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comparison src/core/ngx_open_file_cache.c @ 1453:f2feed5bffe1

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open file cache
author Igor Sysoev <igor@sysoev.ru>
date Sat, 01 Sep 2007 12:11:21 +0000
parents
children 223e92651ca5
comparison
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1452:cd586e963db0 1453:f2feed5bffe1
1
2 /*
3 * Copyright (C) Igor Sysoev
4 */
5
6
7 #include <ngx_config.h>
8 #include <ngx_core.h>
9 #include <ngx_event.h>
10
11
12 /*
13 * open file cache caches
14 * open file handles with stat() info;
15 * directories stat() info;
16 * files and directories errors: not found, access denied, etc.
17 */
18
19
20 static void ngx_open_file_cache_cleanup(void *data);
21 static void ngx_open_file_cleanup(void *data);
22 static void ngx_close_cached_file(ngx_open_file_cache_t *cache,
23 ngx_cached_open_file_t *file, ngx_log_t *log);
24 static ngx_int_t ngx_open_and_stat_file(u_char *name, ngx_open_file_info_t *of,
25 ngx_log_t *log);
26 static void ngx_expire_old_cached_files(ngx_open_file_cache_t *cache,
27 ngx_uint_t n, ngx_log_t *log);
28 static void ngx_open_file_cache_rbtree_insert_value(ngx_rbtree_node_t *temp,
29 ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel);
30 static void ngx_open_file_cache_remove(ngx_event_t *ev);
31
32
33 ngx_open_file_cache_t *
34 ngx_open_file_cache_init(ngx_pool_t *pool, ngx_uint_t max, time_t inactive)
35 {
36 ngx_rbtree_node_t *sentinel;
37 ngx_pool_cleanup_t *cln;
38 ngx_open_file_cache_t *cache;
39
40 cache = ngx_palloc(pool, sizeof(ngx_open_file_cache_t));
41 if (cache == NULL) {
42 return NULL;
43 }
44
45 cache->list_head.prev = NULL;
46 cache->list_head.next = &cache->list_tail;
47
48 cache->list_tail.prev = &cache->list_head;
49 cache->list_tail.next = NULL;
50
51 sentinel = ngx_palloc(pool, sizeof(ngx_rbtree_node_t));
52 if (sentinel == NULL) {
53 return NULL;
54 }
55
56 ngx_rbtree_sentinel_init(sentinel);
57
58 cache->rbtree.root = sentinel;
59 cache->rbtree.sentinel = sentinel;
60 cache->rbtree.insert = ngx_open_file_cache_rbtree_insert_value;
61
62 cache->current = 0;
63 cache->max = max;
64 cache->inactive = inactive;
65
66 cln = ngx_pool_cleanup_add(pool, 0);
67 if (cln == NULL) {
68 return NULL;
69 }
70
71 cln->handler = ngx_open_file_cache_cleanup;
72 cln->data = cache;
73
74 return cache;
75 }
76
77
78 static void
79 ngx_open_file_cache_cleanup(void *data)
80 {
81 ngx_open_file_cache_t *cache = data;
82
83 ngx_cached_open_file_t *file;
84
85 ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0,
86 "open file cache cleanup");
87
88 for ( ;; ) {
89
90 file = cache->list_tail.prev;
91
92 if (file == &cache->list_head) {
93 break;
94 }
95
96 file->next->prev = file->prev;
97 file->prev->next = file->next;
98
99 ngx_rbtree_delete(&cache->rbtree, &file->node);
100
101 cache->current--;
102
103 ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0,
104 "delete cached open file: %s", file->name);
105
106 if (!file->err && !file->is_dir) {
107 file->close = 1;
108 file->count = 0;
109 ngx_close_cached_file(cache, file, ngx_cycle->log);
110
111 } else {
112 ngx_free(file->name);
113 ngx_free(file);
114 }
115 }
116
117 if (cache->current) {
118 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
