1 /*-
2 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30
31 #include <sys/time.h>
32
33 #include <assert.h>
34 #include <stdlib.h>
35 #include <string.h>
36
37 #include "cachelib.h"
38 #include "debug.h"
39
40 #define INITIAL_ENTRIES_CAPACITY 32
41 #define ENTRIES_CAPACITY_STEP 32
42
43 #define STRING_SIMPLE_HASH_BODY(in_var, var, a, M) \
44 for ((var) = 0; *(in_var) != '\0'; ++(in_var)) \
45 (var) = ((a)*(var) + *(in_var)) % (M)
46
47 #define STRING_SIMPLE_MP2_HASH_BODY(in_var, var, a, M) \
48 for ((var) = 0; *(in_var) != 0; ++(in_var)) \
49 (var) = ((a)*(var) + *(in_var)) & (M - 1)
50
51 static int cache_elemsize_common_continue_func(struct cache_common_entry_ *,
52 struct cache_policy_item_ *);
53 static int cache_lifetime_common_continue_func(struct cache_common_entry_ *,
54 struct cache_policy_item_ *);
55 static void clear_cache_entry(struct cache_entry_ *);
56 static void destroy_cache_entry(struct cache_entry_ *);
57 static void destroy_cache_mp_read_session(struct cache_mp_read_session_ *);
58 static void destroy_cache_mp_write_session(struct cache_mp_write_session_ *);
59 static int entries_bsearch_cmp_func(const void *, const void *);
60 static int entries_qsort_cmp_func(const void *, const void *);
61 static struct cache_entry_ ** find_cache_entry_p(struct cache_ *,
62 const char *);
63 static void flush_cache_entry(struct cache_entry_ *);
64 static void flush_cache_policy(struct cache_common_entry_ *,
65 struct cache_policy_ *, struct cache_policy_ *,
66 int (*)(struct cache_common_entry_ *,
67 struct cache_policy_item_ *));
68 static int ht_items_cmp_func(const void *, const void *);
69 static int ht_items_fixed_size_left_cmp_func(const void *, const void *);
70 static hashtable_index_t ht_item_hash_func(const void *, size_t);
71
72 /*
73 * Hashing and comparing routines, that are used with the hash tables
74 */
75 static int
ht_items_cmp_func(const void * p1,const void * p2)76 ht_items_cmp_func(const void *p1, const void *p2)
77 {
78 struct cache_ht_item_data_ *hp1, *hp2;
79 size_t min_size;
80 int result;
81
82 hp1 = (struct cache_ht_item_data_ *)p1;
83 hp2 = (struct cache_ht_item_data_ *)p2;
84
85 assert(hp1->key != NULL);
86 assert(hp2->key != NULL);
87
88 if (hp1->key_size != hp2->key_size) {
89 min_size = (hp1->key_size < hp2->key_size) ? hp1->key_size :
90 hp2->key_size;
91 result = memcmp(hp1->key, hp2->key, min_size);
92
93 if (result == 0)
94 return ((hp1->key_size < hp2->key_size) ? -1 : 1);
95 else
96 return (result);
97 } else
98 return (memcmp(hp1->key, hp2->key, hp1->key_size));
99 }
100
101 static int
ht_items_fixed_size_left_cmp_func(const void * p1,const void * p2)102 ht_items_fixed_size_left_cmp_func(const void *p1, const void *p2)
103 {
104 struct cache_ht_item_data_ *hp1, *hp2;
105 size_t min_size;
106 int result;
107
108 hp1 = (struct cache_ht_item_data_ *)p1;
109 hp2 = (struct cache_ht_item_data_ *)p2;
110
111 assert(hp1->key != NULL);
112 assert(hp2->key != NULL);
113
114 if (hp1->key_size != hp2->key_size) {
115 min_size = (hp1->key_size < hp2->key_size) ? hp1->key_size :
116 hp2->key_size;
117 result = memcmp(hp1->key, hp2->key, min_size);
118
119 if (result == 0)
120 if (min_size == hp1->key_size)
121 return (0);
122 else
123 return ((hp1->key_size < hp2->key_size) ? -1 : 1);
124 else
125 return (result);
126 } else
127 return (memcmp(hp1->key, hp2->key, hp1->key_size));
128 }
129
130 static hashtable_index_t
ht_item_hash_func(const void * p,size_t cache_entries_size)131 ht_item_hash_func(const void *p, size_t cache_entries_size)
132 {
133 struct cache_ht_item_data_ *hp;
134 size_t i;
135
136 hashtable_index_t retval;
137
138 hp = (struct cache_ht_item_data_ *)p;
139 assert(hp->key != NULL);
140
141 retval = 0;
142 for (i = 0; i < hp->key_size; ++i)
143 retval = (127 * retval + (unsigned char)hp->key[i]) %
144 cache_entries_size;
145
146 return retval;
147 }
148
149 HASHTABLE_PROTOTYPE(cache_ht_, cache_ht_item_, struct cache_ht_item_data_);
150 HASHTABLE_GENERATE(cache_ht_, cache_ht_item_, struct cache_ht_item_data_, data,
151 ht_item_hash_func, ht_items_cmp_func);
152
153 /*
154 * Routines to sort and search the entries by name
155 */
156 static int
entries_bsearch_cmp_func(const void * key,const void * ent)157 entries_bsearch_cmp_func(const void *key, const void *ent)
158 {
159
160 assert(key != NULL);
161 assert(ent != NULL);
162
163 return (strcmp((char const *)key,
164 (*(struct cache_entry_ const **)ent)->name));
165 }
166
167 static int
entries_qsort_cmp_func(const void * e1,const void * e2)168 entries_qsort_cmp_func(const void *e1, const void *e2)
169 {
170
171 assert(e1 != NULL);
172 assert(e2 != NULL);
173
174 return (strcmp((*(struct cache_entry_ const **)e1)->name,
175 (*(struct cache_entry_ const **)e2)->name));
176 }
177
178 static struct cache_entry_ **
find_cache_entry_p(struct cache_ * the_cache,const char * entry_name)179 find_cache_entry_p(struct cache_ *the_cache, const char *entry_name)
