2 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
28 #include <sys/cdefs.h>
38 #define INITIAL_ENTRIES_CAPACITY 32
39 #define ENTRIES_CAPACITY_STEP 32
41 #define STRING_SIMPLE_HASH_BODY(in_var, var, a, M) \
42 for ((var) = 0; *(in_var) != '\0'; ++(in_var)) \
43 (var) = ((a)*(var) + *(in_var)) % (M)
45 #define STRING_SIMPLE_MP2_HASH_BODY(in_var, var, a, M) \
46 for ((var) = 0; *(in_var) != 0; ++(in_var)) \
47 (var) = ((a)*(var) + *(in_var)) & (M - 1)
49 static int cache_elemsize_common_continue_func(struct cache_common_entry_ *,
50 struct cache_policy_item_ *);
51 static int cache_lifetime_common_continue_func(struct cache_common_entry_ *,
52 struct cache_policy_item_ *);
53 static void clear_cache_entry(struct cache_entry_ *);
54 static void destroy_cache_entry(struct cache_entry_ *);
55 static void destroy_cache_mp_read_session(struct cache_mp_read_session_ *);
56 static void destroy_cache_mp_write_session(struct cache_mp_write_session_ *);
57 static int entries_bsearch_cmp_func(const void *, const void *);
58 static int entries_qsort_cmp_func(const void *, const void *);
59 static struct cache_entry_ ** find_cache_entry_p(struct cache_ *,
61 static void flush_cache_entry(struct cache_entry_ *);
62 static void flush_cache_policy(struct cache_common_entry_ *,
63 struct cache_policy_ *, struct cache_policy_ *,
64 int (*)(struct cache_common_entry_ *,
65 struct cache_policy_item_ *));
66 static int ht_items_cmp_func(const void *, const void *);
67 static int ht_items_fixed_size_left_cmp_func(const void *, const void *);
68 static hashtable_index_t ht_item_hash_func(const void *, size_t);
71 * Hashing and comparing routines, that are used with the hash tables
74 ht_items_cmp_func(const void *p1, const void *p2)
76 struct cache_ht_item_data_ *hp1, *hp2;
80 hp1 = (struct cache_ht_item_data_ *)p1;
81 hp2 = (struct cache_ht_item_data_ *)p2;
83 assert(hp1->key != NULL);
84 assert(hp2->key != NULL);
86 if (hp1->key_size != hp2->key_size) {
87 min_size = (hp1->key_size < hp2->key_size) ? hp1->key_size :
89 result = memcmp(hp1->key, hp2->key, min_size);
92 return ((hp1->key_size < hp2->key_size) ? -1 : 1);
96 return (memcmp(hp1->key, hp2->key, hp1->key_size));
100 ht_items_fixed_size_left_cmp_func(const void *p1, const void *p2)
102 struct cache_ht_item_data_ *hp1, *hp2;
106 hp1 = (struct cache_ht_item_data_ *)p1;
107 hp2 = (struct cache_ht_item_data_ *)p2;
109 assert(hp1->key != NULL);
110 assert(hp2->key != NULL);
112 if (hp1->key_size != hp2->key_size) {
113 min_size = (hp1->key_size < hp2->key_size) ? hp1->key_size :
115 result = memcmp(hp1->key, hp2->key, min_size);
118 if (min_size == hp1->key_size)
121 return ((hp1->key_size < hp2->key_size) ? -1 : 1);
125 return (memcmp(hp1->key, hp2->key, hp1->key_size));
128 static hashtable_index_t
129 ht_item_hash_func(const void *p, size_t cache_entries_size)
131 struct cache_ht_item_data_ *hp;
134 hashtable_index_t retval;
136 hp = (struct cache_ht_item_data_ *)p;
137 assert(hp->key != NULL);
140 for (i = 0; i < hp->key_size; ++i)
141 retval = (127 * retval + (unsigned char)hp->key[i]) %
147 HASHTABLE_PROTOTYPE(cache_ht_, cache_ht_item_, struct cache_ht_item_data_);
148 HASHTABLE_GENERATE(cache_ht_, cache_ht_item_, struct cache_ht_item_data_, data,
149 ht_item_hash_func, ht_items_cmp_func);
152 * Routines to sort and search the entries by name
155 entries_bsearch_cmp_func(const void *key, const void *ent)
161 return (strcmp((char const *)key,
162 (*(struct cache_entry_ const **)ent)->name));
166 entries_qsort_cmp_func(const void *e1, const void *e2)
172 return (strcmp((*(struct cache_entry_ const **)e1)->name,
173 (*(struct cache_entry_ const **)e2)->name));
176 static struct cache_entry_ **
177 find_cache_entry_p(struct cache_ *the_cache, const char *entry_name)
180 return ((struct cache_entry_ **)(bsearch(entry_name, the_cache->entries,
181 the_cache->entries_size, sizeof(struct cache_entry_ *),
182 entries_bsearch_cmp_func)));
186 destroy_cache_mp_write_session(struct cache_mp_write_session_ *ws)