119 "%d items still leave in open file cache",
120 cache->current);
121 }
122
123 if (cache->rbtree.root != cache->rbtree.sentinel) {
124 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
125 "rbtree still is not empty in open file cache");
126
127 }
128 }
129
130
131 ngx_int_t
132 ngx_open_cached_file(ngx_open_file_cache_t *cache, ngx_str_t *name,
133 ngx_open_file_info_t *of, ngx_pool_t *pool)
134 {
135 time_t now;
136 uint32_t hash;
137 ngx_int_t rc;
138 ngx_rbtree_node_t *node, *sentinel;
139 ngx_pool_cleanup_t *cln;
140 ngx_cached_open_file_t *file;
141 ngx_pool_cleanup_file_t *clnf;
142 ngx_open_file_cache_event_t *fev;
143 ngx_open_file_cache_cleanup_t *ofcln;
144
145 of->err = 0;
146
147 if (cache == NULL) {
148
149 cln = ngx_pool_cleanup_add(pool, sizeof(ngx_pool_cleanup_file_t));
150 if (cln == NULL) {
151 return NGX_ERROR;
152 }
153
154 rc = ngx_open_and_stat_file(name->data, of, pool->log);
155
156 if (rc == NGX_OK && !of->is_dir) {
157 cln->handler = ngx_pool_cleanup_file;
158 clnf = cln->data;
159
160 clnf->fd = of->fd;
161 clnf->name = name->data;
162 clnf->log = pool->log;
163 }
164
165 return rc;
166 }
167
168 cln = ngx_pool_cleanup_add(pool, sizeof(ngx_open_file_cache_cleanup_t));
169 if (cln == NULL) {
170 return NGX_ERROR;
171 }
172
173 hash = ngx_crc32_long(name->data, name->len);
174
175 node = cache->rbtree.root;
176 sentinel = cache->rbtree.sentinel;
177
178 now = ngx_time();
179
180 while (node != sentinel) {
181
182 if (hash < node->key) {
183 node = node->left;
184 continue;
185 }
186
187 if (hash > node->key) {
188 node = node->right;
189 continue;
190 }
191
192 /* hash == node->key */
193
194 do {
195 file = (ngx_cached_open_file_t *) node;
196
197 rc = ngx_strcmp(name->data, file->name);
198
199 if (rc == 0) {
200
201 file->next->prev = file->prev;
202 file->prev->next = file->next;
203
204 if (file->event || now - file->created < of->retest) {
205 if (file->err == 0) {
206 of->fd = file->fd;
207 of->uniq = file->uniq;
208 of->mtime = file->mtime;
209 of->size = file->size;
210
211 of->is_dir = file->is_dir;
212 of->is_file = file->is_file;
213 of->is_link = file->is_link;
214 of->is_exec = file->is_exec;
215
216 if (!file->is_dir) {
217 file->count++;
218 }
219
220 } else {
221 of->err = file->err;
222 }
223
224 goto found;
225 }
226
227 ngx_log_debug4(NGX_LOG_DEBUG_CORE, pool->log, 0,
228 "retest open file: %s, fd:%d, c:%d, e:%d",
229 file->name, file->fd, file->count, file->err);
230
231 if (file->is_dir) {
232
233 /*
234 * chances that directory became file are very small
235 * so test_dir flag allows to use a single ngx_file_info()
236 * syscall instead of three syscalls
237 */
238
239 of->test_dir = 1;
240 }
241
242 rc = ngx_open_and_stat_file(name->data, of, pool->log);
243
244 if (rc != NGX_OK && (of->err == 0 || !of->errors)) {
245 goto failed;
246 }
247
248 if (of->is_dir) {
249 if (file->is_dir || file->err) {
250 goto update;
251 }
252
253 /* file became directory */
254
255 } else if (of->err == 0) { /* file */
256
257 if (file->is_dir || file->err) {
258 goto update;
259 }
260
261 if (of->uniq == file->uniq
262 && of->mtime == file->mtime
263 && of->size == file->size)
264 {
265 if (ngx_close_file(of->fd) == NGX_FILE_ERROR) {
266 ngx_log_error(NGX_LOG_ALERT, pool->log, ngx_errno,
267 ngx_close_file_n " \"%s\" failed",