180 {
181
182 return ((struct cache_entry_ **)(bsearch(entry_name, the_cache->entries,
183 the_cache->entries_size, sizeof(struct cache_entry_ *),
184 entries_bsearch_cmp_func)));
185 }
186
187 static void
destroy_cache_mp_write_session(struct cache_mp_write_session_ * ws)188 destroy_cache_mp_write_session(struct cache_mp_write_session_ *ws)
189 {
190
191 struct cache_mp_data_item_ *data_item;
192
193 TRACE_IN(destroy_cache_mp_write_session);
194 assert(ws != NULL);
195 while (!TAILQ_EMPTY(&ws->items)) {
196 data_item = TAILQ_FIRST(&ws->items);
197 TAILQ_REMOVE(&ws->items, data_item, entries);
198 free(data_item->value);
199 free(data_item);
200 }
201
202 free(ws);
203 TRACE_OUT(destroy_cache_mp_write_session);
204 }
205
206 static void
destroy_cache_mp_read_session(struct cache_mp_read_session_ * rs)207 destroy_cache_mp_read_session(struct cache_mp_read_session_ *rs)
208 {
209
210 TRACE_IN(destroy_cache_mp_read_session);
211 assert(rs != NULL);
212 free(rs);
213 TRACE_OUT(destroy_cache_mp_read_session);
214 }
215
216 static void
destroy_cache_entry(struct cache_entry_ * entry)217 destroy_cache_entry(struct cache_entry_ *entry)
218 {
219 struct cache_common_entry_ *common_entry;
220 struct cache_mp_entry_ *mp_entry;
221 struct cache_mp_read_session_ *rs;
222 struct cache_mp_write_session_ *ws;
223 struct cache_ht_item_ *ht_item;
224 struct cache_ht_item_data_ *ht_item_data;
225
226 TRACE_IN(destroy_cache_entry);
227 assert(entry != NULL);
228
229 if (entry->params->entry_type == CET_COMMON) {
230 common_entry = (struct cache_common_entry_ *)entry;
231
232 HASHTABLE_FOREACH(&(common_entry->items), ht_item) {
233 HASHTABLE_ENTRY_FOREACH(ht_item, data, ht_item_data)
234 {
235 free(ht_item_data->key);
236 free(ht_item_data->value);
237 }
238 HASHTABLE_ENTRY_CLEAR(ht_item, data);
239 }
240
241 HASHTABLE_DESTROY(&(common_entry->items), data);
242
243 /* FIFO policy is always first */
244 destroy_cache_fifo_policy(common_entry->policies[0]);
245 switch (common_entry->common_params.policy) {
246 case CPT_LRU:
247 destroy_cache_lru_policy(common_entry->policies[1]);
248 break;
249 case CPT_LFU:
250 destroy_cache_lfu_policy(common_entry->policies[1]);
251 break;
252 default:
253 break;
254 }
255 free(common_entry->policies);
256 } else {
257 mp_entry = (struct cache_mp_entry_ *)entry;
258
259 while (!TAILQ_EMPTY(&mp_entry->ws_head)) {
260 ws = TAILQ_FIRST(&mp_entry->ws_head);
261 TAILQ_REMOVE(&mp_entry->ws_head, ws, entries);
262 destroy_cache_mp_write_session(ws);
263 }
264
265 while (!TAILQ_EMPTY(&mp_entry->rs_head)) {
266 rs = TAILQ_FIRST(&mp_entry->rs_head);
267 TAILQ_REMOVE(&mp_entry->rs_head, rs, entries);
268 destroy_cache_mp_read_session(rs);
269 }
270
271 if (mp_entry->completed_write_session != NULL)
272 destroy_cache_mp_write_session(
273 mp_entry->completed_write_session);
274
275 if (mp_entry->pending_write_session != NULL)
276 destroy_cache_mp_write_session(
277 mp_entry->pending_write_session);
278 }
279
280 free(entry->name);
281 free(entry);
282 TRACE_OUT(destroy_cache_entry);
283 }
284
285 static void
clear_cache_entry(struct cache_entry_ * entry)286 clear_cache_entry(struct cache_entry_ *entry)
287 {
288 struct cache_mp_entry_ *mp_entry;
289 struct cache_common_entry_ *common_entry;
290 struct cache_ht_item_ *ht_item;
291 struct cache_ht_item_data_ *ht_item_data;
292 struct cache_policy_ *policy;
293 struct cache_policy_item_ *item, *next_item;
294 size_t entry_size;
295 unsigned int i;
296
297 if (entry->params->entry_type == CET_COMMON) {
298 common_entry = (struct cache_common_entry_ *)entry;
299
300 entry_size = 0;
301 HASHTABLE_FOREACH(&(common_entry->items), ht_item) {
302 HASHTABLE_ENTRY_FOREACH(ht_item, data, ht_item_data)
303 {
304 free(ht_item_data->key);
305 free(ht_item_data->value);
306 }
307 entry_size += HASHTABLE_ENTRY_SIZE(ht_item, data);
308 HASHTABLE_ENTRY_CLEAR(ht_item, data);
309 }
310
311 common_entry->items_size -= entry_size;
312 for (i = 0; i < common_entry->policies_size; ++i) {
313 policy = common_entry->policies[i];
314
315 next_item = NULL;
316 item = policy->get_first_item_func(policy);
317 while (item != NULL) {
318 next_item = policy->get_next_item_func(policy,
319 item);
320 policy->remove_item_func(policy, item);
321 policy->destroy_item_func(item);
322 item = next_item;
323 }
324 }
325 } else {
326 mp_entry = (struct cache_mp_entry_ *)entry;
327
328 if (mp_entry->rs_size == 0) {
329 if (mp_entry->completed_write_session != NULL) {
330 destroy_cache_mp_write_session(
331 mp_entry->completed_write_session);
332 mp_entry->completed_write_session = NULL;
333 }
334
335 memset(&mp_entry->creation_time, 0,
336 sizeof(struct timeval));
337 memset(&mp_entry->last_request_time, 0,
338 sizeof(struct timeval));
339 }
340 }
341 }
342
343 /*
344 * When passed to the flush_cache_policy, ensures that all old elements are
345 * deleted.
