
| 1791 | |
| 1792 <para> | |
| 1793 Logging result: | |
| 1794 </para> | |
| 1795 | |
| 1796 | |
| 1797 <programlisting> | |
| 1798 2016/09/16 22:08:52 [info] 17445#0: *1 client prematurely closed connection while | |
| 1799 sending mp4 to client, client: 127.0.0.1, server: , request: "GET /file.mp4 HTTP/1.1” | |
| 1800 2016/09/16 23:28:33 [debug] 22140#0: *1 mp4 start:0, length:10000 | |
| 1801 </programlisting> | |
| 1802 | |
| 1803 </section> | |
| 1804 | |
| 1805 | |
| 1806 <section name="Cycle" id="cycle"> | |
| 1807 | |
| 1808 <para> | |
| 1809 Cycle object keeps nginx runtime context, created from a specific | |
| 1810 configuration. | |
| 1811 The type of the cycle is <literal>ngx_cycle_t</literal>. | |
| 1812 Upon configuration reload a new cycle is created from the new version of nginx | |
| 1813 configuration. | |
| 1814 The old cycle is usually deleted after a new one is successfully created. | |
| 1815 Currently active cycle is held in the <literal>ngx_cycle</literal> global | |
| 1816 variable and is inherited by newly started nginx workers. | |
| 1817 </para> | |
| 1818 | |
| 1819 <para> | |
| 1820 A cycle is created by the function <literal>ngx_init_cycle()</literal>. | |
| 1821 The function receives the old cycle as the argument. | |
| 1822 It's used to locate the configuration file and inherit as much resources as | |
| 1823 possible from the old cycle to keep nginx running smoothly. | |
|
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1824 When nginx starts, a fake cycle called “init cycle” is created and is then |
| 1899 | 1825 replaced by a normal cycle, built from configuration. |
| 1826 </para> | |
| 1827 | |
| 1828 <para> | |
| 1829 Some members of the cycle: | |
| 1830 </para> | |
| 1831 | |
| 1832 <para> | |
| 1833 <list type="bullet"> | |
| 1834 | |
| 1835 <listitem> | |
|
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1836 <literal>pool</literal> — cycle pool. Created for each new cycle |
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1837 </listitem> |
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1838 |
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1839 <listitem> |
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1840 <literal>log</literal> — cycle log. Initially, this log is inherited from the |
| 1899 | 1841 old cycle. |
| 1842 After reading configuration, this member is set to point to | |
| 1843 <literal>new_log</literal> | |
| 1844 </listitem> | |
| 1845 | |
| 1846 <listitem> | |
|
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1847 <literal>new_log</literal> — cycle log, created by the configuration. |
| 1899 | 1848 It's affected by the root scope <literal>error_log</literal> directive |
| 1849 </listitem> | |
| 1850 | |
| 1851 <listitem> | |
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1852 <literal>connections</literal>, <literal>connections_n</literal> — per-worker |
| 1899 | 1853 array of connections of type <literal>ngx_connection_t</literal>, created by |
| 1854 the event module while initializing each nginx worker. | |
| 1855 The number of connections is set by the <literal>worker_connections</literal> | |
| 1856 directive | |
| 1857 </listitem> | |
| 1858 | |
| 1859 <listitem> | |
| 1860 <literal>free_connections</literal>, | |
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1861 <literal>free_connections_n</literal> — the and number of currently available |
| 1899 | 1862 connections. |
| 1863 If no connections are available, nginx worker refuses to accept new clients | |
| 1864 </listitem> | |
| 1865 | |
| 1866 <listitem> | |
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1867 <literal>files</literal>, <literal>files_n</literal> — array for mapping file |
| 1899 | 1868 descriptors to nginx connections. |
| 1869 This mapping is used by the event modules, having the | |
| 1870 <literal>NGX_USE_FD_EVENT</literal> flag (currently, it's poll and devpoll) | |
| 1871 </listitem> | |
| 1872 | |
| 1873 <listitem> | |
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1874 <literal>conf_ctx</literal> — array of core module configurations. |
| 1899 | 1875 The configurations are created and filled while reading nginx configuration |
| 1876 files | |
| 1877 </listitem> | |
| 1878 | |
| 1879 <listitem> | |
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1880 <literal>modules</literal>, <literal>modules_n</literal> — array of modules |
| 1899 | 1881 <literal>ngx_module_t</literal>, both static and dynamic, loaded by current |
| 1882 configuration | |
| 1883 </listitem> | |
| 1884 | |
| 1885 <listitem> | |
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1886 <literal>listening</literal> — array of listening objects |
| 1899 | 1887 <literal>ngx_listening_t</literal>. |
| 1888 Listening objects are normally added by the the <literal>listen</literal> | |
| 1889 directive of different modules which call the | |
| 1890 <literal>ngx_create_listening()</literal> function. | |
| 1891 Based on listening objects, listen sockets are created by nginx | |
| 1892 </listitem> | |
| 1893 | |
| 1894 <listitem> | |
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1895 <literal>paths</literal> — array of paths <literal>ngx_path_t</literal>. |
| 1899 | 1896 Paths are added by calling the function <literal>ngx_add_path()</literal> from |
| 1897 modules which are going to operate on certain directories. | |
| 1898 These directories are created by nginx after reading configuration, if missing. | |
| 1899 Moreover, two handlers can be added for each path: | |
| 1900 | |
| 1901 <list type="bullet"> | |
| 1902 | |
| 1903 <listitem> | |
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1904 path loader — executed only once in 60 seconds after starting or reloading |
| 1899 | 1905 nginx. Normally, reads the directory and stores data in nginx shared |
|
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1906 memory. The handler is called from a dedicated nginx process “nginx |
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1907 cache loader” |
| 1899 | 1908 </listitem> |
| 1909 | |
| 1910 <listitem> | |
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1911 path manager — executed periodically. Normally, removes old files from the |
| 1899 | 1912 directory and reflects these changes in nginx memory. The handler is |
|
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1913 called from a dedicated nginx process “nginx cache manager” |
| 1899 | 1914 </listitem> |
| 1915 | |
| 1916 </list> | |
| 1917 </listitem> | |
| 1918 | |
| 1919 <listitem> | |
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1920 <literal>open_files</literal> — list of <literal>ngx_open_file_t</literal> |
| 1899 | 1921 objects. |
| 1922 An open file object is created by calling the function | |
| 1923 <literal>ngx_conf_open_file()</literal>. | |
| 1924 After reading configuration nginx opens all files from the | |
| 1925 <literal>open_files</literal> list and stores file descriptors in the | |
| 1926 <literal>fd</literal> field of each open file object. | |
| 1927 The files are opened in append mode and created if missing. | |
| 1928 The files from this list are reopened by nginx workers upon receiving the | |
| 1929 reopen signal (usually it's <literal>USR1</literal>). | |
| 1930 In this case the <literal>fd</literal> fields are changed to new descriptors. | |
| 1931 The open files are currently used for logging | |
| 1932 </listitem> | |
| 1933 | |
| 1934 <listitem> | |
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1935 <literal>shared_memory</literal> — list of shared memory zones, each added by |
| 1899 | 1936 calling the <literal>ngx_shared_memory_add()</literal> function. |
| 1937 Shared zones are mapped to the same address range in all nginx processes and | |
| 1938 are used to share common data, for example HTTP cache in-memory tree | |
| 1939 </listitem> | |
| 1940 | |
| 1941 </list> | |
| 1942 </para> | |
| 1943 | |
| 1944 </section> | |
| 1945 | |
| 1946 <section name="Buffer" id="buffer"> | |
| 1947 | |
| 1948 <para> | |
| 1949 For input/output operations, nginx provides the buffer type | |
| 1950 <literal>ngx_buf_t</literal>. | |
| 1951 Normally, it's used to hold data to be written to a destination or read from a | |
| 1952 source. | |
| 1953 Buffer can reference data in memory and in file. | |
| 1954 Technically it's possible that a buffer references both at the same time. | |
| 1955 Memory for the buffer is allocated separately and is not related to the buffer | |
| 1956 structure <literal>ngx_buf_t</literal>. | |
| 1957 </para> | |
| 1958 | |
| 1959 <para> | |
| 1960 The structure <literal>ngx_buf_t</literal> has the following fields: | |
| 1961 </para> | |
| 1962 | |
| 1963 <para> | |
| 1964 <list type="bullet"> | |
| 1965 | |
| 1966 <listitem> | |
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1967 <literal>start</literal>, <literal>end</literal> — the boundaries of memory |
| 1899 | 1968 block, allocated for the buffer |
| 1969 </listitem> | |
| 1970 | |
| 1971 <listitem> | |
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1972 <literal>pos</literal>, <literal>last</literal> — memory buffer boundaries, |
| 1899 | 1973 normally a subrange of <literal>start</literal> .. <literal>end</literal> |
| 1974 </listitem> | |
| 1975 | |
| 1976 <listitem> | |
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1977 <literal>file_pos</literal>, <literal>file_last</literal> — file buffer |
| 1899 | 1978 boundaries, these are offsets from the beginning of the file |
| 1979 </listitem> | |
| 1980 | |
| 1981 <listitem> | |
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1982 <literal>tag</literal> — unique value, used to distinguish buffers, created by |
| 1899 | 1983 different nginx module, usually, for the purpose of buffer reuse |
| 1984 </listitem> | |
| 1985 | |
| 1986 <listitem> | |
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1987 <literal>file</literal> — file object |
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1988 </listitem> |
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1989 |
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1990 <listitem> |
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1991 <literal>temporary</literal> — flag, meaning that the buffer references |
| 1899 | 1992 writable memory |
| 1993 </listitem> | |
| 1994 | |
| 1995 <listitem> | |
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1996 <literal>memory</literal> — flag, meaning that the buffer references read-only |
| 1899 | 1997 memory |
| 1998 </listitem> | |
| 1999 | |
| 2000 <listitem> | |
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2001 <literal>in_file</literal> — flag, meaning that current buffer references data |
| 1899 | 2002 in a file |
| 2003 </listitem> | |
| 2004 | |
| 2005 <listitem> | |
|
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2006 <literal>flush</literal> — flag, meaning that all data prior to this buffer |
| 1899 | 2007 should be flushed |
| 2008 </listitem> | |
| 2009 | |
| 2010 <listitem> | |
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2011 <literal>recycled</literal> — flag, meaning that the buffer can be reused and |
| 1899 | 2012 should be consumed as soon as possible |
| 2013 </listitem> | |
| 2014 | |
| 2015 <listitem> | |
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2016 <literal>sync</literal> — flag, meaning that the buffer carries no data or |
| 1899 | 2017 special signal like <literal>flush</literal> or <literal>last_buf</literal>. |
| 2018 Normally, such buffers are considered an error by nginx. This flags allows | |
| 2019 skipping the error checks | |
| 2020 </listitem> | |
| 2021 | |
| 2022 <listitem> | |
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2023 <literal>last_buf</literal> — flag, meaning that current buffer is the last in |
| 1899 | 2024 output |
| 2025 </listitem> | |
| 2026 | |
| 2027 <listitem> | |
|
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2028 <literal>last_in_chain</literal> — flag, meaning that there's no more data |
| 1899 | 2029 buffers in a (sub)request |
| 2030 </listitem> | |
| 2031 | |
| 2032 <listitem> | |
|
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2033 <literal>shadow</literal> — reference to another buffer, related to the current |
| 1899 | 2034 buffer. Usually current buffer uses data from the shadow buffer. Once current |
| 2035 buffer is consumed, the shadow buffer should normally also be marked as | |
| 2036 consumed | |
| 2037 </listitem> | |
| 2038 | |
| 2039 <listitem> | |
|
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2040 <literal>last_shadow</literal> — flag, meaning that current buffer is the last |
| 1899 | 2041 buffer, referencing a particular shadow buffer |
| 2042 </listitem> | |
| 2043 | |
| 2044 <listitem> | |
|
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2045 <literal>temp_file</literal> — flag, meaning that the buffer is in a temporary |
| 1899 | 2046 file |
| 2047 </listitem> | |
| 2048 | |
| 2049 </list> | |
| 2050 </para> | |
| 2051 | |
| 2052 <para> | |
| 2053 For input and output buffers are linked in chains. | |
| 2054 Chain is a sequence of chain links <literal>ngx_chain_t</literal>, defined as | |
| 2055 follows: | |
| 2056 </para> | |
| 2057 | |
| 2058 | |
| 2059 <programlisting> | |
| 2060 typedef struct ngx_chain_s ngx_chain_t; | |
| 2061 | |
| 2062 struct ngx_chain_s { | |
| 2063 ngx_buf_t *buf; | |
| 2064 ngx_chain_t *next; | |
| 2065 }; | |
| 2066 </programlisting> | |
| 2067 | |
| 2068 <para> | |
| 2069 Each chain link keeps a reference to its buffer and a reference to the next | |
| 2070 chain link. | |
| 2071 </para> | |
| 2072 | |
| 2073 <para> | |
| 2074 Example of using buffers and chains: | |
| 2075 </para> | |
| 2076 | |
| 2077 | |
| 2078 <programlisting> | |
| 2079 ngx_chain_t * | |
| 2080 ngx_get_my_chain(ngx_pool_t *pool) | |
| 2081 { | |
| 2082 ngx_buf_t *b; | |
| 2083 ngx_chain_t *out, *cl, **ll; | |
| 2084 | |
| 2085 /* first buf */ | |
| 2086 cl = ngx_alloc_chain_link(pool); | |
| 2087 if (cl == NULL) { /* error */ } | |
| 2088 | |
| 2089 b = ngx_calloc_buf(pool); | |
| 2090 if (b == NULL) { /* error */ } | |
| 2091 | |
| 2092 b->start = (u_char *) "foo"; | |
| 2093 b->pos = b->start; | |
| 2094 b->end = b->start + 3; | |
| 2095 b->last = b->end; | |
| 2096 b->memory = 1; /* read-only memory */ | |
| 2097 | |
| 2098 cl->buf = b; | |
| 2099 out = cl; | |
| 2100 ll = &cl->next; | |
| 2101 | |
| 2102 /* second buf */ | |
| 2103 cl = ngx_alloc_chain_link(pool); | |
| 2104 if (cl == NULL) { /* error */ } | |
| 2105 | |
| 2106 b = ngx_create_temp_buf(pool, 3); | |
| 2107 if (b == NULL) { /* error */ } | |
| 2108 | |
| 2109 b->last = ngx_cpymem(b->last, "foo", 3); | |
| 2110 | |
| 2111 cl->buf = b; | |
| 2112 cl->next = NULL; | |
| 2113 *ll = cl; | |
| 2114 | |
| 2115 return out; | |
| 2116 } | |
| 2117 </programlisting> | |
| 2118 | |
| 2119 </section> | |
| 2120 | |
| 2121 | |
| 2122 <section name="Networking" id="networking"> | |
| 2123 | |
| 2124 | |
| 2125 <!-- | |
| 2126 <section name="Network data types" id="network_data_types"> | |
| 2127 | |
| 2128 <para> | |
| 2129 TBD: ngx_addr_t, ngx_url_t, ngx_socket_t, ngx_sockaddr_t, parse url, parse | |
| 2130 address... | |
| 2131 </para> | |
| 2132 | |
| 2133 </section> | |
| 2134 --> | |
| 2135 | |
| 2136 <section name="Connection" id="connection"> | |
| 2137 | |
| 2138 <para> | |
| 2139 Connection type <literal>ngx_connection_t</literal> is a wrapper around a | |
| 2140 socket descriptor. Some of the structure fields are: | |
| 2141 </para> | |
| 2142 | |
| 2143 <para> | |
| 2144 <list type="bullet"> | |
| 2145 | |
| 2146 <listitem> | |
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2147 <literal>fd</literal> — socket descriptor |
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2148 </listitem> |
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2149 |
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2150 <listitem> |
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2151 <literal>data</literal> — arbitrary connection context. |
| 1899 | 2152 Normally, a pointer to a higher level object, built on top of the connection, |
| 2153 like HTTP request or Stream session | |
| 2154 </listitem> | |
| 2155 | |
| 2156 <listitem> | |
|
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2157 <literal>read</literal>, <literal>write</literal> — read and write events for |
| 1899 | 2158 the connection |
| 2159 </listitem> | |
| 2160 | |
| 2161 <listitem> | |
| 2162 <literal>recv</literal>, <literal>send</literal>, | |
|
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2163 <literal>recv_chain</literal>, <literal>send_chain</literal> — I/O operations |
| 1899 | 2164 for the connection |
| 2165 </listitem> | |
| 2166 | |
| 2167 <listitem> | |
|
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2168 <literal>pool</literal> — connection pool |
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2169 </listitem> |
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2170 |
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2171 <listitem> |
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2172 <literal>log</literal> — connection log |
| 1899 | 2173 </listitem> |
| 2174 | |
| 2175 <listitem> | |
| 2176 <literal>sockaddr</literal>, <literal>socklen</literal>, | |
|
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2177 <literal>addr_text</literal> — remote socket address in binary and text forms |
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2178 </listitem> |
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2179 |
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2180 <listitem> |
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2181 <literal>local_sockaddr</literal>, <literal>local_socklen</literal> — local |
| 1899 | 2182 socket address in binary form. |
| 2183 Initially, these fields are empty. | |
| 2184 Function <literal>ngx_connection_local_sockaddr()</literal> should be used to | |
| 2185 get socket local address | |
| 2186 </listitem> | |
| 2187 | |
| 2188 <listitem> | |
| 2189 <literal>proxy_protocol_addr</literal>, <literal>proxy_protocol_port</literal> | |
| 2190 - PROXY protocol client address and port, if PROXY protocol is enabled for the | |
| 2191 connection | |
| 2192 </listitem> | |
| 2193 | |
| 2194 <listitem> | |
|
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2195 <literal>ssl</literal> — nginx connection SSL context |
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2196 </listitem> |
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2197 |
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2198 <listitem> |
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2199 <literal>reusable</literal> — flag, meaning, that the connection is at the |
| 1899 | 2200 state, when it can be reused |
| 2201 </listitem> | |
| 2202 | |
| 2203 <listitem> | |
|
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2204 <literal>close</literal> — flag, meaning, that the connection is being reused |
| 1899 | 2205 and should be closed |
| 2206 </listitem> | |
| 2207 | |
| 2208 </list> | |
| 2209 </para> | |
| 2210 | |
| 2211 <para> | |
| 2212 An nginx connection can transparently encapsulate SSL layer. | |
| 2213 In this case the connection <literal>ssl</literal> field holds a pointer to an | |
| 2214 <literal>ngx_ssl_connection_t</literal> structure, keeping all SSL-related data | |
| 2215 for the connection, including <literal>SSL_CTX</literal> and | |
| 2216 <literal>SSL</literal>. | |
| 2217 The handlers <literal>recv</literal>, <literal>send</literal>, | |
| 2218 <literal>recv_chain</literal>, <literal>send_chain</literal> are set as well to | |
| 2219 SSL functions. | |
| 2220 </para> | |
| 2221 | |
| 2222 <para> | |
| 2223 The number of connections per nginx worker is limited by the | |
| 2224 <literal>worker_connections</literal> value. | |
| 2225 All connection structures are pre-created when a worker starts and stored in | |
| 2226 the <literal>connections</literal> field of the cycle object. | |
| 2227 To reach out for a connection structure, <literal>ngx_get_connection(s, | |
| 2228 log)</literal> function is used. | |
| 2229 The function receives a socket descriptor <literal>s</literal> which needs to | |
| 2230 be wrapped in a connection structure. | |
| 2231 </para> | |
| 2232 | |
| 2233 <para> | |
| 2234 Since the number of connections per worker is limited, nginx provides a | |
| 2235 way to grab connections which are currently in use. | |
| 2236 To enable or disable reuse of a connection, function | |
| 2237 <literal>ngx_reusable_connection(c, reusable)</literal> is called. | |
| 2238 Calling <literal>ngx_reusable_connection(c, 1)</literal> sets the | |
| 2239 <literal>reuse</literal> flag of the connection structure and inserts the | |
| 2240 connection in the <literal>reusable_connections_queue</literal> of the cycle. | |
| 2241 Whenever <literal>ngx_get_connection()</literal> finds out there are no | |
| 2242 available connections in the <literal>free_connections</literal> list of the | |
| 2243 cycle, it calls <literal>ngx_drain_connections()</literal> to release a | |
| 2244 specific number of reusable connections. | |
| 2245 For each such connection, the <literal>close</literal> flag is set and its read | |
| 2246 handler is called which is supposed to free the connection by calling | |
| 2247 <literal>ngx_close_connection(c)</literal> and make it available for reuse. | |
| 2248 To exit the state when a connection can be reused | |
| 2249 <literal>ngx_reusable_connection(c, 0)</literal> is called. | |
| 2250 An example of reusable connections in nginx is HTTP client connections which | |
| 2251 are marked as reusable until some data is received from the client. | |
| 2252 </para> | |
| 2253 | |
| 2254 </section> | |
| 2255 | |
| 2256 | |
| 2257 </section> | |
| 2258 | |
| 2259 | |
| 2260 <section name="Events" id="events"> | |
| 2261 | |
| 2262 | |
| 2263 <section name="Event" id="event"> | |
| 2264 | |
| 2265 <para> | |
| 2266 Event object <literal>ngx_event_t</literal> in nginx provides a way to be | |
| 2267 notified of a specific event happening. | |
| 2268 </para> | |
| 2269 | |
| 2270 <para> | |
| 2271 Some of the fields of the <literal>ngx_event_t</literal> are: | |
| 2272 </para> | |
| 2273 | |
| 2274 <para> | |
| 2275 <list type="bullet"> | |
| 2276 | |
| 2277 <listitem> | |
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2278 <literal>data</literal> — arbitrary event context, used in event handler, |
| 1899 | 2279 usually, a pointer to a connection, tied with the event |
| 2280 </listitem> | |
| 2281 | |
| 2282 <listitem> | |
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2283 <literal>handler</literal> — callback function to be invoked when the event |
| 1899 | 2284 happens |
| 2285 </listitem> | |
| 2286 | |
| 2287 <listitem> | |
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2288 <literal>write</literal> — flag, meaning that this is the write event. |
| 1899 | 2289 Used to distinguish between read and write events |
| 2290 </listitem> | |
| 2291 | |
| 2292 <listitem> | |
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2293 <literal>active</literal> — flag, meaning that the event is registered for |
| 1899 | 2294 receiving I/O notifications, normally from notification mechanisms like epoll, |
| 2295 kqueue, poll | |
| 2296 </listitem> | |
| 2297 | |
| 2298 <listitem> | |
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2299 <literal>ready</literal> — flag, meaning that the event has received an |
| 1899 | 2300 I/O notification |
| 2301 </listitem> | |
| 2302 | |
| 2303 <listitem> | |
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2304 <literal>delayed</literal> — flag, meaning that I/O is delayed due to rate |
| 1899 | 2305 limiting |
| 2306 </listitem> | |
| 2307 | |
| 2308 <listitem> | |
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2309 <literal>timer</literal> — Red-Black tree node for inserting the event into |
| 1899 | 2310 the timer tree |
| 2311 </listitem> | |
| 2312 | |
| 2313 <listitem> | |
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2314 <literal>timer_set</literal> — flag, meaning that the event timer is set, |
| 1899 | 2315 but not yet expired |
| 2316 </listitem> | |
| 2317 | |
| 2318 <listitem> | |
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2319 <literal>timedout</literal> — flag, meaning that the event timer has expired |
|
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2320 </listitem> |
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2321 |
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2322 <listitem> |
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2323 <literal>eof</literal> — read event flag, meaning that the eof has happened |
| 1899 | 2324 while reading data |
| 2325 </listitem> | |
| 2326 | |
| 2327 <listitem> | |
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2328 <literal>pending_eof</literal> — flag, meaning that the eof is pending on the |
| 1899 | 2329 socket, even though there may be some data available before it. |
| 2330 The flag is delivered via <literal>EPOLLRDHUP</literal> epoll event or | |
| 2331 <literal>EV_EOF</literal> kqueue flag | |
| 2332 </listitem> | |
| 2333 | |
| 2334 <listitem> | |
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2335 <literal>error</literal> — flag, meaning that an error has happened while |
| 1899 | 2336 reading (for read event) or writing (for write event) |
| 2337 </listitem> | |
| 2338 | |
| 2339 <listitem> | |
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2340 <literal>cancelable</literal> — timer event flag, meaning that the event |
| 1899 | 2341 handler should be called while performing nginx worker graceful shutdown, event |