189 struct cache_mp_data_item_ *data_item;
191 TRACE_IN(destroy_cache_mp_write_session);
193 while (!TAILQ_EMPTY(&ws->items)) {
194 data_item = TAILQ_FIRST(&ws->items);
195 TAILQ_REMOVE(&ws->items, data_item, entries);
196 free(data_item->value);
201 TRACE_OUT(destroy_cache_mp_write_session);
205 destroy_cache_mp_read_session(struct cache_mp_read_session_ *rs)
208 TRACE_IN(destroy_cache_mp_read_session);
211 TRACE_OUT(destroy_cache_mp_read_session);
215 destroy_cache_entry(struct cache_entry_ *entry)
217 struct cache_common_entry_ *common_entry;
218 struct cache_mp_entry_ *mp_entry;
219 struct cache_mp_read_session_ *rs;
220 struct cache_mp_write_session_ *ws;
221 struct cache_ht_item_ *ht_item;
222 struct cache_ht_item_data_ *ht_item_data;
224 TRACE_IN(destroy_cache_entry);
225 assert(entry != NULL);
227 if (entry->params->entry_type == CET_COMMON) {
228 common_entry = (struct cache_common_entry_ *)entry;
230 HASHTABLE_FOREACH(&(common_entry->items), ht_item) {
231 HASHTABLE_ENTRY_FOREACH(ht_item, data, ht_item_data)
233 free(ht_item_data->key);
234 free(ht_item_data->value);
236 HASHTABLE_ENTRY_CLEAR(ht_item, data);
239 HASHTABLE_DESTROY(&(common_entry->items), data);
241 /* FIFO policy is always first */
242 destroy_cache_fifo_policy(common_entry->policies[0]);
243 switch (common_entry->common_params.policy) {
245 destroy_cache_lru_policy(common_entry->policies[1]);
248 destroy_cache_lfu_policy(common_entry->policies[1]);
253 free(common_entry->policies);
255 mp_entry = (struct cache_mp_entry_ *)entry;
257 while (!TAILQ_EMPTY(&mp_entry->ws_head)) {
258 ws = TAILQ_FIRST(&mp_entry->ws_head);
259 TAILQ_REMOVE(&mp_entry->ws_head, ws, entries);
260 destroy_cache_mp_write_session(ws);
263 while (!TAILQ_EMPTY(&mp_entry->rs_head)) {
264 rs = TAILQ_FIRST(&mp_entry->rs_head);
265 TAILQ_REMOVE(&mp_entry->rs_head, rs, entries);
266 destroy_cache_mp_read_session(rs);
269 if (mp_entry->completed_write_session != NULL)
270 destroy_cache_mp_write_session(
271 mp_entry->completed_write_session);
273 if (mp_entry->pending_write_session != NULL)
274 destroy_cache_mp_write_session(
275 mp_entry->pending_write_session);
280 TRACE_OUT(destroy_cache_entry);
284 clear_cache_entry(struct cache_entry_ *entry)
286 struct cache_mp_entry_ *mp_entry;
287 struct cache_common_entry_ *common_entry;
288 struct cache_ht_item_ *ht_item;
289 struct cache_ht_item_data_ *ht_item_data;
290 struct cache_policy_ *policy;
291 struct cache_policy_item_ *item, *next_item;
295 if (entry->params->entry_type == CET_COMMON) {
296 common_entry = (struct cache_common_entry_ *)entry;
299 HASHTABLE_FOREACH(&(common_entry->items), ht_item) {
300 HASHTABLE_ENTRY_FOREACH(ht_item, data, ht_item_data)
302 free(ht_item_data->key);
303 free(ht_item_data->value);
305 entry_size += HASHTABLE_ENTRY_SIZE(ht_item, data);
306 HASHTABLE_ENTRY_CLEAR(ht_item, data);
309 common_entry->items_size -= entry_size;
310 for (i = 0; i < common_entry->policies_size; ++i) {
311 policy = common_entry->policies[i];
314 item = policy->get_first_item_func(policy);
315 while (item != NULL) {
316 next_item = policy->get_next_item_func(policy,
318 policy->remove_item_func(policy, item);
319 policy->destroy_item_func(item);
324 mp_entry = (struct cache_mp_entry_ *)entry;
326 if (mp_entry->rs_size == 0) {
327 if (mp_entry->completed_write_session != NULL) {
328 destroy_cache_mp_write_session(
329 mp_entry->completed_write_session);
330 mp_entry->completed_write_session = NULL;
333 memset(&mp_entry->creation_time, 0,
334 sizeof(struct timeval));
335 memset(&mp_entry->last_request_time, 0,
336 sizeof(struct timeval));
342 * When passed to the flush_cache_policy, ensures that all old elements are
346 cache_lifetime_common_continue_func(struct cache_common_entry_ *entry,
347 struct cache_policy_item_ *item)
350 return ((item->last_request_time.tv_sec - item->creation_time.tv_sec >
351 entry->common_params.max_lifetime.tv_sec) ? 1: 0);
355 * When passed to the flush_cache_policy, ensures that all elements, that
356 * exceed the size limit, are deleted.