268 name->data);
269 }
270
271 of->fd = file->fd;
272 file->count++;
273
274 goto renew;
275 }
276
277 /* file was changed */
278
279 } else { /* error to cache */
280
281 if (file->err || file->is_dir) {
282 goto update;
283 }
284
285 /* file was removed, etc. */
286 }
287
288 if (file->count == 0) {
289 if (ngx_close_file(file->fd) == NGX_FILE_ERROR) {
290 ngx_log_error(NGX_LOG_ALERT, pool->log, ngx_errno,
291 ngx_close_file_n " \"%s\" failed",
292 name->data);
293 }
294
295 goto update;
296 }
297
298 ngx_rbtree_delete(&cache->rbtree, &file->node);
299
300 cache->current--;
301
302 file->close = 1;
303
304 goto create;
305 }
306
307 node = (rc < 0) ? node->left : node->right;
308
309 } while (node != sentinel && hash == node->key);
310
311 break;
312 }
313
314 /* not found */
315
316 file = NULL;
317
318 rc = ngx_open_and_stat_file(name->data, of, pool->log);
319
320 if (rc != NGX_OK && (of->err == 0 || !of->errors)) {
321 goto failed;
322 }
323
324 create:
325
326 if (cache->current >= cache->max) {
327 ngx_expire_old_cached_files(cache, 0, pool->log);
328 }
329
330 file = ngx_alloc(sizeof(ngx_cached_open_file_t), pool->log);
331
332 if (file == NULL) {
333 goto failed;
334 }
335
336 file->name = ngx_alloc(name->len + 1, pool->log);
337
338 if (file->name == NULL) {
339 ngx_free(file);
340 file = NULL;
341 goto failed;
342 }
343
344 ngx_cpystrn(file->name, name->data, name->len + 1);
345
346 file->node.key = hash;
347
348 ngx_rbtree_insert(&cache->rbtree, &file->node);
349
350 cache->current++;
351
352 file->count = 0;
353
354 update:
355
356 if (ngx_event_flags & NGX_USE_VNODE_EVENT && of->fd != NGX_INVALID_FILE) {
357
358 file->event = ngx_calloc(sizeof(ngx_event_t), pool->log);
359 if (file->event== NULL) {
360 goto failed;
361 }
362
363 fev = ngx_alloc(sizeof(ngx_open_file_cache_event_t), pool->log);
364 if (fev == NULL) {
365 goto failed;
366 }
367
368 fev->fd = of->fd;
369 fev->file = file;
370 fev->cache = cache;
371
372 file->event->handler = ngx_open_file_cache_remove;
373 file->event->data = fev;
374
375 /*
376 * although vnode event may be called while ngx_cycle->poll
377 * destruction; however, cleanup procedures are run before any
378 * memory freeing and events will be canceled.
379 */
380
381 file->event->log = ngx_cycle->log;
382
383 if (ngx_add_event(file->event, NGX_VNODE_EVENT, NGX_ONESHOT_EVENT)
384 != NGX_OK)
385 {
386 ngx_free(file->event->data);
387 ngx_free(file->event);
388 goto failed;
389 }
390
391 } else {
392 file->event = NULL;
393 }
394
395 file->fd = of->fd;
396 file->err = of->err;
397
398 if (of->err == 0) {
399 file->uniq = of->uniq;
400 file->mtime = of->mtime;
401 file->size = of->size;
402
403 file->close = 0;
404
405 file->is_dir = of->is_dir;
406 file->is_file = of->is_file;
407 file->is_link = of->is_link;
408 file->is_exec = of->is_exec;
409
410 if (!of->is_dir) {
411 file->count++;
412 }
413 }
414
415 renew:
416
417 file->created = now;
418
419 found:
420
421 file->accessed = now;
422
423 /* add to the inactive list head */
424
425 file->next = cache->list_head.next;
426 file->next->prev = file;
427 file->prev = &cache->list_head;
428 cache->list_head.next = file;
429
430 ngx_log_debug4(NGX_LOG_DEBUG_CORE, pool->log, 0,
431 "cached open file: %s, fd:%d, c:%d, e:%d",