346 */
347 static int
cache_lifetime_common_continue_func(struct cache_common_entry_ * entry,struct cache_policy_item_ * item)348 cache_lifetime_common_continue_func(struct cache_common_entry_ *entry,
349 struct cache_policy_item_ *item)
350 {
351
352 return ((item->last_request_time.tv_sec - item->creation_time.tv_sec >
353 entry->common_params.max_lifetime.tv_sec) ? 1: 0);
354 }
355
356 /*
357 * When passed to the flush_cache_policy, ensures that all elements, that
358 * exceed the size limit, are deleted.
359 */
360 static int
cache_elemsize_common_continue_func(struct cache_common_entry_ * entry,struct cache_policy_item_ * item)361 cache_elemsize_common_continue_func(struct cache_common_entry_ *entry,
362 struct cache_policy_item_ *item)
363 {
364
365 return ((entry->items_size > entry->common_params.satisf_elemsize) ? 1
366 : 0);
367 }
368
369 /*
370 * Removes the elements from the cache entry, while the continue_func returns 1.
371 */
372 static void
flush_cache_policy(struct cache_common_entry_ * entry,struct cache_policy_ * policy,struct cache_policy_ * connected_policy,int (* continue_func)(struct cache_common_entry_ *,struct cache_policy_item_ *))373 flush_cache_policy(struct cache_common_entry_ *entry,
374 struct cache_policy_ *policy,
375 struct cache_policy_ *connected_policy,
376 int (*continue_func)(struct cache_common_entry_ *,
377 struct cache_policy_item_ *))
378 {
379 struct cache_policy_item_ *item, *next_item, *connected_item;
380 struct cache_ht_item_ *ht_item;
381 struct cache_ht_item_data_ *ht_item_data, ht_key;
382 hashtable_index_t hash;
383
384 assert(policy != NULL);
385
386 next_item = NULL;
387 item = policy->get_first_item_func(policy);
388 while ((item != NULL) && (continue_func(entry, item) == 1)) {
389 next_item = policy->get_next_item_func(policy, item);
390
391 connected_item = item->connected_item;
392 policy->remove_item_func(policy, item);
393
394 memset(&ht_key, 0, sizeof(struct cache_ht_item_data_));
395 ht_key.key = item->key;
396 ht_key.key_size = item->key_size;
397
398 hash = HASHTABLE_CALCULATE_HASH(cache_ht_, &entry->items,
399 &ht_key);
400 assert(hash < HASHTABLE_ENTRIES_COUNT(&entry->items));
401
402 ht_item = HASHTABLE_GET_ENTRY(&(entry->items), hash);
403 ht_item_data = HASHTABLE_ENTRY_FIND(cache_ht_, ht_item,
404 &ht_key);
405 assert(ht_item_data != NULL);
406 free(ht_item_data->key);
407 free(ht_item_data->value);
408 HASHTABLE_ENTRY_REMOVE(cache_ht_, ht_item, ht_item_data);
409 --entry->items_size;
410
411 policy->destroy_item_func(item);
412
413 if (connected_item != NULL) {
414 connected_policy->remove_item_func(connected_policy,
415 connected_item);
416 connected_policy->destroy_item_func(connected_item);
417 }
418
419 item = next_item;
420 }
421 }
422
423 static void
flush_cache_entry(struct cache_entry_ * entry)424 flush_cache_entry(struct cache_entry_ *entry)
425 {
426 struct cache_mp_entry_ *mp_entry;
427 struct cache_common_entry_ *common_entry;
428 struct cache_policy_ *policy, *connected_policy;
429
430 connected_policy = NULL;
431 if (entry->params->entry_type == CET_COMMON) {
432 common_entry = (struct cache_common_entry_ *)entry;
433 if ((common_entry->common_params.max_lifetime.tv_sec != 0) ||
434 (common_entry->common_params.max_lifetime.tv_usec != 0)) {
435
436 policy = common_entry->policies[0];
437 if (common_entry->policies_size > 1)
438 connected_policy = common_entry->policies[1];
439
440 flush_cache_policy(common_entry, policy,
441 connected_policy,
442 cache_lifetime_common_continue_func);
443 }
444
445
446 if ((common_entry->common_params.max_elemsize != 0) &&
447 common_entry->items_size >
448 common_entry->common_params.max_elemsize) {
449
450 if (common_entry->policies_size > 1) {
451 policy = common_entry->policies[1];
452 connected_policy = common_entry->policies[0];
453 } else {
454 policy = common_entry->policies[0];
455 connected_policy = NULL;
456 }
457
458 flush_cache_policy(common_entry, policy,
459 connected_policy,
460 cache_elemsize_common_continue_func);
461 }
462 } else {
463 mp_entry = (struct cache_mp_entry_ *)entry;
464
465 if ((mp_entry->mp_params.max_lifetime.tv_sec != 0)
466 || (mp_entry->mp_params.max_lifetime.tv_usec != 0)) {
467
468 if (mp_entry->last_request_time.tv_sec -
469 mp_entry->last_request_time.tv_sec >
470 mp_entry->mp_params.max_lifetime.tv_sec)
471 clear_cache_entry(entry);
472 }
473 }
474 }
475
476 struct cache_ *
init_cache(struct cache_params const * params)477 init_cache(struct cache_params const *params)
478 {
479 struct cache_ *retval;
480
481 TRACE_IN(init_cache);
482 assert(params != NULL);
483
484 retval = calloc(1, sizeof(*retval));
485 assert(retval != NULL);
486
487 assert(params != NULL);
488 memcpy(&retval->params, params, sizeof(struct cache_params));
489
490 retval->entries = calloc(1,