359 cache_elemsize_common_continue_func(struct cache_common_entry_ *entry,
360 struct cache_policy_item_ *item)
363 return ((entry->items_size > entry->common_params.satisf_elemsize) ? 1
368 * Removes the elements from the cache entry, while the continue_func returns 1.
371 flush_cache_policy(struct cache_common_entry_ *entry,
372 struct cache_policy_ *policy,
373 struct cache_policy_ *connected_policy,
374 int (*continue_func)(struct cache_common_entry_ *,
375 struct cache_policy_item_ *))
377 struct cache_policy_item_ *item, *next_item, *connected_item;
378 struct cache_ht_item_ *ht_item;
379 struct cache_ht_item_data_ *ht_item_data, ht_key;
380 hashtable_index_t hash;
382 assert(policy != NULL);
385 item = policy->get_first_item_func(policy);
386 while ((item != NULL) && (continue_func(entry, item) == 1)) {
387 next_item = policy->get_next_item_func(policy, item);
389 connected_item = item->connected_item;
390 policy->remove_item_func(policy, item);
392 memset(&ht_key, 0, sizeof(struct cache_ht_item_data_));
393 ht_key.key = item->key;
394 ht_key.key_size = item->key_size;
396 hash = HASHTABLE_CALCULATE_HASH(cache_ht_, &entry->items,
398 assert(hash < HASHTABLE_ENTRIES_COUNT(&entry->items));
400 ht_item = HASHTABLE_GET_ENTRY(&(entry->items), hash);
401 ht_item_data = HASHTABLE_ENTRY_FIND(cache_ht_, ht_item,
403 assert(ht_item_data != NULL);
404 free(ht_item_data->key);
405 free(ht_item_data->value);
406 HASHTABLE_ENTRY_REMOVE(cache_ht_, ht_item, ht_item_data);
409 policy->destroy_item_func(item);
411 if (connected_item != NULL) {
412 connected_policy->remove_item_func(connected_policy,
414 connected_policy->destroy_item_func(connected_item);
422 flush_cache_entry(struct cache_entry_ *entry)
424 struct cache_mp_entry_ *mp_entry;
425 struct cache_common_entry_ *common_entry;
426 struct cache_policy_ *policy, *connected_policy;
428 connected_policy = NULL;
429 if (entry->params->entry_type == CET_COMMON) {
430 common_entry = (struct cache_common_entry_ *)entry;
431 if ((common_entry->common_params.max_lifetime.tv_sec != 0) ||
432 (common_entry->common_params.max_lifetime.tv_usec != 0)) {
434 policy = common_entry->policies[0];
435 if (common_entry->policies_size > 1)
436 connected_policy = common_entry->policies[1];
438 flush_cache_policy(common_entry, policy,
440 cache_lifetime_common_continue_func);
444 if ((common_entry->common_params.max_elemsize != 0) &&
445 common_entry->items_size >
446 common_entry->common_params.max_elemsize) {
448 if (common_entry->policies_size > 1) {
449 policy = common_entry->policies[1];
450 connected_policy = common_entry->policies[0];
452 policy = common_entry->policies[0];
453 connected_policy = NULL;
456 flush_cache_policy(common_entry, policy,
458 cache_elemsize_common_continue_func);
461 mp_entry = (struct cache_mp_entry_ *)entry;
463 if ((mp_entry->mp_params.max_lifetime.tv_sec != 0)
464 || (mp_entry->mp_params.max_lifetime.tv_usec != 0)) {
466 if (mp_entry->last_request_time.tv_sec -
467 mp_entry->last_request_time.tv_sec >
468 mp_entry->mp_params.max_lifetime.tv_sec)
469 clear_cache_entry(entry);
475 init_cache(struct cache_params const *params)
477 struct cache_ *retval;
479 TRACE_IN(init_cache);
480 assert(params != NULL);
482 retval = calloc(1, sizeof(*retval));
483 assert(retval != NULL);
485 assert(params != NULL);
486 memcpy(&retval->params, params, sizeof(struct cache_params));
488 retval->entries = calloc(INITIAL_ENTRIES_CAPACITY,
489 sizeof(*retval->entries));
490 assert(retval->entries != NULL);
492 retval->entries_capacity = INITIAL_ENTRIES_CAPACITY;
493 retval->entries_size = 0;
495 TRACE_OUT(init_cache);
500 destroy_cache(struct cache_ *the_cache)
503 TRACE_IN(destroy_cache);
504 assert(the_cache != NULL);
506 if (the_cache->entries != NULL) {
508 for (i = 0; i < the_cache->entries_size; ++i)