432 file->name, file->fd, file->count, file->err);
433
434 if (of->err == 0) {
435
436 if (!of->is_dir) {
437 cln->handler = ngx_open_file_cleanup;
438 ofcln = cln->data;
439
440 ofcln->cache = cache;
441 ofcln->file = file;
442 ofcln->log = pool->log;
443 }
444
445 return NGX_OK;
446 }
447
448 return NGX_ERROR;
449
450 failed:
451
452 if (file && file->count == 0) {
453 ngx_rbtree_delete(&cache->rbtree, &file->node);
454
455 cache->current--;
456
457 if (ngx_close_file(file->fd) == NGX_FILE_ERROR) {
458 ngx_log_error(NGX_LOG_ALERT, pool->log, ngx_errno,
459 ngx_close_file_n " \"%s\" failed", file->name);
460 }
461
462 ngx_free(file->name);
463 ngx_free(file);
464 }
465
466 if (of->fd != NGX_INVALID_FILE) {
467 if (ngx_close_file(of->fd) == NGX_FILE_ERROR) {
468 ngx_log_error(NGX_LOG_ALERT, pool->log, ngx_errno,
469 ngx_close_file_n " \"%s\" failed", name->data);
470 }
471 }
472
473 return NGX_ERROR;
474 }
475
476
477 static ngx_int_t
478 ngx_open_and_stat_file(u_char *name, ngx_open_file_info_t *of, ngx_log_t *log)
479 {
480 ngx_fd_t fd;
481 ngx_file_info_t fi;
482
483 of->fd = NGX_INVALID_FILE;
484
485 if (of->test_dir) {
486
487 if (ngx_file_info(name, &fi) == -1) {
488 of->err = ngx_errno;
489
490 return NGX_ERROR;
491 }
492
493 of->uniq = ngx_file_uniq(&fi);
494 of->mtime = ngx_file_mtime(&fi);
495 of->size = ngx_file_size(&fi);
496 of->is_dir = ngx_is_dir(&fi);
497 of->is_file = ngx_is_file(&fi);
498 of->is_link = ngx_is_link(&fi);
499 of->is_exec = ngx_is_exec(&fi);
500
501 if (of->is_dir) {
502 return NGX_OK;
503 }
504 }
505
506 fd = ngx_open_file(name, NGX_FILE_RDONLY, NGX_FILE_OPEN, 0);
507
508 if (fd == NGX_INVALID_FILE) {
509 of->err = ngx_errno;
510 return NGX_ERROR;
511 }
512
513 if (ngx_fd_info(fd, &fi) == NGX_FILE_ERROR) {
514 ngx_log_error(NGX_LOG_CRIT, log, ngx_errno,
515 ngx_fd_info_n " \"%s\" failed", name);
516
517 if (ngx_close_file(fd) == NGX_FILE_ERROR) {
518 ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
519 ngx_close_file_n " \"%s\" failed", name);
520 }
521
522 return NGX_ERROR;
523 }
524
525 if (ngx_is_dir(&fi)) {
526 if (ngx_close_file(fd) == NGX_FILE_ERROR) {
527 ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
528 ngx_close_file_n " \"%s\" failed", name);
529 }
530
531 fd = NGX_INVALID_FILE;
532 }
533
534 of->fd = fd;
535 of->uniq = ngx_file_uniq(&fi);
536 of->mtime = ngx_file_mtime(&fi);
537 of->size = ngx_file_size(&fi);
538 of->is_dir = ngx_is_dir(&fi);
539 of->is_file = ngx_is_file(&fi);
540 of->is_link = ngx_is_link(&fi);
541 of->is_exec = ngx_is_exec(&fi);
542
543 return NGX_OK;
544 }
545
546
547 static void
548 ngx_open_file_cleanup(void *data)
549 {
550 ngx_open_file_cache_cleanup_t *c = data;
551
552 c->file->count--;
553
554 ngx_close_cached_file(c->cache, c->file, c->log);
555
556 /* drop one or two expired open files */
557 ngx_expire_old_cached_files(c->cache, 1, c->log);
558 }
559
560
561 static void
562 ngx_close_cached_file(ngx_open_file_cache_t *cache,
563 ngx_cached_open_file_t *file, ngx_log_t *log)
564 {
565 ngx_log_debug4(NGX_LOG_DEBUG_CORE, log, 0,
566 "close cached open file: %s, fd:%d, c:%d, %d",
567 file->name, file->fd, file->count, file->close);
568
569 if (!file->close) {
570
571 file->accessed = ngx_time();
572
573 if (cache->list_head.next != file) {
574
575 /* delete from inactive list */