491 sizeof(*retval->entries) * INITIAL_ENTRIES_CAPACITY);
492 assert(retval->entries != NULL);
493
494 retval->entries_capacity = INITIAL_ENTRIES_CAPACITY;
495 retval->entries_size = 0;
496
497 TRACE_OUT(init_cache);
498 return (retval);
499 }
500
501 void
destroy_cache(struct cache_ * the_cache)502 destroy_cache(struct cache_ *the_cache)
503 {
504
505 TRACE_IN(destroy_cache);
506 assert(the_cache != NULL);
507
508 if (the_cache->entries != NULL) {
509 size_t i;
510 for (i = 0; i < the_cache->entries_size; ++i)
511 destroy_cache_entry(the_cache->entries[i]);
512
513 free(the_cache->entries);
514 }
515
516 free(the_cache);
517 TRACE_OUT(destroy_cache);
518 }
519
520 int
register_cache_entry(struct cache_ * the_cache,struct cache_entry_params const * params)521 register_cache_entry(struct cache_ *the_cache,
522 struct cache_entry_params const *params)
523 {
524 int policies_size;
525 size_t entry_name_size;
526 struct cache_common_entry_ *new_common_entry;
527 struct cache_mp_entry_ *new_mp_entry;
528
529 TRACE_IN(register_cache_entry);
530 assert(the_cache != NULL);
531
532 if (find_cache_entry(the_cache, params->entry_name) != NULL) {
533 TRACE_OUT(register_cache_entry);
534 return (-1);
535 }
536
537 if (the_cache->entries_size == the_cache->entries_capacity) {
538 struct cache_entry_ **new_entries;
539 size_t new_capacity;
540
541 new_capacity = the_cache->entries_capacity +
542 ENTRIES_CAPACITY_STEP;
543 new_entries = calloc(1,
544 sizeof(*new_entries) * new_capacity);
545 assert(new_entries != NULL);
546
547 memcpy(new_entries, the_cache->entries,
548 sizeof(struct cache_entry_ *)
549 * the_cache->entries_size);
550
551 free(the_cache->entries);
552 the_cache->entries = new_entries;
553 }
554
555 entry_name_size = strlen(params->entry_name) + 1;
556 switch (params->entry_type)
557 {
558 case CET_COMMON:
559 new_common_entry = calloc(1,
560 sizeof(*new_common_entry));
561 assert(new_common_entry != NULL);
562
563 memcpy(&new_common_entry->common_params, params,
564 sizeof(struct common_cache_entry_params));
565 new_common_entry->params =
566 (struct cache_entry_params *)&new_common_entry->common_params;
567
568 new_common_entry->common_params.cep.entry_name = calloc(1,
569 entry_name_size);
570 assert(new_common_entry->common_params.cep.entry_name != NULL);
571 strlcpy(new_common_entry->common_params.cep.entry_name,
572 params->entry_name, entry_name_size);
573 new_common_entry->name =
574 new_common_entry->common_params.cep.entry_name;
575
576 HASHTABLE_INIT(&(new_common_entry->items),
577 struct cache_ht_item_data_, data,
578 new_common_entry->common_params.cache_entries_size);
579
580 if (new_common_entry->common_params.policy == CPT_FIFO)
581 policies_size = 1;
582 else
583 policies_size = 2;
584
585 new_common_entry->policies = calloc(1,
586 sizeof(*new_common_entry->policies) * policies_size);
587 assert(new_common_entry->policies != NULL);
588
589 new_common_entry->policies_size = policies_size;
590 new_common_entry->policies[0] = init_cache_fifo_policy();
591
592 if (policies_size > 1) {
593 switch (new_common_entry->common_params.policy) {
594 case CPT_LRU:
595 new_common_entry->policies[1] =
596 init_cache_lru_policy();
597 break;
598 case CPT_LFU:
599 new_common_entry->policies[1] =
600 init_cache_lfu_policy();
601 break;
602 default:
603 break;
604 }
605 }
606
607 new_common_entry->get_time_func =
608 the_cache->params.get_time_func;
609 the_cache->entries[the_cache->entries_size++] =
610 (struct cache_entry_ *)new_common_entry;
611 break;
612 case CET_MULTIPART:
613 new_mp_entry = calloc(1,
614 sizeof(*new_mp_entry));
615 assert(new_mp_entry != NULL);
616
617 memcpy(&new_mp_entry->mp_params, params,
618 sizeof(struct mp_cache_entry_params));
619 new_mp_entry->params =
620 (struct cache_entry_params *)&new_mp_entry->mp_params;
621
622 new_mp_entry->mp_params.cep.entry_name = calloc(1,
623 entry_name_size);
624 assert(new_mp_entry->mp_params.cep.entry_name != NULL);
625 strlcpy(new_mp_entry->mp_params.cep.entry_name, params->entry_name,
626 entry_name_size);
627 new_mp_entry->name = new_mp_entry->mp_params.cep.entry_name;
628
629 TAILQ_INIT(&new_mp_entry->ws_head);
630 TAILQ_INIT(&new_mp_entry->rs_head);
631
632 new_mp_entry->get_time_func = the_cache->params.get_time_func;
633 the_cache->entries[the_cache->entries_size++] =
634 (struct cache_entry_ *)new_mp_entry;
635 break;
636 }
637
638
639 qsort(the_cache->entries, the_cache->entries_size,
640 sizeof(struct cache_entry_ *), entries_qsort_cmp_func);
641
642 TRACE_OUT(register_cache_entry);
643 return (0);
644 }
645
646 int
unregister_cache_entry(struct cache_ * the_cache,const char * entry_name)647 unregister_cache_entry(struct cache_ *the_cache, const char *entry_name)
648 {
649 struct cache_entry_ **del_ent;
650