| 2342 though event timeout has not yet expired. The flag provides a way to finalize | |
| 2343 certain activities, for example, flush log files | |
| 2344 </listitem> | |
| 2345 | |
| 2346 <listitem> | |
|
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2347 <literal>posted</literal> — flag, meaning that the event is posted to queue |
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2348 </listitem> |
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2349 |
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2350 <listitem> |
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2351 <literal>queue</literal> — queue node for posting the event to a queue |
| 1899 | 2352 </listitem> |
| 2353 | |
| 2354 </list> | |
| 2355 </para> | |
| 2356 | |
| 2357 </section> | |
| 2358 | |
| 2359 | |
| 2360 <section name="I/O events" id="i_o_events"> | |
| 2361 | |
| 2362 <para> | |
| 2363 Each connection, received with the | |
| 2364 <literal>ngx_get_connection()</literal> call, has two events attached to it: | |
| 2365 <literal>c->read</literal> and <literal>c->write</literal>. | |
| 2366 These events are used to receive notifications about the socket being ready for | |
| 2367 reading or writing. | |
| 2368 All such events operate in Edge-Triggered mode, meaning that they only trigger | |
| 2369 notifications when the state of the socket changes. | |
| 2370 For example, doing a partial read on a socket will not make nginx deliver a | |
| 2371 repeated read notification until more data arrive in the socket. | |
| 2372 Even when the underlying I/O notification mechanism is essentially | |
| 2373 Level-Triggered (poll, select etc), nginx will turn the notifications into | |
| 2374 Edge-Triggered. | |
| 2375 To make nginx event notifications consistent across all notifications systems | |
| 2376 on different platforms, it's required, that the functions | |
| 2377 <literal>ngx_handle_read_event(rev, flags)</literal> and | |
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2378 <literal>ngx_handle_write_event(wev, lowat)</literal> are called after handling |
| 1899 | 2379 an I/O socket notification or calling any I/O functions on that socket. |
| 2380 Normally, these functions are called once in the end of each read or write | |
| 2381 event handler. | |
| 2382 </para> | |
| 2383 | |
| 2384 </section> | |
| 2385 | |
| 2386 | |
| 2387 <section name="Timer events" id="timer_events"> | |
| 2388 | |
| 2389 <para> | |
| 2390 An event can be set to notify a timeout expiration. | |
| 2391 The function <literal>ngx_add_timer(ev, timer)</literal> sets a timeout for an | |
| 2392 event, <literal>ngx_del_timer(ev)</literal> deletes a previously set timeout. | |
| 2393 Timeouts currently set for all existing events, are kept in a global timeout | |
| 2394 Red-Black tree <literal>ngx_event_timer_rbtree</literal>. | |
| 2395 The key in that tree has the type <literal>ngx_msec_t</literal> and is the time | |
| 2396 in milliseconds since the beginning of January 1, 1970 (modulus | |
| 2397 <literal>ngx_msec_t</literal> max value) at which the event should expire. | |
| 2398 The tree structure provides fast inserting and deleting operations, as well as | |
| 2399 accessing the nearest timeouts. | |
| 2400 The latter is used by nginx to find out for how long to wait for I/O events | |
| 2401 and for expiring timeout events afterwards. | |
| 2402 </para> | |
| 2403 | |
| 2404 </section> | |
| 2405 | |
| 2406 | |
| 2407 <section name="Posted events" id="posted_events"> | |
| 2408 | |
| 2409 <para> | |
| 2410 An event can be posted which means that its handler will be called at some | |
| 2411 point later within the current event loop iteration. | |
| 2412 Posting events is a good practice for simplifying code and escaping stack | |
| 2413 overflows. | |
| 2414 Posted events are held in a post queue. | |
| 2415 The macro <literal>ngx_post_event(ev, q)</literal> posts the event | |
| 2416 <literal>ev</literal> to the post queue <literal>q</literal>. | |
| 2417 Macro <literal>ngx_delete_posted_event(ev)</literal> deletes the event | |
| 2418 <literal>ev</literal> from whatever queue it's currently posted. | |
| 2419 Normally, events are posted to the <literal>ngx_posted_events</literal> queue. | |
|
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2420 This queue is processed late in the event loop — after all I/O and timer |
| 1899 | 2421 events are already handled. |
| 2422 The function <literal>ngx_event_process_posted()</literal> is called to process | |
| 2423 an event queue. | |
| 2424 This function calls event handlers until the queue is not empty. This means | |
| 2425 that a posted event handler can post more events to be processed within the | |
| 2426 current event loop iteration. | |
| 2427 </para> | |
| 2428 | |
| 2429 <para> | |
| 2430 Example: | |
| 2431 </para> | |
| 2432 | |
| 2433 | |
| 2434 <programlisting> | |
| 2435 void | |
| 2436 ngx_my_connection_read(ngx_connection_t *c) | |
| 2437 { | |
| 2438 ngx_event_t *rev; | |
| 2439 | |
| 2440 rev = c->read; | |
| 2441 | |
| 2442 ngx_add_timer(rev, 1000); | |
| 2443 | |
| 2444 rev->handler = ngx_my_read_handler; | |
| 2445 | |
| 2446 ngx_my_read(rev); | |
| 2447 } | |
| 2448 | |
| 2449 | |
| 2450 void | |
| 2451 ngx_my_read_handler(ngx_event_t *rev) | |
| 2452 { | |
| 2453 ssize_t n; | |
| 2454 ngx_connection_t *c; | |
| 2455 u_char buf[256]; | |
| 2456 | |
| 2457 if (rev->timedout) { /* timeout expired */ } | |
| 2458 | |
| 2459 c = rev->data; | |
| 2460 | |
| 2461 while (rev->ready) { | |
| 2462 n = c->recv(c, buf, sizeof(buf)); | |
| 2463 | |
| 2464 if (n == NGX_AGAIN) { | |
| 2465 break; | |
| 2466 } | |
| 2467 | |
| 2468 if (n == NGX_ERROR) { /* error */ } | |
| 2469 | |
| 2470 /* process buf */ | |
| 2471 } | |
| 2472 | |
| 2473 if (ngx_handle_read_event(rev, 0) != NGX_OK) { /* error */ } | |
| 2474 } | |
| 2475 </programlisting> | |
| 2476 | |
| 2477 </section> | |
| 2478 | |
| 2479 | |
| 2480 <section name="Event loop" id="event_loop"> | |
| 2481 | |
| 2482 <para> | |
| 2483 All nginx processes which do I/O, have an event loop. | |
| 2484 The only type of process which does not have I/O, is nginx master process which | |
| 2485 spends most of its time in <literal>sigsuspend()</literal> call waiting for | |
| 2486 signals to arrive. | |
| 2487 Event loop is implemented in <literal>ngx_process_events_and_timers()</literal> | |
| 2488 function. | |
| 2489 This function is called repeatedly until the process exits. | |
| 2490 It has the following stages: | |
| 2491 </para> | |
| 2492 | |
| 2493 <para> | |
| 2494 <list type="bullet"> | |
| 2495 | |
| 2496 <listitem> | |
| 2497 find nearest timeout by calling <literal>ngx_event_find_timer()</literal>. | |
| 2498 This function finds the leftmost timer tree node and returns the number of | |
| 2499 milliseconds until that node expires | |
| 2500 </listitem> | |
| 2501 | |
| 2502 <listitem> | |
| 2503 process I/O events by calling a handler, specific to event notification | |
| 2504 mechanism, chosen by nginx configuration. | |
| 2505 This handler waits for at least one I/O event to happen, but no longer, than | |
| 2506 the nearest timeout. | |
| 2507 For each read or write event which has happened, the <literal>ready</literal> | |
| 2508 flag is set and its handler is called. | |
| 2509 For Linux, normally, the <literal>ngx_epoll_process_events()</literal> handler | |
| 2510 is used which calls <literal>epoll_wait()</literal> to wait for I/O events | |
| 2511 </listitem> | |
| 2512 | |
| 2513 <listitem> | |
| 2514 expire timers by calling <literal>ngx_event_expire_timers()</literal>. | |
| 2515 The timer tree is iterated from the leftmost element to the right until a not | |
| 2516 yet expired timeout is found. | |
| 2517 For each expired node the <literal>timedout</literal> event flag is set, | |
| 2518 <literal>timer_set</literal> flag is reset, and the event handler is called | |
| 2519 </listitem> | |
| 2520 | |
| 2521 <listitem> | |
| 2522 process posted events by calling <literal>ngx_event_process_posted()</literal>. | |
| 2523 The function repeatedly removes the first element from the posted events | |
| 2524 queue and calls its handler until the queue gets empty | |
| 2525 </listitem> | |
| 2526 | |
| 2527 </list> | |
| 2528 </para> | |
| 2529 | |
| 2530 <para> | |
| 2531 All nginx processes handle signals as well. | |
| 2532 Signal handlers only set global variables which are checked after the | |
| 2533 <literal>ngx_process_events_and_timers()</literal> call. | |
| 2534 </para> | |
| 2535 | |
| 2536 </section> | |
| 2537 | |
| 2538 | |
| 2539 </section> | |
| 2540 | |
| 2541 | |
| 2542 <section name="Processes" id="processes"> | |
| 2543 | |
| 2544 <para> | |
| 2545 There are several types of processes in nginx. | |
| 2546 The type of current process is kept in the <literal>ngx_process</literal> | |
| 2547 global variable: | |
| 2548 </para> | |
| 2549 | |
| 2550 <list type="bullet"> | |
| 2551 | |
| 2552 <listitem> | |
| 2553 | |
| 2554 <para> | |
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2555 <literal>NGX_PROCESS_MASTER</literal> — the master process runs the |
| 1899 | 2556 <literal>ngx_master_process_cycle()</literal> function. |
| 2557 Master process does not have any I/O and responds only to signals. | |
| 2558 It reads configuration, creates cycles, starts and controls child processes | |
| 2559 </para> | |
| 2560 | |
| 2561 | |
| 2562 </listitem> | |
| 2563 | |
| 2564 <listitem> | |
| 2565 | |
| 2566 <para> | |
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2567 <literal>NGX_PROCESS_WORKER</literal> — the worker process runs the |
| 1899 | 2568 <literal>ngx_worker_process_cycle()</literal> function. |
| 2569 Worker processes are started by master and handle client connections. | |
| 2570 They also respond to signals and channel commands, sent from master | |
| 2571 </para> | |
| 2572 | |
| 2573 | |
| 2574 </listitem> | |
| 2575 | |
| 2576 <listitem> | |
| 2577 | |
| 2578 <para> | |
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2579 <literal>NGX_PROCESS_SINGLE</literal> — single process is the only type |
| 1899 | 2580 of processes which exist in the <literal>master_process off</literal> mode. |
| 2581 The cycle function for this process is | |
| 2582 <literal>ngx_single_process_cycle()</literal>. | |
| 2583 This process creates cycles and handles client connections | |
| 2584 </para> | |
| 2585 | |
| 2586 | |
| 2587 </listitem> | |
| 2588 | |
| 2589 <listitem> | |
| 2590 | |
| 2591 <para> | |
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2592 <literal>NGX_PROCESS_HELPER</literal> — currently, there are two types of |
| 1899 | 2593 helper processes: cache manager and cache loader. |
| 2594 Both of them share the same cycle function | |
| 2595 <literal>ngx_cache_manager_process_cycle()</literal>. | |
| 2596 </para> | |
| 2597 | |
| 2598 | |
| 2599 </listitem> | |
| 2600 | |
| 2601 </list> | |
| 2602 | |
| 2603 <para> | |
| 2604 All nginx processes handle the following signals: | |
| 2605 </para> | |
| 2606 | |
| 2607 <list type="bullet"> | |
| 2608 | |
| 2609 <listitem> | |
| 2610 | |
| 2611 <para> | |
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2612 <literal>NGX_SHUTDOWN_SIGNAL</literal> (<literal>SIGQUIT</literal>) — graceful |
| 1899 | 2613 shutdown. |
| 2614 Upon receiving this signal master process sends shutdown signal to all child | |
| 2615 processes. | |
| 2616 When no child processes are left, master destroys cycle pool and exits. | |
| 2617 A worker process which received this signal, closes all listening sockets and | |
| 2618 waits until timeout tree becomes empty, then destroys cycle pool and exits. | |
| 2619 A cache manager process exits right after receiving this signal. | |
| 2620 The variable <literal>ngx_quit</literal> is set to one after receiving this | |
| 2621 signal and immediately reset after being processed. | |
| 2622 The variable <literal>ngx_exiting</literal> is set to one when worker process | |
| 2623 is in shutdown state | |
| 2624 </para> | |
| 2625 | |
| 2626 | |
| 2627 </listitem> | |
| 2628 | |
| 2629 <listitem> | |
| 2630 | |
| 2631 <para> | |
| 2632 <literal>NGX_TERMINATE_SIGNAL</literal> (<literal>SIGTERM</literal>) - | |
| 2633 terminate. | |
| 2634 Upon receiving this signal master process sends terminate signal to all child | |
| 2635 processes. | |
| 2636 If child processes do not exit in 1 second, they are killed with the | |
| 2637 <literal>SIGKILL</literal> signal. | |
| 2638 When no child processes are left, master process destroys cycle pool and exits. | |
| 2639 A worker or cache manager process which received this signal destroys cycle | |
| 2640 pool and exits. | |
| 2641 The variable <literal>ngx_terminate</literal> is set to one after receiving | |
| 2642 this signal | |
| 2643 </para> | |
| 2644 | |
| 2645 | |
| 2646 </listitem> | |
| 2647 | |
| 2648 <listitem> | |
| 2649 | |
| 2650 <para> | |
| 2651 <literal>NGX_NOACCEPT_SIGNAL</literal> (<literal>SIGWINCH</literal>) | |
| 2652 - gracefully shut down worker processes | |
| 2653 </para> | |
| 2654 | |
| 2655 | |
| 2656 </listitem> | |
| 2657 | |
| 2658 <listitem> | |
| 2659 | |
| 2660 <para> | |
| 2661 <literal>NGX_RECONFIGURE_SIGNAL</literal> (<literal>SIGHUP</literal>) - | |
| 2662 reconfigure. | |
| 2663 Upon receiving this signal master process creates a new cycle from | |
| 2664 configuration file. | |
| 2665 If the new cycle was created successfully, the old cycle is deleted and new | |
| 2666 child processes are started. | |
| 2667 Meanwhile, the old processes receive the shutdown signal. | |
| 2668 In single-process mode, nginx creates a new cycle as well, but keeps the old | |
| 2669 one until all clients, tied to the old cycle, are gone. | |
| 2670 Worker and helper processes ignore this signal | |
| 2671 </para> | |
| 2672 | |
| 2673 | |
| 2674 </listitem> | |
| 2675 | |
| 2676 <listitem> | |
| 2677 | |
| 2678 <para> | |
|
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diff
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|
2679 <literal>NGX_REOPEN_SIGNAL</literal> (<literal>SIGUSR1</literal>) — reopen |
| 1899 | 2680 files. |
| 2681 Master process passes this signal to workers. | |
| 2682 Worker processes reopen all <literal>open_files</literal> from the cycle | |
| 2683 </para> | |
| 2684 | |
| 2685 | |
| 2686 </listitem> | |
| 2687 | |
| 2688 <listitem> | |
| 2689 | |
| 2690 <para> | |
|
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|
2691 <literal>NGX_CHANGEBIN_SIGNAL</literal> (<literal>SIGUSR2</literal>) — change |
| 1899 | 2692 nginx binary. |
| 2693 Master process starts a new nginx binary and passes there a list of all listen | |
| 2694 sockets. | |
|
1936
8f996938fe23
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|
2695 The list is passed in the environment variable <literal>“NGINX”</literal> in |
| 1899 | 2696 text format, where descriptor numbers separated with semicolons. |
| 2697 A new nginx instance reads that variable and adds the sockets to its init | |
| 2698 cycle. | |
| 2699 Other processes ignore this signal | |
| 2700 </para> | |
| 2701 | |
| 2702 | |
| 2703 </listitem> | |
| 2704 | |
| 2705 </list> | |
| 2706 | |
| 2707 <para> | |
| 2708 While all nginx worker processes are able to receive and properly handle POSIX | |
| 2709 signals, master process normally does not pass any signals to workers and | |
| 2710 helpers with the standard <literal>kill()</literal> syscall. | |
| 2711 Instead, nginx uses inter-process channels which allow sending messages between | |
| 2712 all nginx processes. | |
| 2713 Currently, however, messages are only sent from master to its children. | |
| 2714 Those messages carry the same signals. | |
| 2715 The channels are socketpairs with their ends in different processes. | |
| 2716 </para> | |
| 2717 | |
| 2718 <para> | |
| 2719 When running nginx binary, several values can be specified next to | |
| 2720 <literal>-s</literal> parameter. | |
| 2721 Those values are <literal>stop</literal>, <literal>quit</literal>, | |
| 2722 <literal>reopen</literal>, <literal>reload</literal>. | |
| 2723 They are converted to signals <literal>NGX_TERMINATE_SIGNAL</literal>, | |
| 2724 <literal>NGX_SHUTDOWN_SIGNAL</literal>, <literal>NGX_REOPEN_SIGNAL</literal> | |
| 2725 and <literal>NGX_RECONFIGURE_SIGNAL</literal> and sent to the nginx master | |
| 2726 process, whose pid is read from nginx pid file. | |
| 2727 </para> | |
| 2728 | |
| 2729 </section> | |
| 2730 | |
|
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|
2731 <section name="Modules" id="Modules"> |
|
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|
2732 |
|
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|
2733 <section name="Adding new modules" id="adding_new_modules"> |
|
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|
2734 <para> |
|
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|
2735 The standalone nginx module resides in a separate directory that contains |
|
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|
2736 at least two files: |
|
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|
2737 <literal>config</literal> and a file with the module source. |
|
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|
2738 The first file contains all information needed for nginx to integrate |
|
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diff
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|
2739 the module, for example: |
|
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|
2740 <programlisting> |
|
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|
2741 ngx_module_type=CORE |
|
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|
2742 ngx_module_name=ngx_foo_module |
|
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|
2743 ngx_module_srcs="$ngx_addon_dir/ngx_foo_module.c" |
|
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|
2744 |
|
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|
2745 . auto/module |
|
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|
2746 |
|
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|
2747 ngx_addon_name=$ngx_module_name |
|
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|
2748 </programlisting> |
|
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diff
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|
2749 The file is a POSIX shell script and it can set (or access) the |
|
2c14a16c61eb
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1920
diff
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|
2750 following variables: |
|
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|
2751 <list type="bullet"> |
|
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|
2752 |
|
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|
2753 <listitem> |
|
1935
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|
2754 <literal>ngx_module_type</literal> — the type of module to build. |
|
1928
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|
2755 Possible options are <literal>CORE</literal>, <literal>HTTP</literal>, |
|
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|
2756 <literal>HTTP_FILTER</literal>, <literal>HTTP_INIT_FILTER</literal>, |
|
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|
2757 <literal>HTTP_AUX_FILTER</literal>, <literal>MAIL</literal>, |
|
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|
2758 <literal>STREAM</literal>, or <literal>MISC</literal> |
|
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|
2759 </listitem> |
|
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changeset
|
2760 |
|
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|
2761 <listitem> |
|
1935
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|
2762 <literal>ngx_module_name</literal> — the name of the module. |
|
1928
2c14a16c61eb
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|
2763 A whitespace separated values list is accepted and may be used to build |
|
2c14a16c61eb
Added modules section to development guide.
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1920
diff
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|
2764 multiple modules from a single set of source files. |
|
2c14a16c61eb
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diff
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|
2765 The first name indicates the name of the output binary for a dynamic module. |
|
2c14a16c61eb
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diff
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|
2766 The names in this list should match the names used in the module. |
|
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1920
diff
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|
2767 </listitem> |
|
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diff
changeset
|
2768 |
|
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diff
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|
2769 <listitem> |
|
1935
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|
2770 <literal>ngx_addon_name</literal> — supplies the name of the module in the |
|
1928
2c14a16c61eb
Added modules section to development guide.
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diff
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|
2771 console output text of the configure script. |
|
2c14a16c61eb
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1920
diff
changeset
|
2772 </listitem> |
|
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diff
changeset
|
2773 |
|
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|
2774 <listitem> |
|
1935
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changeset
|
2775 <literal>ngx_module_srcs</literal> — a whitespace separated list of source |
|
1928
2c14a16c61eb
Added modules section to development guide.
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parents:
1920
diff
changeset
|
2776 files used to compile the module. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2777 The $ngx_addon_dir variable can be used as a placeholder for the path of the |
|
2c14a16c61eb
Added modules section to development guide.
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parents:
1920
diff
changeset
|
2778 module source. |
|
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parents:
1920
diff
changeset
|
2779 </listitem> |
|
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1920
diff
changeset
|
2780 |
|
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diff
changeset
|
2781 <listitem> |
|
1935
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diff
changeset
|
2782 <literal>ngx_module_incs</literal> — include paths required to build the module |
|
be7490a66d1b
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changeset
|
2783 </listitem> |
|
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diff
changeset
|
2784 |
|
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diff
changeset
|
2785 <listitem> |
|
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diff
changeset
|
2786 <literal>ngx_module_deps</literal> — a list of module's header files. |
|
be7490a66d1b
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changeset
|
2787 </listitem> |
|
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diff
changeset
|
2788 |
|
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diff
changeset
|
2789 <listitem> |
|
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parents:
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diff
changeset
|
2790 <literal>ngx_module_libs</literal> — a list of libraries to link with the |
|
1928
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diff
changeset
|
2791 module. |
|
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1920
diff
changeset
|
2792 For example, libpthread would be linked using |
|
2c14a16c61eb
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1920
diff
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|
2793 <literal>ngx_module_libs=-lpthread</literal>. |
|
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1920
diff
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|
2794 The following macros can be used to link against the same libraries as |
|
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1920
diff
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|
2795 nginx: |
|
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1920
diff
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|
2796 <literal>LIBXSLT</literal>, <literal>LIBGD</literal>, <literal>GEOIP</literal>, |
|
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diff
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|
2797 <literal>PCRE</literal>, <literal>OPENSSL</literal>, <literal>MD5</literal>, |
|
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diff
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|
2798 <literal>SHA1</literal>, <literal>ZLIB</literal>, and <literal>PERL</literal> |
|
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diff
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|
2799 </listitem> |
|
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diff
changeset
|
2800 |
|
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diff
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|
2801 <listitem> |
|
1935
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|
2802 <literal>ngx_module_link</literal> — set by the build system to |
|
1928
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diff
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|
2803 <literal>DYNAMIC</literal> for a dynamic module or <literal>ADDON</literal> |
|
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diff
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|