509 destroy_cache_entry(the_cache->entries[i]);
511 free(the_cache->entries);
515 TRACE_OUT(destroy_cache);
519 register_cache_entry(struct cache_ *the_cache,
520 struct cache_entry_params const *params)
523 size_t entry_name_size;
524 struct cache_common_entry_ *new_common_entry;
525 struct cache_mp_entry_ *new_mp_entry;
527 TRACE_IN(register_cache_entry);
528 assert(the_cache != NULL);
530 if (find_cache_entry(the_cache, params->entry_name) != NULL) {
531 TRACE_OUT(register_cache_entry);
535 if (the_cache->entries_size == the_cache->entries_capacity) {
536 struct cache_entry_ **new_entries;
539 new_capacity = the_cache->entries_capacity +
540 ENTRIES_CAPACITY_STEP;
541 new_entries = calloc(new_capacity,
542 sizeof(*new_entries));
543 assert(new_entries != NULL);
545 memcpy(new_entries, the_cache->entries,
546 sizeof(struct cache_entry_ *)
547 * the_cache->entries_size);
549 free(the_cache->entries);
550 the_cache->entries = new_entries;
553 entry_name_size = strlen(params->entry_name) + 1;
554 switch (params->entry_type)
557 new_common_entry = calloc(1,
558 sizeof(*new_common_entry));
559 assert(new_common_entry != NULL);
561 memcpy(&new_common_entry->common_params, params,
562 sizeof(struct common_cache_entry_params));
563 new_common_entry->params =
564 (struct cache_entry_params *)&new_common_entry->common_params;
566 new_common_entry->common_params.cep.entry_name = calloc(1,
568 assert(new_common_entry->common_params.cep.entry_name != NULL);
569 strlcpy(new_common_entry->common_params.cep.entry_name,
570 params->entry_name, entry_name_size);
571 new_common_entry->name =
572 new_common_entry->common_params.cep.entry_name;
574 HASHTABLE_INIT(&(new_common_entry->items),
575 struct cache_ht_item_data_, data,
576 new_common_entry->common_params.cache_entries_size);
578 if (new_common_entry->common_params.policy == CPT_FIFO)
583 new_common_entry->policies = calloc(policies_size,
584 sizeof(*new_common_entry->policies));
585 assert(new_common_entry->policies != NULL);
587 new_common_entry->policies_size = policies_size;
588 new_common_entry->policies[0] = init_cache_fifo_policy();
590 if (policies_size > 1) {
591 switch (new_common_entry->common_params.policy) {
593 new_common_entry->policies[1] =
594 init_cache_lru_policy();
597 new_common_entry->policies[1] =
598 init_cache_lfu_policy();
605 new_common_entry->get_time_func =
606 the_cache->params.get_time_func;
607 the_cache->entries[the_cache->entries_size++] =
608 (struct cache_entry_ *)new_common_entry;
611 new_mp_entry = calloc(1,
612 sizeof(*new_mp_entry));
613 assert(new_mp_entry != NULL);
615 memcpy(&new_mp_entry->mp_params, params,
616 sizeof(struct mp_cache_entry_params));
617 new_mp_entry->params =
618 (struct cache_entry_params *)&new_mp_entry->mp_params;
620 new_mp_entry->mp_params.cep.entry_name = calloc(1,
622 assert(new_mp_entry->mp_params.cep.entry_name != NULL);
623 strlcpy(new_mp_entry->mp_params.cep.entry_name, params->entry_name,
625 new_mp_entry->name = new_mp_entry->mp_params.cep.entry_name;
627 TAILQ_INIT(&new_mp_entry->ws_head);
628 TAILQ_INIT(&new_mp_entry->rs_head);
630 new_mp_entry->get_time_func = the_cache->params.get_time_func;
631 the_cache->entries[the_cache->entries_size++] =
632 (struct cache_entry_ *)new_mp_entry;
637 qsort(the_cache->entries, the_cache->entries_size,
638 sizeof(struct cache_entry_ *), entries_qsort_cmp_func);
640 TRACE_OUT(register_cache_entry);
645 unregister_cache_entry(struct cache_ *the_cache, const char *entry_name)
647 struct cache_entry_ **del_ent;
649 TRACE_IN(unregister_cache_entry);
650 assert(the_cache != NULL);
652 del_ent = find_cache_entry_p(the_cache, entry_name);
653 if (del_ent != NULL) {
654 destroy_cache_entry(*del_ent);
655 --the_cache->entries_size;
657 memmove(del_ent, del_ent + 1,