651 TRACE_IN(unregister_cache_entry);
652 assert(the_cache != NULL);
653
654 del_ent = find_cache_entry_p(the_cache, entry_name);
655 if (del_ent != NULL) {
656 destroy_cache_entry(*del_ent);
657 --the_cache->entries_size;
658
659 memmove(del_ent, del_ent + 1,
660 (&(the_cache->entries[--the_cache->entries_size]) -
661 del_ent) * sizeof(struct cache_entry_ *));
662
663 TRACE_OUT(unregister_cache_entry);
664 return (0);
665 } else {
666 TRACE_OUT(unregister_cache_entry);
667 return (-1);
668 }
669 }
670
671 struct cache_entry_ *
find_cache_entry(struct cache_ * the_cache,const char * entry_name)672 find_cache_entry(struct cache_ *the_cache, const char *entry_name)
673 {
674 struct cache_entry_ **result;
675
676 TRACE_IN(find_cache_entry);
677 result = find_cache_entry_p(the_cache, entry_name);
678
679 if (result == NULL) {
680 TRACE_OUT(find_cache_entry);
681 return (NULL);
682 } else {
683 TRACE_OUT(find_cache_entry);
684 return (*result);
685 }
686 }
687
688 /*
689 * Tries to read the element with the specified key from the cache. If the
690 * value_size is too small, it will be filled with the proper number, and
691 * the user will need to call cache_read again with the value buffer, that
692 * is large enough.
693 * Function returns 0 on success, -1 on error, and -2 if the value_size is too
694 * small.
695 */
696 int
cache_read(struct cache_entry_ * entry,const char * key,size_t key_size,char * value,size_t * value_size)697 cache_read(struct cache_entry_ *entry, const char *key, size_t key_size,
698 char *value, size_t *value_size)
699 {
700 struct cache_common_entry_ *common_entry;
701 struct cache_ht_item_data_ item_data, *find_res;
702 struct cache_ht_item_ *item;
703 hashtable_index_t hash;
704 struct cache_policy_item_ *connected_item;
705
706 TRACE_IN(cache_read);
707 assert(entry != NULL);
708 assert(key != NULL);
709 assert(value_size != NULL);
710 assert(entry->params->entry_type == CET_COMMON);
711
712 common_entry = (struct cache_common_entry_ *)entry;
713
714 memset(&item_data, 0, sizeof(struct cache_ht_item_data_));
715 /* can't avoid the cast here */
716 item_data.key = (char *)key;
717 item_data.key_size = key_size;
718
719 hash = HASHTABLE_CALCULATE_HASH(cache_ht_, &common_entry->items,
720 &item_data);
721 assert(hash < HASHTABLE_ENTRIES_COUNT(&common_entry->items));
722
723 item = HASHTABLE_GET_ENTRY(&(common_entry->items), hash);
724 find_res = HASHTABLE_ENTRY_FIND(cache_ht_, item, &item_data);
725 if (find_res == NULL) {
726 TRACE_OUT(cache_read);
727 return (-1);
728 }
729 /* pretend that entry was not found if confidence is below threshold*/
730 if (find_res->confidence <
731 common_entry->common_params.confidence_threshold) {
732 TRACE_OUT(cache_read);
733 return (-1);
734 }
735
736 if ((common_entry->common_params.max_lifetime.tv_sec != 0) ||
737 (common_entry->common_params.max_lifetime.tv_usec != 0)) {
738
739 if (find_res->fifo_policy_item->last_request_time.tv_sec -
740 find_res->fifo_policy_item->creation_time.tv_sec >
741 common_entry->common_params.max_lifetime.tv_sec) {
742
743 free(find_res->key);
744 free(find_res->value);
745
746 connected_item =
747 find_res->fifo_policy_item->connected_item;
748 if (connected_item != NULL) {
749 common_entry->policies[1]->remove_item_func(
750 common_entry->policies[1],
751 connected_item);
752 common_entry->policies[1]->destroy_item_func(
753 connected_item);
754 }
755
756 common_entry->policies[0]->remove_item_func(
757 common_entry->policies[0],
758 find_res->fifo_policy_item);
759 common_entry->policies[0]->destroy_item_func(
760 find_res->fifo_policy_item);
761
762 HASHTABLE_ENTRY_REMOVE(cache_ht_, item, find_res);
763 --common_entry->items_size;
764 }
765 }
766
767 if ((*value_size < find_res->value_size) || (value == NULL)) {
768 *value_size = find_res->value_size;
769 TRACE_OUT(cache_read);
770 return (-2);
771 }
772
773 *value_size = find_res->value_size;
774 memcpy(value, find_res->value, find_res->value_size);
775
776 ++find_res->fifo_policy_item->request_count;
777 common_entry->get_time_func(
778 &find_res->fifo_policy_item->last_request_time);
779 common_entry->policies[0]->update_item_func(common_entry->policies[0],
780 find_res->fifo_policy_item);
781
782 if (find_res->fifo_policy_item->connected_item != NULL) {
783 connected_item = find_res->fifo_policy_item->connected_item;
784 memcpy(&connected_item->last_request_time,
785 &find_res->fifo_policy_item->last_request_time,
786 sizeof(struct timeval));
787 connected_item->request_count =
788 find_res->fifo_policy_item->request_count;
789
790 common_entry->policies[1]->update_item_func(
791 common_entry->policies[1], connected_item);
792 }
793
794 TRACE_OUT(cache_read);
795 return (0);
796 }
797
798 /*
799 * Writes the value with the specified key into the cache entry.