2804 for a static module and used to perform different actions depending on |
|
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diff
changeset
|
2805 linking type. |
|
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diff
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|
2806 </listitem> |
|
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diff
changeset
|
2807 |
|
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diff
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|
2808 <listitem> |
|
1935
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diff
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|
2809 <literal>ngx_module_order</literal> — sets the load order for the module which |
|
1928
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diff
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|
2810 is useful for <literal>HTTP_FILTER</literal> and |
|
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|
2811 <literal>HTTP_AUX_FILTER</literal> module types. |
|
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diff
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|
2812 The order is stored in a reverse list. |
|
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|
2813 |
|
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diff
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|
2814 <para> |
|
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diff
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|
2815 The <literal>ngx_http_copy_filter_module</literal> is near the bottom of the |
|
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diff
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|
2816 list so is one of the first to be executed. |
|
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diff
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|
2817 This reads the data for other filters. |
|
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diff
changeset
|
2818 Near the top of the list is <literal>ngx_http_write_filter_module</literal> |
|
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diff
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|
2819 which writes the data out and is one of the last to be executed. |
|
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|
2820 </para> |
|
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diff
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|
2821 |
|
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diff
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|
2822 <para> |
|
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diff
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|
2823 The format for this option is typically the current module’s name followed by |
|
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parents:
1920
diff
changeset
|
2824 a whitespace separated list of modules to insert before, and therefore execute |
|
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Added modules section to development guide.
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parents:
1920
diff
changeset
|
2825 after. |
|
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Added modules section to development guide.
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parents:
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diff
changeset
|
2826 The module will be inserted before the last module in the list that is found |
|
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Added modules section to development guide.
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parents:
1920
diff
changeset
|
2827 to be currently loaded. |
|
2c14a16c61eb
Added modules section to development guide.
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parents:
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diff
changeset
|
2828 </para> |
|
2c14a16c61eb
Added modules section to development guide.
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parents:
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diff
changeset
|
2829 |
|
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Added modules section to development guide.
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parents:
1920
diff
changeset
|
2830 <para> |
|
2c14a16c61eb
Added modules section to development guide.
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parents:
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diff
changeset
|
2831 By default for filter modules this is set to |
|
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Added modules section to development guide.
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parents:
1920
diff
changeset
|
2832 “<literal>ngx_http_copy_filter</literal>” which will insert the module before |
|
2c14a16c61eb
Added modules section to development guide.
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parents:
1920
diff
changeset
|
2833 the copy filter in the list and therefore will execute after the copy filter. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2834 For other module types the default is empty. |
|
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Added modules section to development guide.
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parents:
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diff
changeset
|
2835 </para> |
|
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Added modules section to development guide.
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parents:
1920
diff
changeset
|
2836 |
|
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Added modules section to development guide.
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parents:
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diff
changeset
|
2837 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
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parents:
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diff
changeset
|
2838 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2839 </list> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2840 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2841 A module can be added to nginx by means of the configure script using |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2842 <literal>--add-module=/path/to/module</literal> for static compilation and |
|
2c14a16c61eb
Added modules section to development guide.
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parents:
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diff
changeset
|
2843 <literal>--add-dynamic-module=/path/to/module</literal> for dynamic compilation. |
|
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parents:
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diff
changeset
|
2844 </para> |
|
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parents:
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diff
changeset
|
2845 |
|
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Added modules section to development guide.
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parents:
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diff
changeset
|
2846 </section> |
|
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Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2847 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2848 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2849 <section name="Core modules" id="core_modules"> |
|
2c14a16c61eb
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parents:
1920
diff
changeset
|
2850 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2851 <para> |
|
2c14a16c61eb
Added modules section to development guide.
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parents:
1920
diff
changeset
|
2852 Modules are building blocks of nginx, and most of its functionality is |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2853 implemented as modules. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2854 The module source file must contain a global variable of |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2855 <literal>ngx_module_t</literal> type which is defined as follows: |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2856 <programlisting> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2857 struct ngx_module_s { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2858 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2859 /* private part is omitted */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2860 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2861 void *ctx; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2862 ngx_command_t *commands; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2863 ngx_uint_t type; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2864 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2865 ngx_int_t (*init_master)(ngx_log_t *log); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2866 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2867 ngx_int_t (*init_module)(ngx_cycle_t *cycle); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2868 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2869 ngx_int_t (*init_process)(ngx_cycle_t *cycle); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2870 ngx_int_t (*init_thread)(ngx_cycle_t *cycle); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2871 void (*exit_thread)(ngx_cycle_t *cycle); |
|
2c14a16c61eb
Added modules section to development guide.
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parents:
1920
diff
changeset
|
2872 void (*exit_process)(ngx_cycle_t *cycle); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2873 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2874 void (*exit_master)(ngx_cycle_t *cycle); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2875 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2876 /* stubs for future extensions are omitted */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2877 }; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2878 </programlisting> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2879 The omitted private part includes module version, signature and is filled |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2880 using the predefined macro <literal>NGX_MODULE_V1</literal>. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2881 </para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2882 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2883 <para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2884 Each module keeps its private data in the <literal>ctx</literal> field, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2885 recognizes specific configuration directives, specified in the |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2886 <literal>commands</literal> array, and may be invoked at certain stages of |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2887 nginx lifecycle. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2888 The module lifecycle consists of the following events: |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2889 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2890 <list type="bullet"> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2891 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2892 <listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2893 Configuration directive handlers are called as they appear |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2894 in configuration files in the context of the master process |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2895 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2896 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2897 <listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2898 The <literal>init_module</literal> handler is called in the context of |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2899 the master process after the configuration is parsed successfully |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2900 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2901 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2902 <listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2903 The master process creates worker process(es) and |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2904 <literal>init_process</literal> handler is called in each of them |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2905 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2906 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2907 <listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2908 When a worker process receives the shutdown command from master, it invokes |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2909 the <literal>exit_process</literal> handler |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2910 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2911 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2912 <listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2913 The master process calls the <literal>exit_master</literal> handler before |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2914 exiting. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2915 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2916 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2917 </list> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2918 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2919 <note> |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2920 <literal>init_module</literal> handler may be called multiple times |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2921 in the master process if the configuration reload is requested. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2922 </note> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2923 |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2924 The <literal>init_master</literal>, <literal>init_thread</literal> and |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2925 <literal>exit_thread</literal> handlers are not implemented at the moment; |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2926 Threads in nginx are only used as supplementary I/O facility with its own |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2927 API and <literal>init_master</literal> handler looks unnecessary. |
|
2c14a16c61eb
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parents:
1920
diff
changeset
|
2928 </para> |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
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1920
diff
changeset
|
2929 |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
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1920
diff
changeset
|
2930 <para> |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
parents:
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diff
changeset
|
2931 The module <literal>type</literal> defines what exactly is stored in the |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
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diff
changeset
|
2932 <literal>ctx</literal> field. |
|
2c14a16c61eb
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diff
changeset
|
2933 There are several types of modules: |
|
2c14a16c61eb
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diff
changeset
|
2934 <list type="bullet"> |
|
2c14a16c61eb
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diff
changeset
|
2935 <listitem><literal>NGX_CORE_MODULE</literal></listitem> |
|
2c14a16c61eb
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diff
changeset
|
2936 <listitem><literal>NGX_EVENT_MODULE</literal></listitem> |
|
2c14a16c61eb
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diff
changeset
|
2937 <listitem><literal>NGX_HTTP_MODULE</literal></listitem> |
|
2c14a16c61eb
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diff
changeset
|
2938 <listitem><literal>NGX_MAIL_MODULE</literal></listitem> |
|
2c14a16c61eb
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diff
changeset
|
2939 <listitem><literal>NGX_STREAM_MODULE</literal></listitem> |
|
2c14a16c61eb
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diff
changeset
|
2940 </list> |
|
2c14a16c61eb
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Vladimir Homutov <vl@nginx.com>
parents:
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diff
changeset
|
2941 The <literal>NGX_CORE_MODULE</literal> is the most basic and thus the most |
|
2c14a16c61eb
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diff
changeset
|
2942 generic and most low-level type of module. Other module types are implemented |
|
2c14a16c61eb
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parents:
1920
diff
changeset
|
2943 on top of it and provide more convenient way to deal with corresponding |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2944 problem domains, like handling events or http requests. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2945 </para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2946 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2947 <para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2948 The examples of core modules are <literal>ngx_core_module</literal>, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2949 <literal>ngx_errlog_module</literal>, <literal>ngx_regex_module</literal>, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2950 <literal>ngx_thread_pool_module</literal>, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2951 <literal>ngx_openssl_module</literal> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2952 modules and, of course, http, stream, mail and event modules itself. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2953 The context of a core module is defined as: |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2954 <programlisting> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2955 typedef struct { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2956 ngx_str_t name; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2957 void *(*create_conf)(ngx_cycle_t *cycle); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2958 char *(*init_conf)(ngx_cycle_t *cycle, void *conf); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2959 } ngx_core_module_t; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2960 </programlisting> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2961 where the <literal>name</literal> is a string with a module name for |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2962 convenience, <literal>create_conf</literal> and <literal>init_conf</literal> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2963 are pointers to functions that create and initialize module configuration |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2964 correspondingly. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2965 For core modules, nginx will call <literal>create_conf</literal> before parsing |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2966 a new configuration and <literal>init_conf</literal> after all configuration |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2967 was parsed successfully. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2968 The typical <literal>create_conf</literal> function allocates memory for the |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2969 configuration and sets default values. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2970 The <literal>init_conf</literal> deals with known configuration and thus may |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2971 perform sanity checks and complete initialization. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2972 </para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2973 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2974 <para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2975 For example, the simplistic <literal>ngx_foo_module</literal> can look like |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2976 this: |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2977 <programlisting> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2978 /* |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2979 * Copyright (C) Author. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2980 */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2981 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2982 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2983 #include <ngx_config.h> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2984 #include <ngx_core.h> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2985 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2986 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2987 typedef struct { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2988 ngx_flag_t enable; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2989 } ngx_foo_conf_t; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2990 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2991 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2992 static void *ngx_foo_create_conf(ngx_cycle_t *cycle); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2993 static char *ngx_foo_init_conf(ngx_cycle_t *cycle, void *conf); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2994 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2995 static char *ngx_foo_enable(ngx_conf_t *cf, void *post, void *data); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2996 static ngx_conf_post_t ngx_foo_enable_post = { ngx_foo_enable }; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2997 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2998 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
2999 static ngx_command_t ngx_foo_commands[] = { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3000 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3001 { ngx_string("foo_enabled"), |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3002 NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_FLAG, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3003 ngx_conf_set_flag_slot, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3004 0, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3005 offsetof(ngx_foo_conf_t, enable), |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3006 &ngx_foo_enable_post }, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3007 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3008 ngx_null_command |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3009 }; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3010 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3011 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3012 static ngx_core_module_t ngx_foo_module_ctx = { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3013 ngx_string("foo"), |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3014 ngx_foo_create_conf, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3015 ngx_foo_init_conf |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3016 }; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3017 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3018 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3019 ngx_module_t ngx_foo_module = { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3020 NGX_MODULE_V1, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3021 &ngx_foo_module_ctx, /* module context */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3022 ngx_foo_commands, /* module directives */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3023 NGX_CORE_MODULE, /* module type */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3024 NULL, /* init master */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3025 NULL, /* init module */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3026 NULL, /* init process */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3027 NULL, /* init thread */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3028 NULL, /* exit thread */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3029 NULL, /* exit process */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3030 NULL, /* exit master */ |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3031 NGX_MODULE_V1_PADDING |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3032 }; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3033 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3034 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3035 static void * |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
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diff
changeset
|
3036 ngx_foo_create_conf(ngx_cycle_t *cycle) |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
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diff
changeset
|
3037 { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3038 ngx_foo_conf_t *fcf; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3039 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
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1920
diff
changeset
|
3040 fcf = ngx_pcalloc(cycle->pool, sizeof(ngx_foo_conf_t)); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3041 if (fcf == NULL) { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3042 return NULL; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3043 } |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
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diff
changeset
|
3044 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
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1920
diff
changeset
|
3045 fcf->enable = NGX_CONF_UNSET; |
|
2c14a16c61eb
Added modules section to development guide.
