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comparison src/http/modules/ngx_http_degradation_module.c @ 546:e19e5f542878 NGINX_0_8_25

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nginx 0.8.25 *) Change: now no message is written in an error log if a variable is not found by $r->variable() method. *) Feature: the ngx_http_degradation_module. *) Feature: regular expression named captures. *) Feature: now URI part is not required a "proxy_pass" directive if variables are used. *) Feature: now the "msie_padding" directive works for Chrome too. *) Bugfix: a segmentation fault occurred in a worker process on low memory condition; the bug had appeared in 0.8.18. *) Bugfix: nginx sent gzipped responses to clients those do not support gzip, if "gzip_static on" and "gzip_vary off"; the bug had appeared in 0.8.16.
author Igor Sysoev <http://sysoev.ru>
date Mon, 16 Nov 2009 00:00:00 +0300
parents
children 2da4537168f8
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545:91e4b06e1a01 546:e19e5f542878
1
2 /*
3 * Copyright (C) Igor Sysoev
4 */
5
6
7 #include <ngx_config.h>
8 #include <ngx_core.h>
9 #include <ngx_http.h>
10
11
12 typedef struct {
13 size_t sbrk_size;
14 } ngx_http_degradation_main_conf_t;
15
16
17 typedef struct {
18 ngx_uint_t degrade;
19 } ngx_http_degradation_loc_conf_t;
20
21
22 static ngx_conf_enum_t ngx_http_degrade[] = {
23 { ngx_string("204"), 204 },
24 { ngx_string("444"), 444 },
25 { ngx_null_string, 0 }
26 };
27
28
29 static void *ngx_http_degradation_create_main_conf(ngx_conf_t *cf);
30 static void *ngx_http_degradation_create_loc_conf(ngx_conf_t *cf);
31 static char *ngx_http_degradation_merge_loc_conf(ngx_conf_t *cf, void *parent,
32 void *child);
33 static char *ngx_http_degradation(ngx_conf_t *cf, ngx_command_t *cmd,
34 void *conf);
35 static ngx_int_t ngx_http_degradation_init(ngx_conf_t *cf);
36
37
38 static ngx_command_t ngx_http_degradation_commands[] = {
39
40 { ngx_string("degradation"),
41 NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1,
42 ngx_http_degradation,
43 NGX_HTTP_MAIN_CONF_OFFSET,
44 0,
45 NULL },
46
47 { ngx_string("degrade"),
48 NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
49 ngx_conf_set_enum_slot,
50 NGX_HTTP_LOC_CONF_OFFSET,
51 offsetof(ngx_http_degradation_loc_conf_t, degrade),
52 &ngx_http_degrade },
53
54 ngx_null_command
55 };
56
57
58 static ngx_http_module_t ngx_http_degradation_module_ctx = {
59 NULL, /* preconfiguration */
60 ngx_http_degradation_init, /* postconfiguration */
61
62 ngx_http_degradation_create_main_conf, /* create main configuration */
63 NULL, /* init main configuration */
64
65 NULL, /* create server configuration */
66 NULL, /* merge server configuration */
67
68 ngx_http_degradation_create_loc_conf, /* create location configuration */
69 ngx_http_degradation_merge_loc_conf /* merge location configuration */
70 };
71
72
73 ngx_module_t ngx_http_degradation_module = {
74 NGX_MODULE_V1,
75 &ngx_http_degradation_module_ctx, /* module context */
76 ngx_http_degradation_commands, /* module directives */
77 NGX_HTTP_MODULE, /* module type */
78 NULL, /* init master */
79 NULL, /* init module */
80 NULL, /* init process */
81 NULL, /* init thread */
82 NULL, /* exit thread */
83 NULL, /* exit process */
84 NULL, /* exit master */
85 NGX_MODULE_V1_PADDING
86 };
87
88
89 static ngx_int_t
90 ngx_http_degradation_handler(ngx_http_request_t *r)
91 {
92 time_t now;
93 static size_t sbrk_size;
94 static time_t sbrk_time;
95 ngx_http_degradation_loc_conf_t *dlcf;
96 ngx_http_degradation_main_conf_t *dmcf;
97
98 dlcf = ngx_http_get_module_loc_conf(r, ngx_http_degradation_module);
99
100 if (dlcf->degrade == 0) {
101 return NGX_DECLINED;
102 }
103
104 dmcf = ngx_http_get_module_main_conf(r, ngx_http_degradation_module);
105
106 if (dmcf->sbrk_size) {
107
108 now = ngx_time();
109
110 /* lock mutex */
111
112 if (now != sbrk_time) {
113
114 /*
115 * ELF/i386 is loaded at 0x08000000, 128M
116 * ELF/amd64 is loaded at 0x00400000, 4M
117 *
118 * use a function address to substract the loading address
119 */
120
121 sbrk_size = (size_t) sbrk(0) - ((uintptr_t) ngx_palloc & ~0x3FFFFF);
122 sbrk_time = now;
123 }
124
125 /* unlock mutex */
126
127 if (sbrk_size >= dmcf->sbrk_size) {
128 ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
129 "degradation sbrk: %uz", sbrk_size);
130
131 return dlcf->degrade;
132 }
133 }
134
135 return NGX_DECLINED;
136 }
137
138
139 static void *
140 ngx_http_degradation_create_main_conf(ngx_conf_t *cf)
141 {
142 ngx_http_degradation_main_conf_t *dmcf;
143
144 dmcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_degradation_main_conf_t));
145 if (dmcf == NULL) {
146 return NULL;
147 }
148
149 return dmcf;
150 }
151
152
153 static void *
154 ngx_http_degradation_create_loc_conf(ngx_conf_t *cf)
155 {
156 ngx_http_degradation_loc_conf_t *conf;
157
158 conf = ngx_palloc(cf->pool, sizeof(ngx_http_degradation_loc_conf_t));
159 if (conf == NULL) {
160 return NULL;
161 }
162
163 conf->degrade = NGX_CONF_UNSET_UINT;
164
165 return conf;
166 }
167
168
169 static char *
170 ngx_http_degradation_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
171 {
172 ngx_http_degradation_loc_conf_t *prev = parent;
173 ngx_http_degradation_loc_conf_t *conf = child;
174
175 ngx_conf_merge_uint_value(conf->degrade, prev->degrade, 0);
176
177 return NGX_CONF_OK;
178 }
179
180
181 static char *
182 ngx_http_degradation(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
183 {
184 ngx_http_degradation_main_conf_t *dmcf = conf;
185
186 ngx_str_t *value, s;
187
188 value = cf->args->elts;
189
190 if (ngx_strncmp(value[1].data, "sbrk=", 5) == 0) {
191
192 s.len = value[1].len - 5;
193 s.data = value[1].data + 5;
194
195 dmcf->sbrk_size = ngx_parse_size(&s);
196 if (dmcf->sbrk_size == (size_t) NGX_ERROR) {
197 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
198 "invalid sbrk size \"%V\"", &value[1]);
199 return NGX_CONF_ERROR;
200 }
201 }
202
203 return NGX_CONF_OK;
204 }
205
206
207 static ngx_int_t
208 ngx_http_degradation_init(ngx_conf_t *cf)
209 {
210 ngx_http_handler_pt *h;
211 ngx_http_core_main_conf_t *cmcf;
212
213 cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);
214
215 h = ngx_array_push(&cmcf->phases[NGX_HTTP_PREACCESS_PHASE].handlers);
216 if (h == NULL) {
217 return NGX_ERROR;
218 }
219
220 *h = ngx_http_degradation_handler;
221
222 return NGX_OK;
223 }