800 * Functions returns 0 on success, and -1 on error.
801 */
802 int
cache_write(struct cache_entry_ * entry,const char * key,size_t key_size,char const * value,size_t value_size)803 cache_write(struct cache_entry_ *entry, const char *key, size_t key_size,
804 char const *value, size_t value_size)
805 {
806 struct cache_common_entry_ *common_entry;
807 struct cache_ht_item_data_ item_data, *find_res;
808 struct cache_ht_item_ *item;
809 hashtable_index_t hash;
810
811 struct cache_policy_ *policy, *connected_policy;
812 struct cache_policy_item_ *policy_item;
813 struct cache_policy_item_ *connected_policy_item;
814
815 TRACE_IN(cache_write);
816 assert(entry != NULL);
817 assert(key != NULL);
818 assert(value != NULL);
819 assert(entry->params->entry_type == CET_COMMON);
820
821 common_entry = (struct cache_common_entry_ *)entry;
822
823 memset(&item_data, 0, sizeof(struct cache_ht_item_data_));
824 /* can't avoid the cast here */
825 item_data.key = (char *)key;
826 item_data.key_size = key_size;
827
828 hash = HASHTABLE_CALCULATE_HASH(cache_ht_, &common_entry->items,
829 &item_data);
830 assert(hash < HASHTABLE_ENTRIES_COUNT(&common_entry->items));
831
832 item = HASHTABLE_GET_ENTRY(&(common_entry->items), hash);
833 find_res = HASHTABLE_ENTRY_FIND(cache_ht_, item, &item_data);
834 if (find_res != NULL) {
835 if (find_res->confidence < common_entry->common_params.confidence_threshold) {
836 /* duplicate entry is no error, if confidence is low */
837 if ((find_res->value_size == value_size) &&
838 (memcmp(find_res->value, value, value_size) == 0)) {
839 /* increase confidence on exact match (key and values) */
840 find_res->confidence++;
841 } else {
842 /* create new entry with low confidence, if value changed */
843 free(item_data.value);
844 item_data.value = malloc(value_size);
845 assert(item_data.value != NULL);
846 memcpy(item_data.value, value, value_size);
847 item_data.value_size = value_size;
848 find_res->confidence = 1;
849 }
850 TRACE_OUT(cache_write);
851 return (0);
852 }
853 TRACE_OUT(cache_write);
854 return (-1);
855 }
856
857 item_data.key = malloc(key_size);
858 memcpy(item_data.key, key, key_size);
859
860 item_data.value = malloc(value_size);
861 assert(item_data.value != NULL);
862
863 memcpy(item_data.value, value, value_size);
864 item_data.value_size = value_size;
865
866 item_data.confidence = 1;
867
868 policy_item = common_entry->policies[0]->create_item_func();
869 policy_item->key = item_data.key;
870 policy_item->key_size = item_data.key_size;
871 common_entry->get_time_func(&policy_item->creation_time);
872
873 if (common_entry->policies_size > 1) {
874 connected_policy_item =
875 common_entry->policies[1]->create_item_func();
876 memcpy(&connected_policy_item->creation_time,
877 &policy_item->creation_time,
878 sizeof(struct timeval));
879 connected_policy_item->key = policy_item->key;
880 connected_policy_item->key_size = policy_item->key_size;
881
882 connected_policy_item->connected_item = policy_item;
883 policy_item->connected_item = connected_policy_item;
884 }
885
886 item_data.fifo_policy_item = policy_item;
887
888 common_entry->policies[0]->add_item_func(common_entry->policies[0],
889 policy_item);
890 if (common_entry->policies_size > 1)
891 common_entry->policies[1]->add_item_func(
892 common_entry->policies[1], connected_policy_item);
893
894 HASHTABLE_ENTRY_STORE(cache_ht_, item, &item_data);
895 ++common_entry->items_size;
896
897 if ((common_entry->common_params.max_elemsize != 0) &&
898 (common_entry->items_size >
899 common_entry->common_params.max_elemsize)) {
900 if (common_entry->policies_size > 1) {
901 policy = common_entry->policies[1];
902 connected_policy = common_entry->policies[0];
903 } else {
904 policy = common_entry->policies[0];
905 connected_policy = NULL;
906 }
907
908 flush_cache_policy(common_entry, policy, connected_policy,
909 cache_elemsize_common_continue_func);
910 }
911
912 TRACE_OUT(cache_write);
913 return (0);
914 }
915
916 /*
917 * Initializes the write session for the specified multipart entry. This
918 * session then should be filled with data either committed or abandoned by
919 * using close_cache_mp_write_session or abandon_cache_mp_write_session
920 * respectively.
921 * Returns NULL on errors (when there are too many opened write sessions for
922 * the entry).
923 */
924 struct cache_mp_write_session_ *
open_cache_mp_write_session(struct cache_entry_ * entry)925 open_cache_mp_write_session(struct cache_entry_ *entry)
926 {
927 struct cache_mp_entry_ *mp_entry;
928 struct cache_mp_write_session_ *retval;
929
930 TRACE_IN(open_cache_mp_write_session);
931 assert(entry != NULL);
932 assert(entry->params->entry_type == CET_MULTIPART);
933 mp_entry = (struct cache_mp_entry_ *)entry;
934
935 if ((mp_entry->mp_params.max_sessions > 0) &&
936 (mp_entry->ws_size == mp_entry->mp_params.max_sessions)) {
937 TRACE_OUT(open_cache_mp_write_session);
938 return (NULL);
939 }
940
941 retval = calloc(1,
942 sizeof(*retval));
943 assert(retval != NULL);
944
945 TAILQ_INIT(&retval->items);
946 retval->parent_entry = mp_entry;
947
948 TAILQ_INSERT_HEAD(&mp_entry->ws_head, retval, entries);
949 ++mp_entry->ws_size;
950
951 TRACE_OUT(open_cache_mp_write_session);
952 return (retval);
953 }
954
955 /*
956 * Writes data to the specified session. Return 0 on success and -1 on errors
957 * (when write session size limit is exceeded).