576
577 file->next->prev = file->prev;
578 file->prev->next = file->next;
579
580 /* add to the inactive list head */
581
582 file->next = cache->list_head.next;
583 file->next->prev = file;
584 file->prev = &cache->list_head;
585 cache->list_head.next = file;
586 }
587
588 return;
589 }
590
591 if (file->event) {
592 (void) ngx_del_event(file->event, NGX_VNODE_EVENT,
593 file->count ? NGX_FLUSH_EVENT : NGX_CLOSE_EVENT);
594
595 ngx_free(file->event->data);
596 ngx_free(file->event);
597 file->event = NULL;
598 }
599
600 if (file->count) {
601 return;
602 }
603
604 if (ngx_close_file(file->fd) == NGX_FILE_ERROR) {
605 ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
606 ngx_close_file_n " \"%s\" failed", file->name);
607 }
608
609 ngx_free(file->name);
610 ngx_free(file);
611 }
612
613
614 static void
615 ngx_expire_old_cached_files(ngx_open_file_cache_t *cache, ngx_uint_t n,
616 ngx_log_t *log)
617 {
618 time_t now;
619 ngx_cached_open_file_t *file;
620
621 now = ngx_time();
622
623 /*
624 * n == 1 deletes one or two inactive files
625 * n == 0 deletes least recently used file by force
626 * and one or two inactive files
627 */
628
629 while (n < 3) {
630
631 file = cache->list_tail.prev;
632
633 if (file == &cache->list_head) {
634 return;
635 }
636
637 if (n++ != 0 && now - file->accessed <= cache->inactive) {
638 return;
639 }
640
641 file->next->prev = file->prev;
642 file->prev->next = file->next;
643
644 ngx_rbtree_delete(&cache->rbtree, &file->node);
645
646 cache->current--;
647
648 ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0,
649 "expire cached open file: %s", file->name);
650
651 if (!file->err && !file->is_dir) {
652 file->close = 1;
653 ngx_close_cached_file(cache, file, log);
654
655 } else {
656 ngx_free(file->name);
657 ngx_free(file);
658 }
659 }
660 }
661
662
663 static void
664 ngx_open_file_cache_rbtree_insert_value(ngx_rbtree_node_t *temp,
665 ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel)
666 {
667 ngx_rbtree_node_t **p;
668 ngx_cached_open_file_t *file, *file_temp;
669
670 for ( ;; ) {
671
672 if (node->key < temp->key) {
673
674 p = &temp->left;
675
676 } else if (node->key > temp->key) {
677
678 p = &temp->right;
679
680 } else { /* node->key == temp->key */
681
682 file = (ngx_cached_open_file_t *) node;
683 file_temp = (ngx_cached_open_file_t *) temp;
684
685 p = (ngx_strcmp(file->name, file_temp->name) < 0)
686 ? &temp->left : &temp->right;
687 }
688
689 if (*p == sentinel) {
690 break;
691 }
692
693 temp = *p;
694 }
695
696 *p = node;
697 node->parent = temp;
698 node->left = sentinel;
699 node->right = sentinel;
700 ngx_rbt_red(node);
701 }
702
703
704 static void
705 ngx_open_file_cache_remove(ngx_event_t *ev)
706 {
707 ngx_cached_open_file_t *file;
708 ngx_open_file_cache_event_t *fev;
709
710 fev = ev->data;
711 file = fev->file;
712
713 file->next->prev = file->prev;
714 file->prev->next = file->next;
715
716 ngx_rbtree_delete(&fev->cache->rbtree, &file->node);
717
718 fev->cache->current--;
719
720 /* NGX_ONESHOT_EVENT was already deleted */
721 file->event = NULL;
722
723 file->close = 1;
724
725 ngx_close_cached_file(fev->cache, file, ev->log);
726
727 /* free memory only when fev->cache and fev->file are already not needed */
728
729 ngx_free(ev->data);
730 ngx_free(ev);
731 }