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diff
changeset
|
3046 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3047 return fcf; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3048 } |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3049 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3050 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
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diff
changeset
|
3051 static char * |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
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diff
changeset
|
3052 ngx_foo_init_conf(ngx_cycle_t *cycle, void *conf) |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
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diff
changeset
|
3053 { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3054 ngx_foo_conf_t *fcf = conf; |
|
2c14a16c61eb
Added modules section to development guide.
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diff
changeset
|
3055 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
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diff
changeset
|
3056 ngx_conf_init_value(fcf->enable, 0); |
|
2c14a16c61eb
Added modules section to development guide.
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diff
changeset
|
3057 |
|
2c14a16c61eb
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diff
changeset
|
3058 return NGX_CONF_OK; |
|
2c14a16c61eb
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diff
changeset
|
3059 } |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3060 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3061 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3062 static char * |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3063 ngx_foo_enable(ngx_conf_t *cf, void *post, void *data) |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
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diff
changeset
|
3064 { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3065 ngx_flag_t *fp = data; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3066 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3067 if (*fp == 0) { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3068 return NGX_CONF_OK; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3069 } |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3070 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3071 ngx_log_error(NGX_LOG_NOTICE, cf->log, 0, "Foo Module is enabled"); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3072 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3073 return NGX_CONF_OK; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3074 } |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3075 </programlisting> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3076 </para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3077 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3078 </section> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3079 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3080 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3081 <section name="Configuration directives" id="config_directives"> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3082 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3083 <para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3084 The <literal>ngx_command_t</literal> describes single configuration directive. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3085 Each module, supporting configuration, provides an array of such specifications |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3086 that describe how to process arguments and what handlers to call: |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3087 <programlisting> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3088 struct ngx_command_s { |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3089 ngx_str_t name; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3090 ngx_uint_t type; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3091 char *(*set)(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3092 ngx_uint_t conf; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3093 ngx_uint_t offset; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3094 void *post; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3095 }; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3096 </programlisting> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3097 The array should be terminated by a special value |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3098 “<literal>ngx_null_command</literal>”. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3099 The <literal>name</literal> is the literal name of a directive, as it appears |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3100 in configuration file, for example “<literal>worker_processes</literal>” or |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3101 “<literal>listen</literal>”. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3102 The <literal>type</literal> is a bitfield that controls number of arguments, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3103 command type and other properties using corresponding flags. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3104 Arguments flags: |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3105 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3106 <list type="bullet"> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3107 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3108 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3109 <literal>NGX_CONF_NOARGS</literal> — directive without arguments |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3110 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3111 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3112 <listitem><literal>NGX_CONF_1MORE</literal> — one required argument</listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3113 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3114 <listitem><literal>NGX_CONF_2MORE</literal> — two required arguments</listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3115 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3116 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3117 <literal>NGX_CONF_TAKE1..7</literal> — exactly 1..7 arguments |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3118 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3119 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3120 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3121 <literal>NGX_CONF_TAKE12, 13, 23, 123, 1234</literal> — one or two arguments, |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3122 or other combinations |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3123 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3124 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3125 </list> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3126 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3127 Directive types: |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3128 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3129 <list type="bullet"> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3130 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3131 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3132 <literal>NGX_CONF_BLOCK</literal> — the directive is a block, i.e. it may |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3133 contain other directives in curly braces, or even implement its own parser |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3134 to handle contents inside. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3135 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3136 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3137 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3138 <literal>NGX_CONF_FLAG</literal> — the directive value is a flag, a boolean |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3139 value represented by “<literal>on</literal>” or “<literal>off</literal>” |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3140 strings. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3141 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3142 </list> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3143 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3144 Context of a directive defines where in the configuration it may appear |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3145 and how to access module context to store corresponding values: |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3146 <list type="bullet"> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3147 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3148 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3149 <literal>NGX_MAIN_CONF</literal> — top level configuration |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3150 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3151 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3152 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3153 <literal>NGX_HTTP_MAIN_CONF</literal> — in the http block |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3154 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3155 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3156 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3157 <literal>NGX_HTTP_SRV_CONF</literal> — in the http server block |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3158 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3159 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3160 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3161 <literal>NGX_HTTP_LOC_CONF</literal> — in the http location |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3162 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3163 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3164 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3165 <literal>NGX_HTTP_UPS_CONF</literal> — in the http upstream block |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3166 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3167 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3168 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3169 <literal>NGX_HTTP_SIF_CONF</literal> — in the http server “if” |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3170 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3171 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3172 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3173 <literal>NGX_HTTP_LIF_CONF</literal> — in the http location “if” |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3174 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3175 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3176 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3177 <literal>NGX_HTTP_LMT_CONF</literal> — in the http “limit_except” |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3178 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3179 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3180 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3181 <literal>NGX_STREAM_MAIN_CONF</literal> — in the stream block |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3182 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3183 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3184 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3185 <literal>NGX_STREAM_SRV_CONF</literal> — in the stream server block |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3186 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3187 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3188 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3189 <literal>NGX_STREAM_UPS_CONF</literal> — in the stream upstream block |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3190 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3191 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3192 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3193 <literal>NGX_MAIL_MAIN_CONF</literal> — in the the mail block |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3194 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3195 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3196 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3197 <literal>NGX_MAIL_SRV_CONF</literal> — in the mail server block |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3198 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3199 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3200 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3201 <literal>NGX_EVENT_CONF</literal> — in the event block |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3202 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3203 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3204 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3205 <literal>NGX_DIRECT_CONF</literal> — used by modules that don't |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3206 create a hierarchy of contexts and store module configuration directly in ctx |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3207 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3208 </list> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3209 The configuration parser uses this flags to throw an error in case of |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3210 a misplaced directive and calls directive handlers supplied with a proper |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3211 configuration pointer, so that same directives in different locations could |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3212 store their values in distinct places. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3213 </para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3214 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3215 <para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3216 The <literal>set</literal> field defines a handler that processes a directive |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3217 and stores parsed values into corresponding configuration. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3218 Nginx offers a convenient set of functions that perform common conversions: |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3219 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3220 <list type="bullet"> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3221 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3222 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3223 <literal>ngx_conf_set_flag_slot</literal> — converts literal |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3224 “<literal>on</literal>” or “<literal>off</literal>” strings into |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3225 <literal>ngx_flag_t</literal> type with values 1 or 0 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3226 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3227 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3228 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3229 <literal>ngx_conf_set_str_slot</literal> — stores string as a value of the |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3230 <literal>ngx_str_t</literal> type |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3231 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3232 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3233 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3234 <literal>ngx_conf_set_str_array_slot</literal> — appends |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3235 <literal>ngx_array_t</literal> of <literal>ngx_str_t</literal> with a new value. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3236 The array is created if not yet exists |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3237 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3238 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3239 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3240 <literal>ngx_conf_set_keyval_slot</literal> — appends |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3241 <literal>ngx_array_t</literal> of <literal>ngx_keyval_t</literal> with |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3242 a new value, where key is the first string and value is second. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3243 The array is created if not yet exists |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3244 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3245 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3246 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3247 <literal>ngx_conf_set_num_slot</literal> — converts directive argument |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3248 to a <literal>ngx_int_t</literal> value |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3249 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3250 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3251 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3252 <literal>ngx_conf_set_size_slot</literal> — converts |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3253 <link doc="../syntax.xml">size</link> to <literal>size_t</literal> value |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3254 in bytes |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3255 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3256 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3257 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3258 <literal>ngx_conf_set_off_slot</literal> — converts |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3259 <link doc="../syntax.xml">offset</link> to <literal>off_t</literal> value |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3260 in bytes |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3261 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3262 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3263 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3264 <literal>ngx_conf_set_msec_slot</literal> — converts |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3265 <link doc="../syntax.xml">time</link> to <literal>ngx_msec_t</literal> value |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3266 in milliseconds |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3267 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3268 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3269 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3270 <literal>ngx_conf_set_sec_slot</literal> — converts |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3271 <link doc="../syntax.xml">time</link> to <literal>time_t</literal> value |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3272 in seconds |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3273 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3274 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3275 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3276 <literal>ngx_conf_set_bufs_slot</literal> — converts two arguments |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3277 into <literal>ngx_bufs_t</literal> that holds <literal>ngx_int_t</literal> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3278 number and <link doc="../syntax.xml">size</link> of buffers |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3279 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3280 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3281 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3282 <literal>ngx_conf_set_enum_slot</literal> — converts argument |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3283 into <literal>ngx_uint_t</literal> value. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3284 The null-terminated array of <literal>ngx_conf_enum_t</literal> passed in the |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3285 <literal>post</literal> field defines acceptable strings and corresponding |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3286 integer values |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3287 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3288 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3289 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3290 <literal>ngx_conf_set_bitmask_slot</literal> — arguments are converted to |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3291 <literal>ngx_uint_t</literal> value and OR'ed with the resulting value, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3292 forming a bitmask. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3293 The null-terminated array of <literal>ngx_conf_bitmask_t</literal> passed in |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3294 the <literal>post</literal> field defines acceptable strings and corresponding |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3295 mask values |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3296 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3297 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3298 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3299 <literal>set_path_slot</literal> — converts arguments to |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3300 <literal>ngx_path_t</literal> type and performs all required initializations. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3301 See the |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3302 <link doc="../http/ngx_http_proxy_module.xml" id="proxy_temp_path">proxy_temp_path</link> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3303 directive description for details |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3304 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3305 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3306 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3307 <literal>set_access_slot</literal> — converts arguments to file permissions |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3308 mask. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3309 See the |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3310 <link doc="../http/ngx_http_proxy_module.xml" id="proxy_store_access">proxy_store_access</link> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3311 directive description for details |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3312 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3313 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3314 </list> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3315 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3316 </para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3317 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3318 <para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3319 The <literal>conf</literal> field defines which context is used to store |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3320 the value of the directive, or zero if contexts are not used. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3321 Only simple core modules use configuration without context and set |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3322 <literal>NGX_DIRECT_CONF</literal> flag. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3323 In real life, such modules like http or stream require more sophisticated |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3324 configuration that can be applied per-server or per-location, or even more |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3325 precisely, in the context of the “<literal>if</literal>” directive or |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3326 some limit. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3327 In this modules, configuration structure is more complex. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3328 Please refer to corresponding modules description to understand how |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3329 they manage their configuration. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3330 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3331 <list type="bullet"> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3332 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3333 <literal>NGX_HTTP_MAIN_CONF_OFFSET</literal> — http block configuration |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3334 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3335 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3336 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3337 <literal>NGX_HTTP_SRV_CONF_OFFSET</literal> — http server configuration |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3338 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3339 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3340 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3341 <literal>NGX_HTTP_LOC_CONF_OFFSET</literal> — http location configuration |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3342 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3343 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3344 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3345 <literal>NGX_STREAM_MAIN_CONF_OFFSET</literal> — stream block configuration |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3346 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3347 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3348 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3349 <literal>NGX_STREAM_SRV_CONF_OFFSET</literal> — stream server configuration |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3350 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3351 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3352 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3353 <literal>NGX_MAIL_MAIN_CONF_OFFSET</literal> — mail block configuration |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3354 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3355 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3356 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3357 <literal>NGX_MAIL_SRV_CONF_OFFSET</literal> — mail server configuration |
|
1928
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3358 </listitem> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3359 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3360 </list> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3361 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3362 </para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3363 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3364 <para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3365 The <literal>offset</literal> defines an offset of a field in a module |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3366 configuration structure that holds values of this particular directive. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3367 The typical use is to employ <literal>offsetof()</literal> macro. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3368 </para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3369 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3370 <para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3371 The <literal>post</literal> is a twofold field: it may be used to define |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3372 a handler to be called after main handler completed or to pass additional |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3373 data to the main handler. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3374 In the first case, <literal>ngx_conf_post_t</literal> structure needs to |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3375 be initialized with a pointer to handler, for example: |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3376 <programlisting> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3377 static char *ngx_do_foo(ngx_conf_t *cf, void *post, void *data); |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3378 static ngx_conf_post_t ngx_foo_post = { ngx_do_foo }; |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3379 </programlisting> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3380 The <literal>post</literal> argument is the <literal>ngx_conf_post_t</literal> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3381 object itself, and the <literal>data</literal> is a pointer to value, |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3382 converted from arguments by the main handler with the appropriate type. |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3383 </para> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3384 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3385 </section> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3386 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3387 </section> |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3388 |
|
2c14a16c61eb
Added modules section to development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1920
diff
changeset
|
3389 |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3390 <section name="HTTP" id="http"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3391 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3392 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3393 <section name="Connection" id="http_connection"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3394 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3395 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3396 Each client HTTP connection runs through the following stages: |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3397 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3398 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3399 <list type="bullet"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3400 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3401 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3402 <literal>ngx_event_accept()</literal> accepts a client TCP connection. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3403 This handler is called in response to a read notification on a listen socket. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3404 A new <literal>ngx_connecton_t</literal> object is created at this stage. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3405 The object wraps the newly accepted client socket. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3406 Each nginx listener provides a handler to pass the new connection object to. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3407 For HTTP connections it's <literal>ngx_http_init_connection(c)</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3408 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3409 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3410 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3411 <literal>ngx_http_init_connection()</literal> performs early initialization of |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3412 an HTTP connection. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
3413 At this stage an <literal>ngx_http_connection_t</literal> object is created for |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3414 the connection and its reference is stored in connection's |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3415 <literal>data</literal> field. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3416 Later it will be substituted with an HTTP request object. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3417 PROXY protocol parser and SSL handshake are started at this stage as well |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3418 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3419 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3420 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3421 <literal>ngx_http_wait_request_handler()</literal> is a read event handler, that |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3422 is called when data is available in the client socket. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3423 At this stage an HTTP request object <literal>ngx_http_request_t</literal> is |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3424 created and set to connection's <literal>data</literal> field |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3425 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3426 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3427 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3428 <literal>ngx_http_process_request_line()</literal> is a read event handler, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3429 which reads client request line. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3430 The handler is set by <literal>ngx_http_wait_request_handler()</literal>. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3431 Reading is done into connection's <literal>buffer</literal>. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3432 The size of the buffer is initially set by the directive |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3433 <link doc="../http/ngx_http_core_module.xml" id="client_header_buffer_size"/>. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3434 The entire client header is supposed to fit the buffer. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3435 If the initial size is not enough, a bigger buffer is allocated, whose size is |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3436 set by the <literal>large_client_header_buffers</literal> directive |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3437 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3438 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3439 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3440 <literal>ngx_http_process_request_headers()</literal> is a read event handler, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3441 which is set after <literal>ngx_http_process_request_line()</literal> to read |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3442 client request header |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3443 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3444 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3445 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3446 <literal>ngx_http_core_run_phases()</literal> is called when the request header |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3447 is completely read and parsed. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3448 This function runs request phases from |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3449 <literal>NGX_HTTP_POST_READ_PHASE</literal> to |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3450 <literal>NGX_HTTP_CONTENT_PHASE</literal>. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3451 The last phase is supposed to generate response and pass it along the filter |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3452 chain. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3453 The response in not necessarily sent to the client at this phase. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3454 It may remain buffered and will be sent at the finalization stage |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3455 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3456 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3457 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3458 <literal>ngx_http_finalize_request()</literal> is usually called when the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3459 request has generated all the output or produced an error. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3460 In the latter case an appropriate error page is looked up and used as the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3461 response. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3462 If the response is not completely sent to the client by this point, an |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3463 HTTP writer <literal>ngx_http_writer()</literal> is activated to finish |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3464 sending outstanding data |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3465 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3466 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3467 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3468 <literal>ngx_http_finalize_connection()</literal> is called when the response is |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3469 completely sent to the client and the request can be destroyed. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3470 If client connection keepalive feature is enabled, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3471 <literal>ngx_http_set_keepalive()</literal> is called, which destroys current |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3472 request and waits for the next request on the connection. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3473 Otherwise, <literal>ngx_http_close_request()</literal> destroys both the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3474 request and the connection |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3475 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3476 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3477 </list> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3478 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3479 </section> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3480 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3481 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3482 <section name="Request" id="http_request"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3483 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3484 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3485 For each client HTTP request the <literal>ngx_http_request_t</literal> object is |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3486 created. Some of the fields of this object: |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3487 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3488 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3489 <list type="bullet"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3490 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3491 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3492 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3493 <para> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3494 <literal>connection</literal> — pointer to a <literal>ngx_connection_t</literal> |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3495 client connection object. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3496 Several requests may reference the same connection object at the same time - |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3497 one main request and its subrequests. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3498 After a request is deleted, a new request may be created on the same connection. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3499 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3500 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3501 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3502 Note that for HTTP connections <literal>ngx_connection_t</literal>'s |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3503 <literal>data</literal> field points back to the request. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3504 Such request is called active, as opposed to the other requests tied with the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3505 connection. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3506 Active request is used to handle client connection events and is allowed to |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3507 output its response to the client. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3508 Normally, each request becomes active at some point to be able to send its |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3509 output |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3510 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3511 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3512 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3513 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3514 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3515 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3516 <para> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3517 <literal>ctx</literal> — array of HTTP module contexts. |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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1928
diff
changeset
|
3518 Each module of type <literal>NGX_HTTP_MODULE</literal> can store any value |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3519 (normally, a pointer to a structure) in the request. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3520 The value is stored in the <literal>ctx</literal> array at the module's |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3521 <literal>ctx_index</literal> position. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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1928
diff
changeset
|
3522 The following macros provide a convenient way to get and set request contexts: |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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1928
diff
changeset
|
3523 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3524 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3525 <list type="bullet"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3526 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3527 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3528 <literal>ngx_http_get_module_ctx(r, module)</literal> — returns |
|
1929
7f290929b32d
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Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3529 <literal>module</literal>'s context |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3530 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3531 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3532 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3533 <literal>ngx_http_set_ctx(r, c, module)</literal> — sets <literal>c</literal> |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3534 as <literal>module</literal>'s context |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3535 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3536 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3537 </list> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3538 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3539 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3540 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3541 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3542 <literal>main_conf, srv_conf, loc_conf</literal> — arrays of current request |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3543 configurations. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3544 Configurations are stored at module's <literal>ctx_index</literal> positions |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3545 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3546 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3547 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3548 <literal>read_event_handler</literal>, <literal>write_event_handler</literal> - |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3549 read and write event handlers for the request. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3550 Normally, an HTTP connection has <literal>ngx_http_request_handler()</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3551 set as both read and write event handlers. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3552 This function calls <literal>read_event_handler</literal> and |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3553 <literal>write_event_handler</literal> handlers of the currently active request |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3554 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3555 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3556 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3557 <literal>cache</literal> — request cache object for caching upstream response |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3558 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3559 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3560 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3561 <literal>upstream</literal> — request upstream object for proxying |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3562 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3563 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3564 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3565 <literal>pool</literal> — request pool. |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3566 This pool is destroyed when the request is deleted. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3567 The request object itself is allocated in this pool. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3568 For allocations which should be available throughout the client connection's |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3569 lifetime, <literal>ngx_connection_t</literal>'s pool should be used instead |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3570 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3571 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3572 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3573 <literal>header_in</literal> — buffer where client HTTP request header in read |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3574 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3575 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3576 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3577 <literal>headers_in, headers_out</literal> — input and output HTTP headers |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3578 objects. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3579 Both objects contain the <literal>headers</literal> field of type |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3580 <literal>ngx_list_t</literal> keeping the raw list of headers. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3581 In addition to that, specific headers are available for getting and setting as |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3582 separate fields, for example <literal>content_length_n</literal>, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3583 <literal>status</literal> etc |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3584 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3585 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3586 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3587 <literal>request_body</literal> — client request body object |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3588 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3589 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3590 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3591 <literal>start_sec, start_msec</literal> — time point when the request was |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3592 created. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3593 Used for tracking request duration |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3594 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3595 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3596 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3597 <literal>method, method_name</literal> — numeric and textual representation of |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3598 client HTTP request method. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3599 Numeric values for methods are defined in |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3600 <literal>src/http/ngx_http_request.h</literal> with macros |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3601 <literal>NGX_HTTP_GET, NGX_HTTP_HEAD, NGX_HTTP_POST</literal> etc |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3602 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3603 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3604 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3605 <literal>http_protocol, http_version, http_major, http_minor</literal> - |
|
1936
8f996938fe23
Style: proper quotes usage.