658 (&(the_cache->entries[--the_cache->entries_size]) -
659 del_ent) * sizeof(struct cache_entry_ *));
661 TRACE_OUT(unregister_cache_entry);
664 TRACE_OUT(unregister_cache_entry);
669 struct cache_entry_ *
670 find_cache_entry(struct cache_ *the_cache, const char *entry_name)
672 struct cache_entry_ **result;
674 TRACE_IN(find_cache_entry);
675 result = find_cache_entry_p(the_cache, entry_name);
677 if (result == NULL) {
678 TRACE_OUT(find_cache_entry);
681 TRACE_OUT(find_cache_entry);
687 * Tries to read the element with the specified key from the cache. If the
688 * value_size is too small, it will be filled with the proper number, and
689 * the user will need to call cache_read again with the value buffer, that
691 * Function returns 0 on success, -1 on error, and -2 if the value_size is too
695 cache_read(struct cache_entry_ *entry, const char *key, size_t key_size,
696 char *value, size_t *value_size)
698 struct cache_common_entry_ *common_entry;
699 struct cache_ht_item_data_ item_data, *find_res;
700 struct cache_ht_item_ *item;
701 hashtable_index_t hash;
702 struct cache_policy_item_ *connected_item;
704 TRACE_IN(cache_read);
705 assert(entry != NULL);
707 assert(value_size != NULL);
708 assert(entry->params->entry_type == CET_COMMON);
710 common_entry = (struct cache_common_entry_ *)entry;
712 memset(&item_data, 0, sizeof(struct cache_ht_item_data_));
713 /* can't avoid the cast here */
714 item_data.key = (char *)key;
715 item_data.key_size = key_size;
717 hash = HASHTABLE_CALCULATE_HASH(cache_ht_, &common_entry->items,
719 assert(hash < HASHTABLE_ENTRIES_COUNT(&common_entry->items));
721 item = HASHTABLE_GET_ENTRY(&(common_entry->items), hash);
722 find_res = HASHTABLE_ENTRY_FIND(cache_ht_, item, &item_data);
723 if (find_res == NULL) {
724 TRACE_OUT(cache_read);
727 /* pretend that entry was not found if confidence is below threshold*/
728 if (find_res->confidence <
729 common_entry->common_params.confidence_threshold) {
730 TRACE_OUT(cache_read);
734 if ((common_entry->common_params.max_lifetime.tv_sec != 0) ||
735 (common_entry->common_params.max_lifetime.tv_usec != 0)) {
737 if (find_res->fifo_policy_item->last_request_time.tv_sec -
738 find_res->fifo_policy_item->creation_time.tv_sec >
739 common_entry->common_params.max_lifetime.tv_sec) {
742 free(find_res->value);
745 find_res->fifo_policy_item->connected_item;
746 if (connected_item != NULL) {
747 common_entry->policies[1]->remove_item_func(
748 common_entry->policies[1],
750 common_entry->policies[1]->destroy_item_func(
754 common_entry->policies[0]->remove_item_func(
755 common_entry->policies[0],
756 find_res->fifo_policy_item);
757 common_entry->policies[0]->destroy_item_func(
758 find_res->fifo_policy_item);
760 HASHTABLE_ENTRY_REMOVE(cache_ht_, item, find_res);
761 --common_entry->items_size;
765 if ((*value_size < find_res->value_size) || (value == NULL)) {
766 *value_size = find_res->value_size;
767 TRACE_OUT(cache_read);
771 *value_size = find_res->value_size;
772 memcpy(value, find_res->value, find_res->value_size);
774 ++find_res->fifo_policy_item->request_count;
775 common_entry->get_time_func(
776 &find_res->fifo_policy_item->last_request_time);
777 common_entry->policies[0]->update_item_func(common_entry->policies[0],
778 find_res->fifo_policy_item);
780 if (find_res->fifo_policy_item->connected_item != NULL) {
781 connected_item = find_res->fifo_policy_item->connected_item;
782 memcpy(&connected_item->last_request_time,
783 &find_res->fifo_policy_item->last_request_time,
784 sizeof(struct timeval));
785 connected_item->request_count =
786 find_res->fifo_policy_item->request_count;
788 common_entry->policies[1]->update_item_func(
789 common_entry->policies[1], connected_item);
792 TRACE_OUT(cache_read);
797 * Writes the value with the specified key into the cache entry.