958 */
959 int
cache_mp_write(struct cache_mp_write_session_ * ws,char * data,size_t data_size)960 cache_mp_write(struct cache_mp_write_session_ *ws, char *data,
961 size_t data_size)
962 {
963 struct cache_mp_data_item_ *new_item;
964
965 TRACE_IN(cache_mp_write);
966 assert(ws != NULL);
967 assert(ws->parent_entry != NULL);
968 assert(ws->parent_entry->params->entry_type == CET_MULTIPART);
969
970 if ((ws->parent_entry->mp_params.max_elemsize > 0) &&
971 (ws->parent_entry->mp_params.max_elemsize == ws->items_size)) {
972 TRACE_OUT(cache_mp_write);
973 return (-1);
974 }
975
976 new_item = calloc(1,
977 sizeof(*new_item));
978 assert(new_item != NULL);
979
980 new_item->value = malloc(data_size);
981 assert(new_item->value != NULL);
982 memcpy(new_item->value, data, data_size);
983 new_item->value_size = data_size;
984
985 TAILQ_INSERT_TAIL(&ws->items, new_item, entries);
986 ++ws->items_size;
987
988 TRACE_OUT(cache_mp_write);
989 return (0);
990 }
991
992 /*
993 * Abandons the write session and frees all the connected resources.
994 */
995 void
abandon_cache_mp_write_session(struct cache_mp_write_session_ * ws)996 abandon_cache_mp_write_session(struct cache_mp_write_session_ *ws)
997 {
998
999 TRACE_IN(abandon_cache_mp_write_session);
1000 assert(ws != NULL);
1001 assert(ws->parent_entry != NULL);
1002 assert(ws->parent_entry->params->entry_type == CET_MULTIPART);
1003
1004 TAILQ_REMOVE(&ws->parent_entry->ws_head, ws, entries);
1005 --ws->parent_entry->ws_size;
1006
1007 destroy_cache_mp_write_session(ws);
1008 TRACE_OUT(abandon_cache_mp_write_session);
1009 }
1010
1011 /*
1012 * Commits the session to the entry, for which it was created.
1013 */
1014 void
close_cache_mp_write_session(struct cache_mp_write_session_ * ws)1015 close_cache_mp_write_session(struct cache_mp_write_session_ *ws)
1016 {
1017
1018 TRACE_IN(close_cache_mp_write_session);
1019 assert(ws != NULL);
1020 assert(ws->parent_entry != NULL);
1021 assert(ws->parent_entry->params->entry_type == CET_MULTIPART);
1022
1023 TAILQ_REMOVE(&ws->parent_entry->ws_head, ws, entries);
1024 --ws->parent_entry->ws_size;
1025
1026 if (ws->parent_entry->completed_write_session == NULL) {
1027 /*
1028 * If there is no completed session yet, this will be the one
1029 */
1030 ws->parent_entry->get_time_func(
1031 &ws->parent_entry->creation_time);
1032 ws->parent_entry->completed_write_session = ws;
1033 } else {
1034 /*
1035 * If there is a completed session, then we'll save our session
1036 * as a pending session. If there is already a pending session,
1037 * it would be destroyed.
1038 */
1039 if (ws->parent_entry->pending_write_session != NULL)
1040 destroy_cache_mp_write_session(
1041 ws->parent_entry->pending_write_session);
1042
1043 ws->parent_entry->pending_write_session = ws;
1044 }
1045 TRACE_OUT(close_cache_mp_write_session);
1046 }
1047
1048 /*
1049 * Opens read session for the specified entry. Returns NULL on errors (when
1050 * there are no data in the entry, or the data are obsolete).
1051 */
1052 struct cache_mp_read_session_ *
open_cache_mp_read_session(struct cache_entry_ * entry)1053 open_cache_mp_read_session(struct cache_entry_ *entry)
1054 {
1055 struct cache_mp_entry_ *mp_entry;
1056 struct cache_mp_read_session_ *retval;
1057
1058 TRACE_IN(open_cache_mp_read_session);
1059 assert(entry != NULL);
1060 assert(entry->params->entry_type == CET_MULTIPART);
1061 mp_entry = (struct cache_mp_entry_ *)entry;
1062
1063 if (mp_entry->completed_write_session == NULL) {
1064 TRACE_OUT(open_cache_mp_read_session);
1065 return (NULL);
1066 }
1067
1068 if ((mp_entry->mp_params.max_lifetime.tv_sec != 0)
1069 || (mp_entry->mp_params.max_lifetime.tv_usec != 0)) {
1070 if (mp_entry->last_request_time.tv_sec -
1071 mp_entry->last_request_time.tv_sec >
1072 mp_entry->mp_params.max_lifetime.tv_sec) {
1073 flush_cache_entry(entry);
1074 TRACE_OUT(open_cache_mp_read_session);
1075 return (NULL);
1076 }
1077 }
1078
1079 retval = calloc(1,
1080 sizeof(*retval));
1081 assert(retval != NULL);
1082
1083 retval->parent_entry = mp_entry;
1084 retval->current_item = TAILQ_FIRST(
1085 &mp_entry->completed_write_session->items);
1086
1087 TAILQ_INSERT_HEAD(&mp_entry->rs_head, retval, entries);
1088 ++mp_entry->rs_size;
1089
1090 mp_entry->get_time_func(&mp_entry->last_request_time);
1091 TRACE_OUT(open_cache_mp_read_session);
1092 return (retval);
1093 }
1094
1095 /*
1096 * Reads the data from the read session - step by step.