Vladimir Homutov <vl@nginx.com>
parents:
1935
diff
changeset
|
3606 client HTTP protocol version in its original textual form (“HTTP/1.0”, |
|
8f996938fe23
Style: proper quotes usage.
Vladimir Homutov <vl@nginx.com>
parents:
1935
diff
changeset
|
3607 “HTTP/1.1” etc), numeric form (<literal>NGX_HTTP_VERSION_10</literal>, |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3608 <literal>NGX_HTTP_VERSION_11</literal> etc) and separate major and minor |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3609 versions |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3610 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3611 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3612 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3613 <literal>request_line, unparsed_uri</literal> — client original request line |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3614 and URI |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3615 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3616 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3617 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3618 <literal>uri, args, exten</literal> — current request URI, arguments and file |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3619 extention. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3620 The URI value here might differ from the original URI sent by the client due to |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3621 normalization. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3622 Throughout request processing, these value can change while performing internal |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3623 redirects |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3624 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3625 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3626 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3627 <literal>main</literal> — pointer to a main request object. |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3628 This object is created to process client HTTP request, as opposed to |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3629 subrequests, created to perform a specific sub-task within the main request |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3630 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3631 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3632 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3633 <literal>parent</literal> — pointer to a parent request of a subrequest |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3634 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3635 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3636 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3637 <literal>postponed</literal> — list of output buffers and subrequests in the |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3638 order they are sent and created. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3639 The list is used by the postpone filter to provide consistent request output, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3640 when parts of it are created by subrequests |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3641 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3642 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3643 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3644 <literal>post_subrequest</literal> — pointer to a handler with context to be |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3645 called when a subrequest gets finalized. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3646 Unused for main requests |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3647 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3648 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3649 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3650 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3651 <para> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3652 <literal>posted_requests</literal> — list of requests to be started or |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3653 resumed. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3654 Starting or resuming is done by calling the request's |
| 1932 | 3655 <literal>write_event_handler</literal>. |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3656 Normally, this handler holds the request main function, which at first runs |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3657 request phases and then produces the output. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3658 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3659 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3660 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3661 A request is usually posted by the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3662 <literal>ngx_http_post_request(r, NULL)</literal> call. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3663 It is always posted to the main request <literal>posted_requests</literal> list. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3664 The function <literal>ngx_http_run_posted_requests(c)</literal> runs all |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3665 requests, posted in the main request of the passed connection's active request. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3666 This function should be called in all event handlers, which can lead to new |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3667 posted requests. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3668 Normally, it's called always after invoking a request's read or write handler |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3669 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3670 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3671 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3672 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3673 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3674 <literal>phase_handler</literal> — index of current request phase |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3675 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3676 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3677 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3678 <literal>ncaptures, captures, captures_data</literal> — regex captures produced |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3679 by the last regex match of the request. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3680 While processing a request, there's a number of places where a regex match can |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3681 happen: map lookup, server lookup by SNI or HTTP Host, rewrite, proxy_redirect |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3682 etc. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3683 Captures produced by a lookup are stored in the above mentioned fields. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3684 The field <literal>ncaptures</literal> holds the number of captures, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3685 <literal>captures</literal> holds captures boundaries, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3686 <literal>captures_data</literal> holds a string, against which the regex was |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3687 matched and which should be used to extract captures. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3688 After each new regex match request captures are reset to hold new values |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3689 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3690 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3691 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3692 <literal>count</literal> — request reference counter. |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3693 The field only makes sense for the main request. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3694 Increasing the counter is done by simple <literal>r->main->count++</literal>. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3695 To decrease the counter <literal>ngx_http_finalize_request(r, rc)</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3696 should be called. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3697 Creation of a subrequest or running request body read process increase the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3698 counter |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3699 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3700 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3701 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3702 <literal>subrequests</literal> — current subrequest nesting level. |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3703 Each subrequest gets the nesting level of its parent decreased by one. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3704 Once the value reaches zero an error is generated. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3705 The value for the main request is defined by the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3706 <literal>NGX_HTTP_MAX_SUBREQUESTS</literal> constant |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3707 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3708 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3709 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3710 <literal>uri_changes</literal> — number of URI changes left for the request. |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3711 The total number of times a request can change its URI is limited by the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3712 <literal>NGX_HTTP_MAX_URI_CHANGES</literal> constant. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3713 With each change the value is decreased until it reaches zero. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3714 In the latter case an error is generated. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3715 The actions considered as URI changes are rewrites and internal redirects to |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3716 normal or named locations |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3717 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3718 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3719 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3720 <literal>blocked</literal> — counter of blocks held on the request. |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3721 While this value is non-zero, request cannot be terminated. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3722 Currently, this value is increased by pending AIO operations (POSIX AIO and |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3723 thread operations) and active cache lock |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3724 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3725 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3726 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3727 <literal>buffered</literal> — bitmask showing which modules have buffered the |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3728 output produced by the request. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3729 A number of filters can buffer output, for example sub_filter can buffer data |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3730 due to a partial string match, copy filter can buffer data because of the lack |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3731 of free output_buffers etc. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3732 As long as this value is non-zero, request is not finalized, expecting the flush |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3733 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3734 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3735 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3736 <literal>header_only</literal> — flag showing that output does not require body. |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3737 For example, this flag is used by HTTP HEAD requests |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3738 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3739 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3740 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3741 <para> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3742 <literal>keepalive</literal> — flag showing if client connection keepalive is |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3743 supported. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3744 The value is inferred from HTTP version and <header>Connection</header> header |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3745 value |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3746 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3747 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3748 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3749 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3750 <literal>header_sent</literal> — flag showing that output header has already |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3751 been sent by the request |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3752 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3753 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3754 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3755 <literal>internal</literal> — flag showing that current request is internal. |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3756 To enter the internal state, a request should pass through an internal |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3757 redirect or be a subrequest. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3758 Internal requests are allowed to enter internal locations |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3759 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3760 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3761 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3762 <literal>allow_ranges</literal> — flag showing that partial response can be |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3763 sent to client, if requested by the HTTP Range header |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3764 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3765 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3766 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3767 <literal>subrequest_ranges</literal> — flag showing that a partial response is |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3768 allowed to be sent while processing a subrequest |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3769 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3770 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3771 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3772 <literal>single_range</literal> — flag showing that only a single continuous |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3773 range of output data can be sent to the client. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3774 This flag is usually set when sending a stream of data, for example from a |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3775 proxied server, and the entire response is not available at once |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3776 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3777 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3778 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3779 <literal>main_filter_need_in_memory, filter_need_in_memory</literal> — flags |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3780 showing that the output should be produced in memory buffers but not in files. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3781 This is a signal to the copy filter to read data from file buffers even if |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3782 sendfile is enabled. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3783 The difference between these two flags is the location of filter modules which |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3784 set them. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3785 Filters called before the postpone filter in filter chain, set |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3786 <literal>filter_need_in_memory</literal> requesting that only the current |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3787 request output should come in memory buffers. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3788 Filters called later in filter chain set |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3789 <literal>main_filter_need_in_memory</literal> requiring that both the main |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3790 request and all the subrequest read files in memory while sending output |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3791 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3792 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3793 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
3794 <literal>filter_need_temporary</literal> — flag showing that the request output |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3795 should be produced in temporary buffers, but not in readonly memory buffers or |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3796 file buffers. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3797 This is used by filters which may change output directly in the buffers, where |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3798 it's sent </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3799 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3800 </list> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3801 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3802 </section> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3803 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3804 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3805 <section name="Configuration" id="http_conf"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3806 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3807 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3808 Each HTTP module may have three types of configuration: |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3809 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3810 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3811 <list type="bullet"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3812 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3813 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3814 Main configuration. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3815 This configuration applies to the entire nginx http{} block. This is global |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3816 configuration. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3817 It stores global settings for a module |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3818 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3819 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3820 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3821 Server configuration. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3822 This configuraion applies to a single nginx server{}. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3823 It stores server-specific settings for a module |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3824 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3825 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3826 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3827 Location configuration. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3828 This configuraion applies to a single location{}, if{} or limit_except() block. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3829 This configuration stores settings specific to a location |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3830 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3831 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3832 </list> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3833 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3834 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3835 Configuration structures are created at nginx configuration stage by calling |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3836 functions, which allocate these structures, initialize them and merge. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3837 The following example shows how to create a simple module location |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3838 configuration. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3839 The configuration has one setting <literal>foo</literal> of unsiged integer |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3840 type. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3841 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3842 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3843 <programlisting> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3844 typedef struct { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3845 ngx_uint_t foo; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3846 } ngx_http_foo_loc_conf_t; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3847 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3848 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3849 static ngx_http_module_t ngx_http_foo_module_ctx = { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3850 NULL, /* preconfiguration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3851 NULL, /* postconfiguration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3852 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3853 NULL, /* create main configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3854 NULL, /* init main configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3855 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3856 NULL, /* create server configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3857 NULL, /* merge server configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3858 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3859 ngx_http_foo_create_loc_conf, /* create location configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3860 ngx_http_foo_merge_loc_conf /* merge location configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3861 }; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3862 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3863 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3864 static void * |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3865 ngx_http_foo_create_loc_conf(ngx_conf_t *cf) |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3866 { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3867 ngx_http_foo_loc_conf_t *conf; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3868 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3869 conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_foo_loc_conf_t)); |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3870 if (conf == NULL) { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3871 return NULL; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3872 } |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3873 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3874 conf->foo = NGX_CONF_UNSET_UINT; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3875 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3876 return conf; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3877 } |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3878 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3879 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3880 static char * |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3881 ngx_http_foo_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3882 { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3883 ngx_http_foo_loc_conf_t *prev = parent; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3884 ngx_http_foo_loc_conf_t *conf = child; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3885 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3886 ngx_conf_merge_uint_value(conf->foo, prev->foo, 1); |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3887 } |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3888 </programlisting> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3889 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3890 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3891 As seen in the example, <literal>ngx_http_foo_create_loc_conf()</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3892 function creates a new configuration structure and |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3893 <literal>ngx_http_foo_merge_loc_conf()</literal> merges a configuration with |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3894 another configuration from a higher level. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3895 In fact, server and location configuration do not only exist at server and |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3896 location levels, but also created for all the levels above. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3897 Specifically, a server configuration is created at the main level as well and |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3898 location configurations are created for main, server and location levels. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3899 These configurations make it possible to specify server and location-specific |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3900 settings at any level of nginx configuration file. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3901 Eventually configurations are merged down. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3902 To indicate a missing setting and ignore it while merging, nginx provides a |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3903 number of macros like <literal>NGX_CONF_UNSET</literal> and |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3904 <literal>NGX_CONF_UNSET_UINT</literal>. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3905 Standard nginx merge macros like <literal>ngx_conf_merge_value()</literal> and |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3906 <literal>ngx_conf_merge_uint_value()</literal> provide a convenient way to |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3907 merge a setting and set the default value if none of configurations provided an |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3908 explicit value. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3909 For complete list of macros for different types see |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3910 <literal>src/core/ngx_conf_file.h</literal>. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3911 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3912 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3913 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3914 To access configuration of any HTTP module at configuration time, the following |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3915 macros are available. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3916 They receive <literal>ngx_conf_t</literal> reference as the first argument. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3917 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3918 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3919 <list type="bullet"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3920 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3921 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3922 <literal>ngx_http_conf_get_module_main_conf(cf, module)</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3923 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3924 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3925 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3926 <literal>ngx_http_conf_get_module_srv_conf(cf, module)</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3927 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3928 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3929 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3930 <literal>ngx_http_conf_get_module_loc_conf(cf, module)</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3931 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3932 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3933 </list> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3934 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3935 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3936 The following example gets a pointer to a location configuration of |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3937 standard nginx core module |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3938 <link doc="../http/ngx_http_core_module.xml">ngx_http_core_module</link> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3939 and changes |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3940 location content handler kept in the <literal>handler</literal> field of the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3941 structure. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3942 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3943 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3944 <programlisting> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3945 static ngx_int_t ngx_http_foo_handler(ngx_http_request_t *r); |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3946 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3947 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3948 static ngx_command_t ngx_http_foo_commands[] = { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3949 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3950 { ngx_string("foo"), |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3951 NGX_HTTP_LOC_CONF|NGX_CONF_NOARGS, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3952 ngx_http_foo, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3953 0, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3954 0, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3955 NULL }, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3956 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3957 ngx_null_command |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3958 }; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3959 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3960 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3961 static char * |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3962 ngx_http_foo(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3963 { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3964 ngx_http_core_loc_conf_t *clcf; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3965 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3966 clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module); |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
3967 clcf->handler = ngx_http_bar_handler; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3968 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3969 return NGX_CONF_OK; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3970 } |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3971 </programlisting> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3972 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3973 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3974 In runtime the following macros are available to get configurations of HTTP |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3975 modules. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3976 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3977 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3978 <list type="bullet"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3979 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3980 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3981 <literal>ngx_http_get_module_main_conf(r, module)</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3982 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3983 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3984 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3985 <literal>ngx_http_get_module_srv_conf(r, module)</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3986 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3987 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3988 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3989 <literal>ngx_http_get_module_loc_conf(r, module)</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3990 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3991 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3992 </list> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3993 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3994 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3995 These macros receive a reference to an HTTP request |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3996 <literal>ngx_http_request_t</literal>. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
3997 Main configuration of a request never changes. |
|
7f290929b32d
HTTP section of the development guide.
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|
3998 Server configuration may change from a default one after choosing a virtual |
|
7f290929b32d
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diff
changeset
|
3999 server for a request. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4000 Request location configuration may change multiple times as a result of a |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4001 rewrite or internal redirect. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4002 The following example shows how to access HTTP configuration in runtime. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
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|
4003 </para> |
|
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HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4004 |
|
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HTTP section of the development guide.
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parents:
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diff
changeset
|
4005 <programlisting> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4006 static ngx_int_t |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4007 ngx_http_foo_handler(ngx_http_request_t *r) |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
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|
4008 { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4009 ngx_http_foo_loc_conf_t *flcf; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4010 |
|
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HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
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|
4011 flcf = ngx_http_get_module_loc_conf(r, ngx_http_foo_module); |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4012 |
|
7f290929b32d
HTTP section of the development guide.
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parents:
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diff
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|
4013 ... |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4014 } |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4015 </programlisting> |
|
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HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4016 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
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|
4017 </section> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
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|
4018 |
|
7f290929b32d
HTTP section of the development guide.
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parents:
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diff
changeset
|
4019 |
|
7f290929b32d
HTTP section of the development guide.