798 * Functions returns 0 on success, and -1 on error.
801 cache_write(struct cache_entry_ *entry, const char *key, size_t key_size,
802 char const *value, size_t value_size)
804 struct cache_common_entry_ *common_entry;
805 struct cache_ht_item_data_ item_data, *find_res;
806 struct cache_ht_item_ *item;
807 hashtable_index_t hash;
809 struct cache_policy_ *policy, *connected_policy;
810 struct cache_policy_item_ *policy_item;
811 struct cache_policy_item_ *connected_policy_item;
813 TRACE_IN(cache_write);
814 assert(entry != NULL);
816 assert(value != NULL);
817 assert(entry->params->entry_type == CET_COMMON);
819 common_entry = (struct cache_common_entry_ *)entry;
821 memset(&item_data, 0, sizeof(struct cache_ht_item_data_));
822 /* can't avoid the cast here */
823 item_data.key = (char *)key;
824 item_data.key_size = key_size;
826 hash = HASHTABLE_CALCULATE_HASH(cache_ht_, &common_entry->items,
828 assert(hash < HASHTABLE_ENTRIES_COUNT(&common_entry->items));
830 item = HASHTABLE_GET_ENTRY(&(common_entry->items), hash);
831 find_res = HASHTABLE_ENTRY_FIND(cache_ht_, item, &item_data);
832 if (find_res != NULL) {
833 if (find_res->confidence < common_entry->common_params.confidence_threshold) {
834 /* duplicate entry is no error, if confidence is low */
835 if ((find_res->value_size == value_size) &&
836 (memcmp(find_res->value, value, value_size) == 0)) {
837 /* increase confidence on exact match (key and values) */
838 find_res->confidence++;
840 /* create new entry with low confidence, if value changed */
841 free(item_data.value);
842 item_data.value = malloc(value_size);
843 assert(item_data.value != NULL);
844 memcpy(item_data.value, value, value_size);
845 item_data.value_size = value_size;
846 find_res->confidence = 1;
848 TRACE_OUT(cache_write);
851 TRACE_OUT(cache_write);
855 item_data.key = malloc(key_size);
856 memcpy(item_data.key, key, key_size);
858 item_data.value = malloc(value_size);
859 assert(item_data.value != NULL);
861 memcpy(item_data.value, value, value_size);
862 item_data.value_size = value_size;
864 item_data.confidence = 1;
866 policy_item = common_entry->policies[0]->create_item_func();
867 policy_item->key = item_data.key;
868 policy_item->key_size = item_data.key_size;
869 common_entry->get_time_func(&policy_item->creation_time);
871 if (common_entry->policies_size > 1) {
872 connected_policy_item =
873 common_entry->policies[1]->create_item_func();
874 memcpy(&connected_policy_item->creation_time,
875 &policy_item->creation_time,
876 sizeof(struct timeval));
877 connected_policy_item->key = policy_item->key;
878 connected_policy_item->key_size = policy_item->key_size;
880 connected_policy_item->connected_item = policy_item;
881 policy_item->connected_item = connected_policy_item;
884 item_data.fifo_policy_item = policy_item;
886 common_entry->policies[0]->add_item_func(common_entry->policies[0],
888 if (common_entry->policies_size > 1)
889 common_entry->policies[1]->add_item_func(
890 common_entry->policies[1], connected_policy_item);
892 HASHTABLE_ENTRY_STORE(cache_ht_, item, &item_data);
893 ++common_entry->items_size;
895 if ((common_entry->common_params.max_elemsize != 0) &&
896 (common_entry->items_size >
897 common_entry->common_params.max_elemsize)) {
898 if (common_entry->policies_size > 1) {
899 policy = common_entry->policies[1];
900 connected_policy = common_entry->policies[0];
902 policy = common_entry->policies[0];
903 connected_policy = NULL;
906 flush_cache_policy(common_entry, policy, connected_policy,
907 cache_elemsize_common_continue_func);
910 TRACE_OUT(cache_write);
915 * Initializes the write session for the specified multipart entry. This
916 * session then should be filled with data either committed or abandoned by
917 * using close_cache_mp_write_session or abandon_cache_mp_write_session
919 * Returns NULL on errors (when there are too many opened write sessions for
922 struct cache_mp_write_session_ *
923 open_cache_mp_write_session(struct cache_entry_ *entry)
925 struct cache_mp_entry_ *mp_entry;
926 struct cache_mp_write_session_ *retval;
928 TRACE_IN(open_cache_mp_write_session);
929 assert(entry != NULL);
930 assert(entry->params->entry_type == CET_MULTIPART);
931 mp_entry = (struct cache_mp_entry_ *)entry;
933 if ((mp_entry->mp_params.max_sessions > 0) &&
934 (mp_entry->ws_size == mp_entry->mp_params.max_sessions)) {
935 TRACE_OUT(open_cache_mp_write_session);
941 assert(retval != NULL);
943 TAILQ_INIT(&retval->items);
944 retval->parent_entry = mp_entry;
946 TAILQ_INSERT_HEAD(&mp_entry->ws_head, retval, entries);
949 TRACE_OUT(open_cache_mp_write_session);
954 * Writes data to the specified session. Return 0 on success and -1 on errors
955 * (when write session size limit is exceeded).