1097 * Returns 0 on success, -1 on error (when there are no more data), and -2 if
1098 * the data_size is too small. In the last case, data_size would be filled
1099 * the proper value.
1100 */
1101 int
cache_mp_read(struct cache_mp_read_session_ * rs,char * data,size_t * data_size)1102 cache_mp_read(struct cache_mp_read_session_ *rs, char *data, size_t *data_size)
1103 {
1104
1105 TRACE_IN(cache_mp_read);
1106 assert(rs != NULL);
1107
1108 if (rs->current_item == NULL) {
1109 TRACE_OUT(cache_mp_read);
1110 return (-1);
1111 }
1112
1113 if (rs->current_item->value_size > *data_size) {
1114 *data_size = rs->current_item->value_size;
1115 if (data == NULL) {
1116 TRACE_OUT(cache_mp_read);
1117 return (0);
1118 }
1119
1120 TRACE_OUT(cache_mp_read);
1121 return (-2);
1122 }
1123
1124 *data_size = rs->current_item->value_size;
1125 memcpy(data, rs->current_item->value, rs->current_item->value_size);
1126 rs->current_item = TAILQ_NEXT(rs->current_item, entries);
1127
1128 TRACE_OUT(cache_mp_read);
1129 return (0);
1130 }
1131
1132 /*
1133 * Closes the read session. If there are no more read sessions and there is
1134 * a pending write session, it will be committed and old
1135 * completed_write_session will be destroyed.
1136 */
1137 void
close_cache_mp_read_session(struct cache_mp_read_session_ * rs)1138 close_cache_mp_read_session(struct cache_mp_read_session_ *rs)
1139 {
1140
1141 TRACE_IN(close_cache_mp_read_session);
1142 assert(rs != NULL);
1143 assert(rs->parent_entry != NULL);
1144
1145 TAILQ_REMOVE(&rs->parent_entry->rs_head, rs, entries);
1146 --rs->parent_entry->rs_size;
1147
1148 if ((rs->parent_entry->rs_size == 0) &&
1149 (rs->parent_entry->pending_write_session != NULL)) {
1150 destroy_cache_mp_write_session(
1151 rs->parent_entry->completed_write_session);
1152 rs->parent_entry->completed_write_session =
1153 rs->parent_entry->pending_write_session;
1154 rs->parent_entry->pending_write_session = NULL;
1155 }
1156
1157 destroy_cache_mp_read_session(rs);
1158 TRACE_OUT(close_cache_mp_read_session);
1159 }
1160
1161 int
transform_cache_entry(struct cache_entry_ * entry,enum cache_transformation_t transformation)1162 transform_cache_entry(struct cache_entry_ *entry,
1163 enum cache_transformation_t transformation)
1164 {
1165
1166 TRACE_IN(transform_cache_entry);
1167 switch (transformation) {
1168 case CTT_CLEAR:
1169 clear_cache_entry(entry);
1170 TRACE_OUT(transform_cache_entry);
1171 return (0);
1172 case CTT_FLUSH:
1173 flush_cache_entry(entry);
1174 TRACE_OUT(transform_cache_entry);
1175 return (0);
1176 default:
1177 TRACE_OUT(transform_cache_entry);
1178 return (-1);
1179 }
1180 }
1181
1182 int
transform_cache_entry_part(struct cache_entry_ * entry,enum cache_transformation_t transformation,const char * key_part,size_t key_part_size,enum part_position_t part_position)1183 transform_cache_entry_part(struct cache_entry_ *entry,
1184 enum cache_transformation_t transformation, const char *key_part,
1185 size_t key_part_size, enum part_position_t part_position)
1186 {
1187 struct cache_common_entry_ *common_entry;
1188 struct cache_ht_item_ *ht_item;
1189 struct cache_ht_item_data_ *ht_item_data, ht_key;
1190
1191 struct cache_policy_item_ *item, *connected_item;
1192
1193 TRACE_IN(transform_cache_entry_part);
1194 if (entry->params->entry_type != CET_COMMON) {
1195 TRACE_OUT(transform_cache_entry_part);
1196 return (-1);
1197 }
1198
1199 if (transformation != CTT_CLEAR) {
1200 TRACE_OUT(transform_cache_entry_part);
1201 return (-1);
1202 }
1203
1204 memset(&ht_key, 0, sizeof(struct cache_ht_item_data_));
1205 ht_key.key = (char *)key_part; /* can't avoid casting here */
1206 ht_key.key_size = key_part_size;
1207
1208 common_entry = (struct cache_common_entry_ *)entry;
1209 HASHTABLE_FOREACH(&(common_entry->items), ht_item) {
1210 do {
1211 ht_item_data = HASHTABLE_ENTRY_FIND_SPECIAL(cache_ht_,
1212 ht_item, &ht_key,
1213 ht_items_fixed_size_left_cmp_func);
1214
1215 if (ht_item_data != NULL) {
1216 item = ht_item_data->fifo_policy_item;
1217 connected_item = item->connected_item;
1218
1219 common_entry->policies[0]->remove_item_func(
1220 common_entry->policies[0],
1221 item);
1222
1223 free(ht_item_data->key);
1224 free(ht_item_data->value);
1225 HASHTABLE_ENTRY_REMOVE(cache_ht_, ht_item,
1226 ht_item_data);
1227 --common_entry->items_size;
1228
1229 common_entry->policies[0]->destroy_item_func(
1230 item);
1231 if (common_entry->policies_size == 2) {
1232 common_entry->policies[1]->remove_item_func(
1233 common_entry->policies[1],
1234 connected_item);
1235 common_entry->policies[1]->destroy_item_func(
1236 connected_item);
1237 }
1238 }
1239 } while (ht_item_data != NULL);
1240 }
1241
1242 TRACE_OUT(transform_cache_entry_part);
1243 return (0);
1244 }
1245