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diff
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|
4020 <section name="Phases" id="http_phases"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4021 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
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|
4022 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4023 Each HTTP request passes through a list of HTTP phases. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4024 Each phase is specialized in a particular type of processing. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4025 Most phases allow installing handlers. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4026 The phase handlers are called successively once the request reaches the phase. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4027 Many standard nginx modules install their phase handlers as a way to get called |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4028 at a specific request processing stage. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4029 Following is the list of nginx HTTP phases. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
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|
4030 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
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|
4031 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4032 <list type="bullet"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4033 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4034 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4035 <literal>NGX_HTTP_POST_READ_PHASE</literal> is the earliest phase. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4036 The <link doc="../http/ngx_http_realip_module.xml">ngx_http_realip_module</link> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4037 installs its handler at this phase. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4038 This allows to substitute client address before any other module is invoked |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4039 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
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|
4040 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4041 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4042 <literal>NGX_HTTP_SERVER_REWRITE_PHASE</literal> is used to run rewrite script, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4043 defined at the server level, that is out of any location block. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
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|
4044 The |
|
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HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4045 <link doc="../http/ngx_http_rewrite_module.xml">ngx_http_rewrite_module</link> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
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|
4046 installs its handler at this phase |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
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|
4047 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
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|
4048 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
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|
4049 <listitem> |
|
1935
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Vladimir Homutov <vl@nginx.com>
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diff
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|
4050 <literal>NGX_HTTP_FIND_CONFIG_PHASE</literal> — a special phase used to choose a |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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diff
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|
4051 location based on request URI. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
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|
4052 This phase does not allow installing any handlers. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4053 It only performs the default action of choosing a location. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4054 Before this phase, the server default location is assigned to the request. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4055 Any module requesting a location configuration, will receive the default server |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4056 location configuration. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4057 After this phase a new location is assigned to the request |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4058 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4059 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4060 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4061 <literal>NGX_HTTP_REWRITE_PHASE</literal> — same as |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4062 <literal>NGX_HTTP_SERVER_REWRITE_PHASE</literal>, but for a new location, |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4063 chosen at the prevous phase |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4064 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4065 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4066 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4067 <literal>NGX_HTTP_POST_REWRITE_PHASE</literal> — a special phase, used to |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4068 redirect the request to a new location, if the URI was changed during rewrite. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4069 The redirect is done by going back to |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4070 <literal>NGX_HTTP_FIND_CONFIG_PHASE</literal>. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4071 No handlers are allowed at this phase |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4072 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4073 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4074 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4075 <literal>NGX_HTTP_PREACCESS_PHASE</literal> — a common phase for different |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4076 types of handlers, not associated with access check. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4077 Standard nginx modules |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4078 <link doc="../http/ngx_http_limit_conn_module.xml">ngx_http_limit_conn_module |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4079 </link> and |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4080 <link doc="../http/ngx_http_limit_req_module.xml"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4081 ngx_http_limit_req_module</link> register their handlers at this phase |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4082 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4083 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4084 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4085 <literal>NGX_HTTP_ACCESS_PHASE</literal> — used to check access permissions |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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1928
diff
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|
4086 for the request. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4087 Standard nginx modules such as |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4088 <link doc="../http/ngx_http_access_module.xml">ngx_http_access_module</link> and |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4089 <link doc="../http/ngx_http_auth_basic_module.xml">ngx_http_auth_basic_module |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4090 </link> register their handlers at this phase. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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diff
changeset
|
4091 If configured so by the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4092 <link doc="../http/ngx_http_core_module.xml" id="satisfy"/> directive, only one |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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1928
diff
changeset
|
4093 of access phase handlers may allow access to the request in order to confinue |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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1928
diff
changeset
|
4094 processing |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4095 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4096 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
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diff
changeset
|
4097 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4098 <literal>NGX_HTTP_POST_ACCESS_PHASE</literal> — a special phase for the |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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diff
changeset
|
4099 <link doc="../http/ngx_http_core_module.xml" id="satisfy">satisfy any</link> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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diff
changeset
|
4100 case. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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1928
diff
changeset
|
4101 If some access phase handlers denied the access and none of them allowed, the |
|
7f290929b32d
HTTP section of the development guide.
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diff
changeset
|
4102 request is finalized. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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diff
changeset
|
4103 No handlers are supported at this phase |
|
7f290929b32d
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diff
changeset
|
4104 </listitem> |
|
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Roman Arutyunyan <arut@nginx.com>
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diff
changeset
|
4105 |
|
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diff
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|
4106 <listitem> |
|
1935
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Vladimir Homutov <vl@nginx.com>
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1932
diff
changeset
|
4107 <literal>NGX_HTTP_TRY_FILES_PHASE</literal> — a special phase, for the |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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diff
changeset
|
4108 <link doc="../http/ngx_http_core_module.xml" id="try_files"/> feature. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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diff
changeset
|
4109 No handlers are allowed at this phase |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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diff
changeset
|
4110 </listitem> |
|
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Roman Arutyunyan <arut@nginx.com>
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diff
changeset
|
4111 |
|
7f290929b32d
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Roman Arutyunyan <arut@nginx.com>
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diff
changeset
|
4112 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4113 <literal>NGX_HTTP_CONTENT_PHASE</literal> — a phase, at which the response |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4114 is supposed to be generated. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4115 Multiple nginx standard modules register their handers at this phase, for |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4116 example |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4117 <link doc="../http/ngx_http_index_module.xml">ngx_http_index_module</link> or |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4118 <literal>ngx_http_static_module</literal>. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4119 All these handlers are called sequentially until one of them finally produces |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4120 the output. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4121 It's also possible to set content handlers on a per-location basis. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4122 If the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4123 <link doc="../http/ngx_http_core_module.xml">ngx_http_core_module</link>'s |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4124 location configuration has <literal>handler</literal> set, this handler is |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4125 called as the content handler and content phase handlers are ignored |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4126 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4127 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4128 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4129 <literal>NGX_HTTP_LOG_PHASE</literal> is used to perform request logging. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4130 Currently, only the |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4131 <link doc="../http/ngx_http_log_module.xml">ngx_http_log_module</link> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4132 registers its handler |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4133 at this stage for access logging. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4134 Log phase handlers are called at the very end of request processing, right |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4135 before freeing the request |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4136 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4137 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4138 </list> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4139 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4140 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4141 Following is the example of a preaccess phase handler. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4142 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4143 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4144 <programlisting> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4145 static ngx_http_module_t ngx_http_foo_module_ctx = { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4146 NULL, /* preconfiguration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4147 ngx_http_foo_init, /* postconfiguration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4148 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4149 NULL, /* create main configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4150 NULL, /* init main configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4151 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4152 NULL, /* create server configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4153 NULL, /* merge server configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4154 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4155 NULL, /* create location configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4156 NULL /* merge location configuration */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4157 }; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4158 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4159 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4160 static ngx_int_t |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4161 ngx_http_foo_handler(ngx_http_request_t *r) |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4162 { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4163 ngx_str_t *ua; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4164 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4165 ua = r->headers_in->user_agent; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4166 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4167 if (ua == NULL) { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4168 return NGX_DECLINED; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4169 } |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4170 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4171 /* reject requests with "User-Agent: foo" */ |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4172 if (ua->value.len == 3 && ngx_strncmp(ua->value.data, "foo", 3) == 0) { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4173 return NGX_HTTP_FORBIDDEN; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4174 } |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4175 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4176 return NGX_DECLINED; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4177 } |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4178 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4179 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4180 static ngx_int_t |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4181 ngx_http_foo_init(ngx_conf_t *cf) |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4182 { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4183 ngx_http_handler_pt *h; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4184 ngx_http_core_main_conf_t *cmcf; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4185 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4186 cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module); |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4187 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4188 h = ngx_array_push(&cmcf->phases[NGX_HTTP_PREACCESS_PHASE].handlers); |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4189 if (h == NULL) { |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4190 return NGX_ERROR; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4191 } |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4192 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4193 *h = ngx_http_foo_handler; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4194 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4195 return NGX_OK; |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4196 } |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4197 </programlisting> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4198 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4199 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4200 Phase handlers are expected to return specific codes: |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4201 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4202 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4203 <list type="bullet"> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4204 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4205 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4206 <literal>NGX_OK</literal> — proceed to the next phase |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4207 </listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4208 |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4209 <listitem> |
|
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4210 <literal>NGX_DECLINED</literal> — proceed to the next handler of the current |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4211 phase. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4212 If current handler is the last in current phase, move to the next phase |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4213 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4214 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4215 <listitem> |
|
1935
be7490a66d1b
Style: use long dash with non-breaking space where appropriate.
Vladimir Homutov <vl@nginx.com>
parents:
1932
diff
changeset
|
4216 <literal>NGX_AGAIN, NGX_DONE</literal> — suspend phase handling until some |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4217 future event. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4218 This can be for example asynchronous I/O operation or just a delay. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
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1928
diff
changeset
|
4219 It is supposed, that phase handling will be resumed later by calling |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4220 <literal>ngx_http_core_run_phases()</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4221 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4222 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4223 <listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4224 Any other value returned by the phase handler is treated as a request |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4225 finalization code, in particular, HTTP response code. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4226 The request is finalized with the code provided |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4227 </listitem> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4228 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4229 </list> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4230 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4231 <para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4232 Some phases treat return codes in a slightly different way. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4233 At content phase, any return code other that <literal>NGX_DECLINED</literal> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4234 is considered a finalization code. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4235 As for the location content handlers, any return from them is considered a |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4236 finalization code. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4237 At access phase, in |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4238 <link doc="../http/ngx_http_core_module.xml" id="satisfy">satisfy any</link> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4239 mode, returning a code other |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4240 than <literal>NGX_OK, NGX_DECLINED, NGX_AGAIN, NGX_DONE</literal> is considered |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4241 a denial. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4242 If none of future access handlers allow access or deny with a new |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4243 code, the denial code will become the finalization code. |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4244 </para> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4245 |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4246 </section> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
4247 |
|
1939
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
4248 |
|
1959
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4249 <section name="Variables" id="http_variables"> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4250 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4251 <section name="Accessing existing variables" id="http_existing_variables"> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4252 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4253 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4254 Variables may be referenced using index (this is the most common method) |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4255 or names (see below in the section about creating variables). |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4256 Index is created at configuration stage, when a variable is added |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4257 to configuration. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4258 The variable index can be obtained using |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4259 <literal>ngx_http_get_variable_index()</literal>: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4260 <programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4261 ngx_str_t name; /* ngx_string("foo") */ |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4262 ngx_int_t index; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4263 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4264 index = ngx_http_get_variable_index(cf, &name); |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4265 </programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4266 Here, the <literal>cf</literal> is a pointer to nginx configuration and the |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4267 <literal>name</literal> points to a string with the variable name. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4268 The function returns <literal>NGX_ERROR</literal> on error or valid index |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4269 otherwise, which is typically stored somewhere in a module configuration for |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4270 future use. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4271 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4272 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4273 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4274 All HTTP variables are evaluated in the context of HTTP request and results |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4275 are specific to and cached in HTTP request. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4276 All functions that evaluate variables return |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4277 <literal>ngx_http_variable_value_t</literal> type, representing |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4278 the variable value: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4279 <programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4280 typedef ngx_variable_value_t ngx_http_variable_value_t; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4281 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4282 typedef struct { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4283 unsigned len:28; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4284 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4285 unsigned valid:1; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4286 unsigned no_cacheable:1; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4287 unsigned not_found:1; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4288 unsigned escape:1; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4289 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4290 u_char *data; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4291 } ngx_variable_value_t; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4292 </programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4293 where: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4294 <list type="bullet"> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4295 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4296 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4297 <literal>len</literal> — length of a value |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4298 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4299 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4300 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4301 <literal>data</literal> — value itself |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4302 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4303 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4304 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4305 <literal>valid</literal> — value is valid |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4306 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4307 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4308 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4309 <literal>not_found</literal> — variable was not found and thus |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4310 the <literal>data</literal> and <literal>len</literal> fields are irrelevant; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4311 this may happen, for example, with such variables as <var>$arg_foo</var> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4312 when a corresponding argument was not passed in a request |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4313 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4314 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4315 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4316 <literal>no_cacheable</literal> — do not cache result |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4317 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4318 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4319 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4320 <literal>escape</literal> — used internally by the logging module to mark |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4321 values that require escaping on output |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4322 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4323 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4324 </list> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4325 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4326 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4327 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4328 The <literal>ngx_http_get_flushed_variable()</literal> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4329 and <literal>ngx_http_get_indexed_variable()</literal> functions |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4330 are used to obtain the variable value. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4331 They have the same interface - accepting a HTTP request <literal>r</literal> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4332 as a context for evaluating the variable and an <literal>index</literal>, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4333 identifying it. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4334 Example of typical usage: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4335 <programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4336 ngx_http_variable_value_t *v; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4337 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4338 v = ngx_http_get_flushed_variable(r, index); |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4339 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4340 if (v == NULL || v->not_found) { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4341 /* we failed to get value or there is no such variable, handle it */ |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4342 return NGX_ERROR; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4343 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4344 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4345 /* some meaningful value is found */ |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4346 </programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4347 The difference between functions is that the |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4348 <literal>ngx_http_get_indexed_variable()</literal> returns cached value |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4349 and <literal>ngx_http_get_flushed_variable()</literal> flushes cache for |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4350 non-cacheable variables. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4351 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4352 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4353 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4354 There are cases when it is required to deal with variables which names are |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4355 not known at configuration time and thus they cannot be accessed using indexes, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4356 for example in modules like SSI or Perl. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4357 The <literal>ngx_http_get_variable(r, name, key)</literal> function may be |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4358 used in such cases. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4359 It searches for the <literal>variable</literal> with a given |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4360 <literal>name</literal> and its hash <literal>key</literal>. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4361 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4362 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4363 </section> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4364 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4365 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4366 <section name="Creating variables" id="http_creating_variables"> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4367 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4368 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4369 To create a variable <literal>ngx_http_add_variable()</literal> function |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4370 is used. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4371 It takes configuration (where variable is registered), variable name and |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4372 flags that control its behaviour: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4373 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4374 <list type="bullet"> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4375 <listitem><literal>NGX_HTTP_VAR_CHANGEABLE</literal> — allows redefining |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4376 the variable; If another module will define a variable with such name, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4377 no conflict will happen. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4378 For example, this allows user to override variables using the |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4379 <link doc="../http/ngx_http_rewrite_module.xml" id="set"/> directive. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4380 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4381 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4382 <listitem><literal>NGX_HTTP_VAR_NOCACHEABLE</literal> — disables caching, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4383 is useful for such variables as <literal>$time_local</literal> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4384 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4385 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4386 <listitem><literal>NGX_HTTP_VAR_NOHASH</literal> — indicates that |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4387 this variable is only accessible by index, not by name. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4388 This is a small optimization which may be used when it is known that the |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4389 variable is not needed in modules like SSI or Perl. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4390 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4391 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4392 <listitem><literal>NGX_HTTP_VAR_PREFIX</literal> — the name of this |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4393 variable is a prefix. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4394 A handler must implement additional logic to obtain value of specific |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4395 variable. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4396 For example, all “<literal>arg_</literal>” variables are processed by the |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4397 same handler which performs lookup in request arguments and returns value |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4398 of specific argument. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4399 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4400 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4401 </list> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4402 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4403 The function returns NULL in case of error or a pointer to |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4404 <literal>ngx_http_variable_t</literal>: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4405 <programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4406 struct ngx_http_variable_s { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4407 ngx_str_t name; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4408 ngx_http_set_variable_pt set_handler; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4409 ngx_http_get_variable_pt get_handler; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4410 uintptr_t data; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4411 ngx_uint_t flags; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4412 ngx_uint_t index; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4413 }; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4414 </programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4415 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4416 The <literal>get</literal> and <literal>set</literal> handlers |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4417 are called to obtain or set the variable value, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4418 <literal>data</literal> will be passed to variable handlers, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4419 <literal>index</literal> will hold assigned variable index, used to reference |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4420 the variable. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4421 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4422 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4423 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4424 Usually, a null-terminated static array of such structures is created |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4425 by a module and processed at the preconfiguration stage to add variables |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4426 into configuration: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4427 <programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4428 static ngx_http_variable_t ngx_http_foo_vars[] = { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4429 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4430 { ngx_string("foo_v1"), NULL, ngx_http_foo_v1_variable, NULL, 0, 0 }, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4431 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4432 { ngx_null_string, NULL, NULL, 0, 0, 0 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4433 }; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4434 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4435 static ngx_int_t |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4436 ngx_http_foo_add_variables(ngx_conf_t *cf) |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4437 { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4438 ngx_http_variable_t *var, *v; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4439 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4440 for (v = ngx_http_foo_vars; v->name.len; v++) { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4441 var = ngx_http_add_variable(cf, &v->name, v->flags); |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4442 if (var == NULL) { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4443 return NGX_ERROR; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4444 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4445 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4446 var->get_handler = v->get_handler; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4447 var->data = v->data; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4448 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4449 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4450 return NGX_OK; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4451 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4452 </programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4453 This function is used to initialize the <literal>preconfiguration</literal> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4454 field of the HTTP module context and is called before parsing HTTP configuration, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4455 so it could refer to these variables. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4456 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4457 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4458 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4459 The <literal>get</literal> handler is responsible for evaluating the variable |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4460 in a context of specific request, for example: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4461 <programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4462 static ngx_int_t |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4463 ngx_http_variable_connection(ngx_http_request_t *r, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4464 ngx_http_variable_value_t *v, uintptr_t data) |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4465 { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4466 u_char *p; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4467 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4468 p = ngx_pnalloc(r->pool, NGX_ATOMIC_T_LEN); |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4469 if (p == NULL) { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4470 return NGX_ERROR; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4471 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4472 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4473 v->len = ngx_sprintf(p, "%uA", r->connection->number) - p; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4474 v->valid = 1; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4475 v->no_cacheable = 0; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4476 v->not_found = 0; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4477 v->data = p; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4478 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4479 return NGX_OK; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4480 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4481 </programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4482 It returns <literal>NGX_ERROR</literal> in case of internal error |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4483 (for example, failed memory allocation) or <literal>NGX_OK</literal> otherwise. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4484 The status of variable evaluation may be understood by inspecting flags |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4485 of the <literal>ngx_http_variable_value_t</literal> (see description above). |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4486 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4487 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4488 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4489 The <literal>set</literal> handler allows setting the property |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4490 referred by the variable. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4491 For example, the <literal>$limit_rate</literal> variable set handler |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4492 modifies the request's <literal>limit_rate</literal> field: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4493 <programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4494 ... |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4495 { ngx_string("limit_rate"), ngx_http_variable_request_set_size, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4496 ngx_http_variable_request_get_size, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4497 offsetof(ngx_http_request_t, limit_rate), |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4498 NGX_HTTP_VAR_CHANGEABLE|NGX_HTTP_VAR_NOCACHEABLE, 0 }, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4499 ... |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4500 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4501 static void |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4502 ngx_http_variable_request_set_size(ngx_http_request_t *r, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4503 ngx_http_variable_value_t *v, uintptr_t data) |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4504 { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4505 ssize_t s, *sp; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4506 ngx_str_t val; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4507 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4508 val.len = v->len; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4509 val.data = v->data; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4510 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4511 s = ngx_parse_size(&val); |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4512 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4513 if (s == NGX_ERROR) { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4514 ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4515 "invalid size \"%V\"", &val); |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4516 return; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4517 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4518 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4519 sp = (ssize_t *) ((char *) r + data); |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4520 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4521 *sp = s; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4522 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4523 return; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4524 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4525 </programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4526 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4527 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4528 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4529 </section> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4530 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4531 </section> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4532 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4533 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4534 <section name="Complex values" id="http_complex_values"> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4535 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4536 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4537 A complex value, despite its name, provides an easy way to evaluate |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4538 expressions that may contain text, variables, and their combination. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4539 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4540 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4541 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4542 The complex value description in |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4543 <literal>ngx_http_compile_complex_value</literal> is compiled at the |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4544 configuration stage into <literal>ngx_http_complex_value_t</literal> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4545 which is used at runtime to obtain evaluated expression results. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4546 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4547 <programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4548 ngx_str_t *value; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4549 ngx_http_complex_value_t cv; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4550 ngx_http_compile_complex_value_t ccv; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4551 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4552 value = cf->args->elts; /* directive arguments */ |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4553 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4554 ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4555 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4556 ccv.cf = cf; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4557 ccv.value = &value[1]; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4558 ccv.complex_value = &cv; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4559 ccv.zero = 1; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4560 ccv.conf_prefix = 1; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4561 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4562 if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4563 return NGX_CONF_ERROR; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4564 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4565 </programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4566 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4567 Here, <literal>ccv</literal> holds all parameters that are required to |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4568 initialize the complex value <literal>cv</literal>: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4569 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4570 <list type="bullet"> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4571 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4572 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4573 <literal>cf</literal> — configuration pointer |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4574 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4575 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4576 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4577 <literal>value</literal> — string for parsing (input) |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4578 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4579 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4580 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4581 <literal>complex_value</literal> — compiled value (output) |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4582 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4583 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4584 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4585 <literal>zero</literal> — flag that enables zero-terminating value |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4586 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4587 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4588 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4589 <literal>conf_prefix</literal> — prefixes result with configuration prefix |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4590 (the directory where nginx is currently looking for configuration) |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4591 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4592 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4593 <listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4594 <literal>root_prefix</literal> — prefixes result with root prefix |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4595 (this is the normal nginx installation prefix) |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4596 </listitem> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4597 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4598 </list> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4599 The <literal>zero</literal> flag is usable when results are to be passed to |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4600 libraries that require zero-terminated strings, and prefixes are handy when |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4601 dealing with filenames. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4602 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4603 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4604 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4605 Upon successful compilation, <literal>cv.lengths</literal> may |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4606 be inspected to get information about the presence of variables |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4607 in the expression. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4608 The NULL value means that the expression contained static text only, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4609 and there is no need in storing it as a complex value, |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4610 so a simple string can be used. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4611 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4612 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4613 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4614 The <literal>ngx_http_set_complex_value_slot()</literal> is a convenient |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4615 function used to initialize complex value completely right in the directive |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4616 declaration. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4617 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4618 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4619 <para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4620 At runtime, a complex value may be calculated using the |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4621 <literal>ngx_http_complex_value()</literal> function: |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4622 <programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4623 ngx_str_t res; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4624 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4625 if (ngx_http_complex_value(r, &cv, &res) != NGX_OK) { |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4626 return NGX_ERROR; |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4627 } |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4628 </programlisting> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4629 Given the request <literal>r</literal> and previously compiled |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4630 value <literal>cv</literal> the function will evaluate |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4631 expression and put result into <literal>res</literal>. |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4632 </para> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4633 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4634 </section> |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4635 |
|
d0aebb2337ec
Added the "Variables" section to the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1958
diff
changeset
|
4636 |
|
1967
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4637 <section name="Request redirection" id="http_request_redirection"> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4638 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4639 <para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4640 An HTTP request is always connected to a location via the |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4641 <literal>loc_conf</literal> field of the <literal>ngx_http_request_t</literal> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4642 structure. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4643 This means that at any point the location configuration of any module can be |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4644 retrieved from the request by calling |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4645 <literal>ngx_http_get_module_loc_conf(r, module)</literal>. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4646 Request location may be changed several times throughout its lifetime. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4647 Initially, a default server location of the default server is assigned to a |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4648 request. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4649 Once a request switches to a different server (chosen by the HTTP |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4650 <header>Host</header> header or SSL SNI extension), the request switches to the |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4651 default location of that server as well. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4652 The next change of the location takes place at the |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4653 <literal>NGX_HTTP_FIND_CONFIG_PHASE</literal> request phase. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4654 At this phase a location is chosen by request URI among all non-named locations |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4655 configured for the server. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4656 The |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4657 <link doc="../http/ngx_http_rewrite_module.xml">ngx_http_rewrite_module</link> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4658 may change the request URI at the |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4659 <literal>NGX_HTTP_REWRITE_PHASE</literal> request phase as a result of |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4660 <link doc="../http/ngx_http_rewrite_module.xml" id="rewrite">rewrite</link> and |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4661 return to the <literal>NGX_HTTP_FIND_CONFIG_PHASE</literal> phase for choosing a |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4662 new location based on the new URI. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4663 </para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4664 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4665 <para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4666 It is also possible to redirect a request to a new location at any point by |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4667 calling one of the functions |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4668 <literal>ngx_http_internal_redirect(r, uri, args)</literal> or |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4669 <literal>ngx_http_named_location(r, name)</literal>. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4670 </para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4671 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4672 <para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4673 The function <literal>ngx_http_internal_redirect(r, uri, args)</literal> changes |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4674 the request URI and returns the request to the |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4675 <literal>NGX_HTTP_SERVER_REWRITE_PHASE</literal> phase. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4676 The request proceeds with a server default location. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4677 Later at <literal>NGX_HTTP_FIND_CONFIG_PHASE</literal> a new location is chosen |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4678 based on the new request URI. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4679 </para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4680 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4681 <para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4682 The following example performs an internal redirect with the new request |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4683 arguments. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4684 </para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4685 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4686 <programlisting> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4687 ngx_int_t |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4688 ngx_http_foo_redirect(ngx_http_request_t *r) |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4689 { |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4690 ngx_str_t uri, args; |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4691 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4692 ngx_str_set(&uri, "/foo"); |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4693 ngx_str_set(&args, "bar=1"); |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4694 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4695 return ngx_http_internal_redirect(r, &uri, &args); |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4696 } |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4697 </programlisting> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4698 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4699 <para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4700 The function <literal>ngx_http_named_location(r, name)</literal> redirects |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4701 a request to a named location. The name of the location is passed as the |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4702 argument. The location is looked up among all named locations of the current |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4703 server, after which the requests switches to the |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4704 <literal>NGX_HTTP_REWRITE_PHASE</literal> phase. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4705 </para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4706 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4707 <para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4708 The following example performs a redirect to a named location @foo. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4709 </para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4710 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4711 <programlisting> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4712 ngx_int_t |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4713 ngx_http_foo_named_redirect(ngx_http_request_t *r) |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4714 { |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4715 ngx_str_t name; |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4716 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4717 ngx_str_set(&name, "foo"); |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4718 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4719 return ngx_http_named_location(r, &name); |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4720 } |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4721 </programlisting> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4722 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4723 <para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4724 Both functions <literal>ngx_http_internal_redirect(r, uri, args)</literal> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4725 and <literal>ngx_http_named_location(r, name)</literal> may be called when |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4726 a request already has some contexts saved in its <literal>ctx</literal> field |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4727 by nginx modules. These contexts could become inconsistent with the new |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4728 location configuration. To prevent inconsistency, all request contexts are |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4729 erased by both redirect functions. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4730 </para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4731 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4732 <para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4733 Redirected and rewritten requests become internal and may access the |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4734 <link doc="../http/ngx_http_core_module.xml" id="internal">internal</link> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4735 locations. Internal requests have the <literal>internal</literal> flag set. |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4736 </para> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4737 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4738 </section> |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4739 |
|
ef27e3ef0c46
The HTTP request redirection section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1960
diff
changeset
|
4740 |
|
1960
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4741 <section name="Response" id="http_response"> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4742 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4743 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4744 An HTTP response in nginx is produced by sending the response header followed by |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4745 the optional response body. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4746 Both header and body are passed through a chain of filters and eventually get |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4747 written to the client socket. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4748 An nginx module can install its handler into the header or body filter chain |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4749 and process the output coming from the previous handler. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4750 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4751 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4752 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4753 <section name="Response header" id="http_response_header"> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4754 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4755 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4756 Output header is sent by the function |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4757 <literal>ngx_http_send_header(r)</literal>. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4758 Prior to calling this function, <literal>r->headers_out</literal> should contain |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4759 all the data required to produce the HTTP response header. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4760 It's always required to set the <literal>status</literal> field of |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4761 <literal>r->headers_out</literal>. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4762 If the response status suggests that a response body follows the header, |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4763 <literal>content_length_n</literal> can be set as well. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4764 The default value for this field is -1, which means that the body size is |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4765 unknown. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4766 In this case, chunked transfer encoding is used. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4767 To output an arbitrary header, <literal>headers</literal> list should be |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4768 appended. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4769 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4770 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4771 <programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4772 static ngx_int_t |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4773 ngx_http_foo_content_handler(ngx_http_request_t *r) |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4774 { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4775 ngx_int_t rc; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4776 ngx_table_elt_t *h; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4777 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4778 /* send header */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4779 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4780 r->headers_out.status = NGX_HTTP_OK; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4781 r->headers_out.content_length_n = 3; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4782 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4783 /* X-Foo: foo */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4784 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4785 h = ngx_list_push(&r->headers_out.headers); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4786 if (h == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4787 return NGX_ERROR; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4788 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4789 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4790 h->hash = 1; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4791 ngx_str_set(&h->key, "X-Foo"); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4792 ngx_str_set(&h->value, "foo"); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4793 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4794 rc = ngx_http_send_header(r); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4795 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4796 if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4797 return rc; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4798 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4799 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4800 /* send body */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4801 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4802 ... |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4803 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4804 </programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4805 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4806 </section> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4807 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4808 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4809 <section name="Header filters" id="http_header_filters"> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4810 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4811 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4812 The <literal>ngx_http_send_header(r)</literal> function invokes the header |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4813 filter chain by calling the top header filter handler |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4814 <literal>ngx_http_top_header_filter</literal>. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4815 It's assumed that every header handler calls the next handler in chain until |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4816 the final handler <literal>ngx_http_header_filter(r)</literal> is called. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4817 The final header handler constructs the HTTP response based on |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4818 <literal>r->headers_out</literal> and passes it to the |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4819 <literal>ngx_http_writer_filter</literal> for output. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4820 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4821 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4822 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4823 To add a handler to the header filter chain, one should store its address in |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4824 <literal>ngx_http_top_header_filter</literal> global variable at configuration |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4825 time. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4826 The previous handler address is normally stored in a module's static variable |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4827 and is called by the newly added handler before exiting. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4828 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4829 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4830 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4831 The following is an example header filter module, adding the HTTP header |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4832 "X-Foo: foo" to every output with the status 200. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4833 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4834 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4835 <programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4836 #include <ngx_config.h> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4837 #include <ngx_core.h> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4838 #include <ngx_http.h> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4839 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4840 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4841 static ngx_int_t ngx_http_foo_header_filter(ngx_http_request_t *r); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4842 static ngx_int_t ngx_http_foo_header_filter_init(ngx_conf_t *cf); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4843 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4844 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4845 static ngx_http_module_t ngx_http_foo_header_filter_module_ctx = { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4846 NULL, /* preconfiguration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4847 ngx_http_foo_header_filter_init, /* postconfiguration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4848 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4849 NULL, /* create main configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4850 NULL, /* init main configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4851 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4852 NULL, /* create server configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4853 NULL, /* merge server configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4854 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4855 NULL, /* create location configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4856 NULL /* merge location configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4857 }; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4858 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4859 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4860 ngx_module_t ngx_http_foo_header_filter_module = { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4861 NGX_MODULE_V1, |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4862 &ngx_http_foo_header_filter_module_ctx, /* module context */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4863 NULL, /* module directives */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4864 NGX_HTTP_MODULE, /* module type */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4865 NULL, /* init master */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4866 NULL, /* init module */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4867 NULL, /* init process */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4868 NULL, /* init thread */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4869 NULL, /* exit thread */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4870 NULL, /* exit process */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4871 NULL, /* exit master */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4872 NGX_MODULE_V1_PADDING |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4873 }; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4874 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4875 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4876 static ngx_http_output_header_filter_pt ngx_http_next_header_filter; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4877 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4878 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4879 static ngx_int_t |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4880 ngx_http_foo_header_filter(ngx_http_request_t *r) |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4881 { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4882 ngx_table_elt_t *h; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4883 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4884 /* |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4885 * The filter handler adds "X-Foo: foo" header |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4886 * to every HTTP 200 response |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4887 */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4888 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4889 if (r->headers_out.status != NGX_HTTP_OK) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4890 return ngx_http_next_header_filter(r); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4891 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4892 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4893 h = ngx_list_push(&r->headers_out.headers); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4894 if (h == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4895 return NGX_ERROR; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4896 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4897 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4898 h->hash = 1; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4899 ngx_str_set(&h->key, "X-Foo"); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4900 ngx_str_set(&h->value, "foo"); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4901 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4902 return ngx_http_next_header_filter(r); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4903 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4904 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4905 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4906 static ngx_int_t |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4907 ngx_http_foo_header_filter_init(ngx_conf_t *cf) |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4908 { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4909 ngx_http_next_header_filter = ngx_http_top_header_filter; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4910 ngx_http_top_header_filter = ngx_http_foo_header_filter; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4911 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4912 return NGX_OK; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4913 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4914 </programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4915 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4916 </section> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4917 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4918 </section> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4919 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4920 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4921 <section name="Response body" id="http_response_body"> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4922 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4923 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4924 Response body is sent by calling the function |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4925 <literal>ngx_http_output_filter(r, cl)</literal>. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4926 The function can be called multiple times. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4927 Each time it sends a part of the response body passed as a buffer chain. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4928 The last body buffer should have the <literal>last_buf</literal> flag set. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4929 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4930 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4931 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4932 The following example produces a complete HTTP output with "foo" as its body. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4933 In order for the example to work not only as a main request but as a subrequest |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4934 as well, the <literal>last_in_chain_flag</literal> is set in the last buffer |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4935 of the output. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4936 The <literal>last_buf</literal> flag is set only for the main request since |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4937 a subrequest's last buffers does not end the entire output. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4938 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4939 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4940 <programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4941 static ngx_int_t |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4942 ngx_http_bar_content_handler(ngx_http_request_t *r) |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4943 { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4944 ngx_int_t rc; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4945 ngx_buf_t *b; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4946 ngx_chain_t out; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4947 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4948 /* send header */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4949 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4950 r->headers_out.status = NGX_HTTP_OK; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4951 r->headers_out.content_length_n = 3; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4952 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4953 rc = ngx_http_send_header(r); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4954 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4955 if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4956 return rc; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4957 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4958 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4959 /* send body */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4960 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4961 b = ngx_calloc_buf(r->pool); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4962 if (b == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4963 return NGX_ERROR; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4964 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4965 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4966 b->last_buf = (r == r->main) ? 1: 0; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4967 b->last_in_chain = 1; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4968 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4969 b->memory = 1; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4970 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4971 b->pos = (u_char *) "foo"; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4972 b->last = b->pos + 3; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4973 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4974 out.buf = b; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4975 out.next = NULL; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4976 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4977 return ngx_http_output_filter(r, &out); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4978 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4979 </programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4980 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4981 </section> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4982 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4983 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4984 <section name="Body filters" id="http_body_filters"> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4985 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4986 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4987 The function <literal>ngx_http_output_filter(r, cl)</literal> invokes the |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4988 body filter chain by calling the top body filter handler |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4989 <literal>ngx_http_top_body_filter</literal>. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4990 It's assumed that every body handler calls the next handler in chain until |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4991 the final handler <literal>ngx_http_write_filter(r, cl)</literal> is called. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4992 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4993 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4994 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4995 A body filter handler receives a chain of buffers. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4996 The handler is supposed to process the buffers and pass a possibly new chain to |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4997 the next handler. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4998 It's worth noting that the chain links <literal>ngx_chain_t</literal> of the |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
4999 incoming chain belong to the caller. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5000 They should never be reused or changed. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5001 Right after the handler completes, the caller can use its output chain links |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5002 to keep track of the buffers it has sent. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5003 To save the buffer chain or to substitute some buffers before sending further, |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5004 a handler should allocate its own chain links. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5005 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5006 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5007 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5008 Following is the example of a simple body filter counting the number of |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5009 body bytes. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5010 The result is available as the <literal>$counter</literal> variable which can be |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5011 used in the access log. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5012 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5013 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5014 <programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5015 #include <ngx_config.h> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5016 #include <ngx_core.h> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5017 #include <ngx_http.h> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5018 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5019 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5020 typedef struct { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5021 off_t count; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5022 } ngx_http_counter_filter_ctx_t; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5023 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5024 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5025 static ngx_int_t ngx_http_counter_body_filter(ngx_http_request_t *r, |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5026 ngx_chain_t *in); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5027 static ngx_int_t ngx_http_counter_variable(ngx_http_request_t *r, |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5028 ngx_http_variable_value_t *v, uintptr_t data); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5029 static ngx_int_t ngx_http_counter_add_variables(ngx_conf_t *cf); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5030 static ngx_int_t ngx_http_counter_filter_init(ngx_conf_t *cf); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5031 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5032 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5033 static ngx_http_module_t ngx_http_counter_filter_module_ctx = { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5034 ngx_http_counter_add_variables, /* preconfiguration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5035 ngx_http_counter_filter_init, /* postconfiguration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5036 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5037 NULL, /* create main configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5038 NULL, /* init main configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5039 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5040 NULL, /* create server configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5041 NULL, /* merge server configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5042 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5043 NULL, /* create location configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5044 NULL /* merge location configuration */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5045 }; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5046 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5047 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5048 ngx_module_t ngx_http_counter_filter_module = { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5049 NGX_MODULE_V1, |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5050 &ngx_http_counter_filter_module_ctx, /* module context */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5051 NULL, /* module directives */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5052 NGX_HTTP_MODULE, /* module type */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5053 NULL, /* init master */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5054 NULL, /* init module */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5055 NULL, /* init process */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5056 NULL, /* init thread */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5057 NULL, /* exit thread */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5058 NULL, /* exit process */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5059 NULL, /* exit master */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5060 NGX_MODULE_V1_PADDING |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5061 }; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5062 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5063 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5064 static ngx_http_output_body_filter_pt ngx_http_next_body_filter; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5065 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5066 static ngx_str_t ngx_http_counter_name = ngx_string("counter"); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5067 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5068 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5069 static ngx_int_t |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5070 ngx_http_counter_body_filter(ngx_http_request_t *r, ngx_chain_t *in) |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5071 { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5072 ngx_chain_t *cl; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5073 ngx_http_counter_filter_ctx_t *ctx; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5074 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5075 ctx = ngx_http_get_module_ctx(r, ngx_http_counter_filter_module); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5076 if (ctx == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5077 ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_counter_filter_ctx_t)); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5078 if (ctx == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5079 return NGX_ERROR; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5080 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5081 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5082 ngx_http_set_ctx(r, ctx, ngx_http_counter_filter_module); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5083 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5084 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5085 for (cl = in; cl; cl = cl->next) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5086 ctx->count += ngx_buf_size(cl->buf); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5087 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5088 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5089 return ngx_http_next_body_filter(r, in); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5090 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5091 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5092 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5093 static ngx_int_t |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5094 ngx_http_counter_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5095 uintptr_t data) |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5096 { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5097 u_char *p; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5098 ngx_http_counter_filter_ctx_t *ctx; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5099 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5100 ctx = ngx_http_get_module_ctx(r, ngx_http_counter_filter_module); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5101 if (ctx == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5102 v->not_found = 1; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5103 return NGX_OK; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5104 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5105 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5106 p = ngx_pnalloc(r->pool, NGX_OFF_T_LEN); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5107 if (p == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5108 return NGX_ERROR; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5109 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5110 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5111 v->data = p; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5112 v->len = ngx_sprintf(p, "%O", ctx->count) - p; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5113 v->valid = 1; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5114 v->no_cacheable = 0; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5115 v->not_found = 0; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5116 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5117 return NGX_OK; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5118 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5119 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5120 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5121 static ngx_int_t |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5122 ngx_http_counter_add_variables(ngx_conf_t *cf) |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5123 { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5124 ngx_http_variable_t *var; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5125 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5126 var = ngx_http_add_variable(cf, &ngx_http_counter_name, 0); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5127 if (var == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5128 return NGX_ERROR; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5129 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5130 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5131 var->get_handler = ngx_http_counter_variable; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5132 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5133 return NGX_OK; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5134 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5135 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5136 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5137 static ngx_int_t |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5138 ngx_http_counter_filter_init(ngx_conf_t *cf) |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5139 { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5140 ngx_http_next_body_filter = ngx_http_top_body_filter; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5141 ngx_http_top_body_filter = ngx_http_counter_body_filter; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5142 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5143 return NGX_OK; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5144 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5145 </programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5146 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5147 </section> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5148 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5149 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5150 <section name="Building filter modules" id="http_building_filter_modules"> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5151 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5152 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5153 When writing a body or header filter, a special care should be taken of the |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5154 filters order. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5155 There's a number of header and body filters registered by nginx standard |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5156 modules. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5157 It's important to register a filter module in the right place in respect to |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5158 other filters. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5159 Normally, filters are registered by modules in their postconfiguration handlers. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5160 The order in which filters are called is obviously the reverse of when they are |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5161 registered. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5162 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5163 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5164 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5165 A special slot <literal>HTTP_AUX_FILTER_MODULES</literal> for third-party filter |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5166 modules is provided by nginx. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5167 To register a filter module in this slot, the <literal>ngx_module_type</literal> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5168 variable should be set to the value of <literal>HTTP_AUX_FILTER</literal> in |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5169 module's configuration. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5170 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5171 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5172 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5173 The following example shows a filter module config file assuming it only has |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5174 one source file <literal>ngx_http_foo_filter_module.c</literal> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5175 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5176 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5177 <programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5178 ngx_module_type=HTTP_AUX_FILTER |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5179 ngx_module_name=ngx_http_foo_filter_module |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5180 ngx_module_srcs="$ngx_addon_dir/ngx_http_foo_filter_module.c" |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5181 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5182 . auto/module |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5183 </programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5184 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5185 </section> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5186 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5187 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5188 <section name="Buffer reuse" id="http_body_buffers_reuse"> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5189 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5190 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5191 When issuing or altering a stream of buffers, it's often desirable to reuse the |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5192 allocated buffers. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5193 A standard approach widely adopted in nginx code is to keep two buffer chains |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5194 for this purpose: <literal>free</literal> and <literal>busy</literal>. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5195 The <literal>free</literal> chain keeps all free buffers. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5196 These buffers can be reused. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5197 The <literal>busy</literal> chain keeps all buffers sent by the current |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5198 module which are still in use by some other filter handler. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5199 A buffer is considered in use if its size is greater than zero. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5200 Normally, when a buffer is consumed by a filter, its <literal>pos</literal> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5201 (or <literal>file_pos</literal> for a file buffer) is moved towards |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5202 <literal>last</literal> (<literal>file_last</literal> for a file buffer). |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5203 Once a buffer is completely consumed, it's ready to be reused. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5204 To update the <literal>free</literal> chain with newly freed buffers, |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5205 it's enough to iterate over the <literal>busy</literal> chain and move the zero |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5206 size buffers at the head of it to <literal>free</literal>. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5207 This operation is so common that there is a special function |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5208 <literal>ngx_chain_update_chains(free, busy, out, tag)</literal> which does |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5209 this. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5210 The function appends the output chain <literal>out</literal> to |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5211 <literal>busy</literal> and moves free buffers from the top of |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5212 <literal>busy</literal> to <literal>free</literal>. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5213 Only the buffers with the given <literal>tag</literal> are reused. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5214 This lets a module reuse only the buffers allocated by itself. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5215 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5216 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5217 <para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5218 The following example is a body filter inserting the “foo” string before each |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5219 incoming buffer. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5220 The new buffers allocated by the module are reused if possible. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5221 Note that for this example to work properly, it's also required to set up a |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5222 header filter and reset <literal>content_length_n</literal> to -1, which is |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5223 beyond the scope of this section. |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5224 </para> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5225 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5226 <programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5227 typedef struct { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5228 ngx_chain_t *free; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5229 ngx_chain_t *busy; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5230 } ngx_http_foo_filter_ctx_t; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5231 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5232 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5233 ngx_int_t |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5234 ngx_http_foo_body_filter(ngx_http_request_t *r, ngx_chain_t *in) |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5235 { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5236 ngx_int_t rc; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5237 ngx_buf_t *b; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5238 ngx_chain_t *cl, *tl, *out, **ll; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5239 ngx_http_foo_filter_ctx_t *ctx; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5240 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5241 ctx = ngx_http_get_module_ctx(r, ngx_http_foo_filter_module); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5242 if (ctx == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5243 ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_foo_filter_ctx_t)); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5244 if (ctx == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5245 return NGX_ERROR; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5246 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5247 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5248 ngx_http_set_ctx(r, ctx, ngx_http_foo_filter_module); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5249 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5250 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5251 /* create a new chain "out" from "in" with all the changes */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5252 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5253 ll = &out; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5254 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5255 for (cl = in; cl; cl = cl->next) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5256 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5257 /* append "foo" in a reused buffer if possible */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5258 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5259 tl = ngx_chain_get_free_buf(r->pool, &ctx->free); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5260 if (tl == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5261 return NGX_ERROR; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5262 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5263 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5264 b = tl->buf; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5265 b->tag = (ngx_buf_tag_t) &ngx_http_foo_filter_module; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5266 b->memory = 1; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5267 b->pos = (u_char *) "foo"; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5268 b->last = b->pos + 3; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5269 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5270 *ll = tl; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5271 ll = &tl->next; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5272 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5273 /* append the next incoming buffer */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5274 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5275 tl = ngx_alloc_chain_link(r->pool); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5276 if (tl == NULL) { |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5277 return NGX_ERROR; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5278 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5279 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5280 tl->buf = cl->buf; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5281 *ll = tl; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5282 ll = &tl->next; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5283 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5284 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5285 *ll = NULL; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5286 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5287 /* send the new chain */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5288 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5289 rc = ngx_http_next_body_filter(r, out); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5290 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5291 /* update "busy" and "free" chains for reuse */ |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5292 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5293 ngx_chain_update_chains(r->pool, &ctx->free, &ctx->busy, &out, |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5294 (ngx_buf_tag_t) &ngx_http_foo_filter_module); |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5295 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5296 return rc; |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5297 } |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5298 </programlisting> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5299 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5300 </section> |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5301 |
|
9550ea66abdd
HTTP response section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1959
diff
changeset
|
5302 |
|
1939
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5303 <section name="Load balancing" id="http_load_balancing"> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5304 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5305 <para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5306 The |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5307 <link doc="../http/ngx_http_upstream_module.xml">ngx_http_upstream_module</link> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5308 provides basic functionality to pass requests to remote servers. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5309 This functionality is used by modules that implement specific protocols, |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5310 such as HTTP or FastCGI. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5311 The module also provides an interface for creating custom |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5312 load balancing modules and implements a default round-robin balancing method. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5313 </para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5314 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5315 <para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5316 Examples of modules that implement alternative load balancing methods are |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5317 <link doc="../http/ngx_http_upstream_module.xml" id="least_conn"/> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5318 and <link doc="../http/ngx_http_upstream_module.xml" id="hash"/>. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5319 Note that these modules are actually implemented as extensions of the upstream |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5320 module and share a lot of code, such as representation of a server group. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5321 The <link doc="../http/ngx_http_upstream_module.xml" id="keepalive"/> module |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5322 is an example of an independent module, extending upstream functionality. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5323 </para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5324 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5325 <para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5326 The |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5327 <link doc="../http/ngx_http_upstream_module.xml">ngx_http_upstream_module</link> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5328 may be configured explicitly by placing the corresponding |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5329 <link doc="../http/ngx_http_upstream_module.xml" id="upstream"/> block into |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5330 the configuration file, or implicitly by using directives |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5331 that accept a URL evaluated at some point to the list of servers, |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5332 for example, |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5333 <link doc="../http/ngx_http_proxy_module.xml" id="proxy_pass"/>. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5334 Only explicit configurations may use an alternative load balancing method. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5335 The upstream module configuration has its own directive context |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5336 <literal>NGX_HTTP_UPS_CONF</literal>. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5337 The structure is defined as follows: |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5338 <programlisting> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5339 struct ngx_http_upstream_srv_conf_s { |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5340 ngx_http_upstream_peer_t peer; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5341 void **srv_conf; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5342 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5343 ngx_array_t *servers; /* ngx_http_upstream_server_t */ |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5344 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5345 ngx_uint_t flags; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5346 ngx_str_t host; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5347 u_char *file_name; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5348 ngx_uint_t line; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5349 in_port_t port; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5350 ngx_uint_t no_port; /* unsigned no_port:1 */ |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5351 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5352 #if (NGX_HTTP_UPSTREAM_ZONE) |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5353 ngx_shm_zone_t *shm_zone; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5354 #endif |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5355 }; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5356 </programlisting> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5357 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5358 <list type="bullet"> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5359 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5360 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5361 <literal>srv_conf</literal> — configuration context of upstream modules |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5362 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5363 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5364 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5365 <literal>servers</literal> — array of |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5366 <literal>ngx_http_upstream_server_t</literal>, the result of parsing a set of |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5367 <link doc="../http/ngx_http_upstream_module.xml" id="server"/> directives |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5368 in the <literal>upstream</literal> block |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5369 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5370 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5371 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5372 <literal>flags</literal> — flags that mostly mark which features |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5373 (configured as parameters of |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5374 the <link doc="../http/ngx_http_upstream_module.xml" id="server"/> directive) |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5375 are supported by the particular load balancing method. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5376 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5377 <list type="bullet"> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5378 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5379 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5380 <literal>NGX_HTTP_UPSTREAM_CREATE</literal> — used to distinguish explicitly |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5381 defined upstreams from automatically created by |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5382 <link doc="../http/ngx_http_proxy_module.xml" id="proxy_pass"/> and “friends” |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5383 (FastCGI, SCGI, etc.) |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5384 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5385 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5386 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5387 <literal>NGX_HTTP_UPSTREAM_WEIGHT</literal> — “<literal>weight</literal>” |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5388 is supported |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5389 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5390 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5391 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5392 <literal>NGX_HTTP_UPSTREAM_MAX_FAILS</literal> — “<literal>max_fails</literal>” |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5393 is supported |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5394 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5395 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5396 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5397 <literal>NGX_HTTP_UPSTREAM_FAIL_TIMEOUT</literal> — |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5398 “<literal>fail_timeout</literal>” is supported |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5399 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5400 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5401 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5402 <literal>NGX_HTTP_UPSTREAM_DOWN</literal> — “<literal>down</literal>” |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5403 is supported |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5404 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5405 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5406 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5407 <literal>NGX_HTTP_UPSTREAM_BACKUP</literal> — “<literal>backup</literal>” |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5408 is supported |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5409 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5410 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5411 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5412 <literal>NGX_HTTP_UPSTREAM_MAX_CONNS</literal> — “<literal>max_conns</literal>” |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5413 is supported |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5414 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5415 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5416 </list> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5417 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5418 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5419 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5420 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5421 <literal>host</literal> — the name of an upstream |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5422 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5423 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5424 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5425 <literal>file_name, line</literal> — the name of the configuration file |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5426 and the line where the <literal>upstream</literal> block is located |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5427 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5428 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5429 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5430 <literal>port</literal> and <literal>no_port</literal> — unused by explicit |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5431 upstreams |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5432 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5433 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5434 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5435 <literal>shm_zone</literal> — a shared memory zone used by this upstream, if any |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5436 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5437 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5438 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5439 <literal>peer</literal> — an object that holds generic methods for |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5440 initializing upstream configuration: |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5441 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5442 <programlisting> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5443 typedef struct { |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5444 ngx_http_upstream_init_pt init_upstream; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5445 ngx_http_upstream_init_peer_pt init; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5446 void *data; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5447 } ngx_http_upstream_peer_t; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5448 </programlisting> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5449 A module that implements a load balancing algorithm must set these |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5450 methods and initialize private <literal>data</literal>. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5451 If <literal>init_upstream</literal> was not initialized during configuration |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5452 parsing, <literal>ngx_http_upstream_module</literal> sets it to default |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5453 <literal>ngx_http_upstream_init_round_robin</literal>. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5454 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5455 <list type="bullet"> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5456 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5457 <literal>init_upstream(cf, us)</literal> — configuration-time |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5458 method responsible for initializing a group of servers and |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5459 initializing the <literal>init()</literal> method in case of success. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5460 A typical load balancing module uses a list of servers in the upstream block |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5461 to create some efficient data structure that it uses and saves own |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5462 configuration to the <literal>data</literal> field. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5463 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5464 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5465 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5466 <literal>init(r, us)</literal> — initializes per-request |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5467 <literal>ngx_http_upstream_peer_t.peer</literal> (not to be confused with the |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5468 <literal>ngx_http_upstream_srv_conf_t.peer</literal> described above which |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5469 is per-upstream) structure that is used for load balancing. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5470 It will be passed as <literal>data</literal> argument to all callbacks that |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5471 deal with server selection. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5472 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5473 </list> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5474 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5475 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5476 </list> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5477 </para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5478 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5479 <para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5480 When nginx has to pass a request to another host for processing, it uses |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5481 a configured load balancing method to obtain an address to connect to. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5482 The method is taken from the |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5483 <literal>ngx_http_upstream_peer_t.peer</literal> object |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5484 of type <literal>ngx_peer_connection_t</literal>: |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5485 <programlisting> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5486 struct ngx_peer_connection_s { |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5487 [...] |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5488 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5489 struct sockaddr *sockaddr; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5490 socklen_t socklen; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5491 ngx_str_t *name; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5492 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5493 ngx_uint_t tries; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5494 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5495 ngx_event_get_peer_pt get; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5496 ngx_event_free_peer_pt free; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5497 ngx_event_notify_peer_pt notify; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5498 void *data; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5499 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5500 #if (NGX_SSL || NGX_COMPAT) |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5501 ngx_event_set_peer_session_pt set_session; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5502 ngx_event_save_peer_session_pt save_session; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5503 #endif |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5504 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5505 [..] |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5506 }; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5507 </programlisting> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5508 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5509 The structure has the following fields: |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5510 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5511 <list type="bullet"> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5512 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5513 <literal>sockaddr</literal>, <literal>socklen</literal>, |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5514 <literal>name</literal> — address of an upstream server to connect to; |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5515 this is the output parameter of a load balancing method |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5516 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5517 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5518 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5519 <literal>data</literal> — per-request load balancing method data; keeps the |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5520 state of selection algorithm and usually includes the link to upstream |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5521 configuration. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5522 It will be passed as an argument to all methods that deal with server selection |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5523 (see below) |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5524 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5525 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5526 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5527 <literal>tries</literal> — allowed |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5528 <link doc="../http/ngx_http_proxy_module.xml" id="proxy_next_upstream_tries">number</link> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5529 of attempts to connect to an upstream. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5530 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5531 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5532 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5533 <literal>get</literal>, <literal>free</literal>, <literal>notify</literal>, |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5534 <literal>set_session</literal>, and <literal>save_session</literal> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5535 - methods of the load balancing module, see description below |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5536 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5537 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5538 </list> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5539 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5540 </para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5541 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5542 <para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5543 All methods accept at least two arguments: peer connection object |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5544 <literal>pc</literal> and the <literal>data</literal> created by |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5545 <literal>ngx_http_upstream_srv_conf_t.peer.init()</literal>. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5546 Note that in general case it may differ from <literal>pc.data</literal> due |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5547 to “chaining” of load balancing modules. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5548 </para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5549 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5550 <para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5551 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5552 <list type="bullet"> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5553 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5554 <literal>get(pc, data)</literal> — the method is called when the upstream |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5555 module is ready to pass a request to an upstream server and needs to know |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5556 its address. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5557 The method is responsible to fill in the <literal>sockaddr</literal>, |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5558 <literal>socklen</literal>, and <literal>name</literal> fields of |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5559 <literal>ngx_peer_connection_t</literal> structure. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5560 The return value may be one of: |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5561 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5562 <list type="bullet"> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5563 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5564 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5565 <literal>NGX_OK</literal> — server was selected |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5566 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5567 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5568 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5569 <literal>NGX_ERROR</literal> — internal error occurred |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5570 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5571 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5572 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5573 <literal>NGX_BUSY</literal> — there are no available servers at the moment. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5574 This can happen due to many reasons, such as: dynamic server group is empty, |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5575 all servers in the group are in the failed state, |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5576 all servers in the group are already |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5577 handling the maximum number of connections or similar. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5578 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5579 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5580 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5581 <literal>NGX_DONE</literal> — this is set by the <literal>keepalive</literal> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5582 module to indicate that the underlying connection was reused and there is no |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5583 need to create a new connection to the upstream server. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5584 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5585 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5586 <!-- |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5587 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5588 <literal>NGX_ABORT</literal> — this is set by the <literal>queue</literal> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5589 module to indicate that the request was queued and the further processing |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5590 of this request should be postponed. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5591 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5592 --> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5593 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5594 </list> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5595 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5596 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5597 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5598 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5599 <literal>free(pc, data, state)</literal> — the method is called when an |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5600 upstream module has finished work with a particular server. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5601 The <literal>state</literal> argument is the status of upstream connection |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5602 completion. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5603 This is a bitmask, the following values may be set: |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5604 <literal>NGX_PEER_FAILED</literal> — this attempt is considered |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5605 <link doc="../http/ngx_http_upstream_module.xml" id="max_fails">unsuccessful</link>, |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5606 <literal>NGX_PEER_NEXT</literal> — a special case with codes 403 and 404 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5607 (see link above), which are not considered a failure. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5608 <literal>NGX_PEER_KEEPALIVE</literal>. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5609 Also, <literal>tries</literal> counter is decremented by this method. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5610 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5611 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5612 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5613 <literal>notify(pc, data, type)</literal> — currently unused |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5614 in the OSS version. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5615 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5616 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5617 <listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5618 <literal>set_session(pc, data)</literal> and |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5619 <literal>save_session(pc, data)</literal> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5620 — SSL-specific methods that allow to cache sessions to upstream |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5621 servers. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5622 The implementation is provided by the round-robin balancing method. |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5623 </listitem> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5624 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5625 </list> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5626 |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5627 </para> |
|
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5628 |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
5629 </section> |
|
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
5630 |
|
1939
c1b0169e8f54
Added the "Load balancing" section of the development guide.
Vladimir Homutov <vl@nginx.com>
parents:
1936
diff
changeset
|
5631 </section> |
|
1929
7f290929b32d
HTTP section of the development guide.
Roman Arutyunyan <arut@nginx.com>
parents:
1928
diff
changeset
|
5632 |
| 1899 | 5633 </article> |