958 cache_mp_write(struct cache_mp_write_session_ *ws, char *data,
961 struct cache_mp_data_item_ *new_item;
963 TRACE_IN(cache_mp_write);
965 assert(ws->parent_entry != NULL);
966 assert(ws->parent_entry->params->entry_type == CET_MULTIPART);
968 if ((ws->parent_entry->mp_params.max_elemsize > 0) &&
969 (ws->parent_entry->mp_params.max_elemsize == ws->items_size)) {
970 TRACE_OUT(cache_mp_write);
976 assert(new_item != NULL);
978 new_item->value = malloc(data_size);
979 assert(new_item->value != NULL);
980 memcpy(new_item->value, data, data_size);
981 new_item->value_size = data_size;
983 TAILQ_INSERT_TAIL(&ws->items, new_item, entries);
986 TRACE_OUT(cache_mp_write);
991 * Abandons the write session and frees all the connected resources.
994 abandon_cache_mp_write_session(struct cache_mp_write_session_ *ws)
997 TRACE_IN(abandon_cache_mp_write_session);
999 assert(ws->parent_entry != NULL);
1000 assert(ws->parent_entry->params->entry_type == CET_MULTIPART);
1002 TAILQ_REMOVE(&ws->parent_entry->ws_head, ws, entries);
1003 --ws->parent_entry->ws_size;
1005 destroy_cache_mp_write_session(ws);
1006 TRACE_OUT(abandon_cache_mp_write_session);
1010 * Commits the session to the entry, for which it was created.
1013 close_cache_mp_write_session(struct cache_mp_write_session_ *ws)
1016 TRACE_IN(close_cache_mp_write_session);
1018 assert(ws->parent_entry != NULL);
1019 assert(ws->parent_entry->params->entry_type == CET_MULTIPART);
1021 TAILQ_REMOVE(&ws->parent_entry->ws_head, ws, entries);
1022 --ws->parent_entry->ws_size;
1024 if (ws->parent_entry->completed_write_session == NULL) {
1026 * If there is no completed session yet, this will be the one
1028 ws->parent_entry->get_time_func(
1029 &ws->parent_entry->creation_time);
1030 ws->parent_entry->completed_write_session = ws;
1033 * If there is a completed session, then we'll save our session
1034 * as a pending session. If there is already a pending session,
1035 * it would be destroyed.
1037 if (ws->parent_entry->pending_write_session != NULL)
1038 destroy_cache_mp_write_session(
1039 ws->parent_entry->pending_write_session);
1041 ws->parent_entry->pending_write_session = ws;
1043 TRACE_OUT(close_cache_mp_write_session);
1047 * Opens read session for the specified entry. Returns NULL on errors (when
1048 * there are no data in the entry, or the data are obsolete).
1050 struct cache_mp_read_session_ *
1051 open_cache_mp_read_session(struct cache_entry_ *entry)
1053 struct cache_mp_entry_ *mp_entry;
1054 struct cache_mp_read_session_ *retval;
1056 TRACE_IN(open_cache_mp_read_session);
1057 assert(entry != NULL);
1058 assert(entry->params->entry_type == CET_MULTIPART);
1059 mp_entry = (struct cache_mp_entry_ *)entry;
1061 if (mp_entry->completed_write_session == NULL) {
1062 TRACE_OUT(open_cache_mp_read_session);
1066 if ((mp_entry->mp_params.max_lifetime.tv_sec != 0)
1067 || (mp_entry->mp_params.max_lifetime.tv_usec != 0)) {
1068 if (mp_entry->last_request_time.tv_sec -
1069 mp_entry->last_request_time.tv_sec >
1070 mp_entry->mp_params.max_lifetime.tv_sec) {
1071 flush_cache_entry(entry);
1072 TRACE_OUT(open_cache_mp_read_session);
1079 assert(retval != NULL);
1081 retval->parent_entry = mp_entry;
1082 retval->current_item = TAILQ_FIRST(
1083 &mp_entry->completed_write_session->items);
1085 TAILQ_INSERT_HEAD(&mp_entry->rs_head, retval, entries);
1086 ++mp_entry->rs_size;
1088 mp_entry->get_time_func(&mp_entry->last_request_time);
1089 TRACE_OUT(open_cache_mp_read_session);
1094 * Reads the data from the read session - step by step.
1095 * Returns 0 on success, -1 on error (when there are no more data), and -2 if
1096 * the data_size is too small. In the last case, data_size would be filled
1100 cache_mp_read(struct cache_mp_read_session_ *rs, char *data, size_t *data_size)
1103 TRACE_IN(cache_mp_read);
1106 if (rs->current_item == NULL) {
1107 TRACE_OUT(cache_mp_read);
1111 if (rs->current_item->value_size > *data_size) {
1112 *data_size = rs->current_item->value_size;
1114 TRACE_OUT(cache_mp_read);
1118 TRACE_OUT(cache_mp_read);
1122 *data_size = rs->current_item->value_size;
1123 memcpy(data, rs->current_item->value, rs->current_item->value_size);
1124 rs->current_item = TAILQ_NEXT(rs->current_item, entries);
1126 TRACE_OUT(cache_mp_read);
1131 * Closes the read session. If there are no more read sessions and there is
1132 * a pending write session, it will be committed and old
1133 * completed_write_session will be destroyed.
1136 close_cache_mp_read_session(struct cache_mp_read_session_ *rs)
1139 TRACE_IN(close_cache_mp_read_session);
1141 assert(rs->parent_entry != NULL);
1143 TAILQ_REMOVE(&rs->parent_entry->rs_head, rs, entries);
1144 --rs->parent_entry->rs_size;
1146 if ((rs->parent_entry->rs_size == 0) &&
1147 (rs->parent_entry->pending_write_session != NULL)) {
1148 destroy_cache_mp_write_session(
1149 rs->parent_entry->completed_write_session);
1150 rs->parent_entry->completed_write_session =
1151 rs->parent_entry->pending_write_session;
1152 rs->parent_entry->pending_write_session = NULL;
1155 destroy_cache_mp_read_session(rs);
1156 TRACE_OUT(close_cache_mp_read_session);
1160 transform_cache_entry(struct cache_entry_ *entry,
1161 enum cache_transformation_t transformation)
1164 TRACE_IN(transform_cache_entry);
1165 switch (transformation) {
1167 clear_cache_entry(entry);
1168 TRACE_OUT(transform_cache_entry);
1171 flush_cache_entry(entry);
1172 TRACE_OUT(transform_cache_entry);
1175 TRACE_OUT(transform_cache_entry);
1181 transform_cache_entry_part(struct cache_entry_ *entry,
1182 enum cache_transformation_t transformation, const char *key_part,
1183 size_t key_part_size, enum part_position_t part_position)
1185 struct cache_common_entry_ *common_entry;
1186 struct cache_ht_item_ *ht_item;
1187 struct cache_ht_item_data_ *ht_item_data, ht_key;
1189 struct cache_policy_item_ *item, *connected_item;
1191 TRACE_IN(transform_cache_entry_part);
1192 if (entry->params->entry_type != CET_COMMON) {
1193 TRACE_OUT(transform_cache_entry_part);
1197 if (transformation != CTT_CLEAR) {
1198 TRACE_OUT(transform_cache_entry_part);
1202 memset(&ht_key, 0, sizeof(struct cache_ht_item_data_));
1203 ht_key.key = (char *)key_part; /* can't avoid casting here */
1204 ht_key.key_size = key_part_size;
1206 common_entry = (struct cache_common_entry_ *)entry;
1207 HASHTABLE_FOREACH(&(common_entry->items), ht_item) {
1209 ht_item_data = HASHTABLE_ENTRY_FIND_SPECIAL(cache_ht_,
1211 ht_items_fixed_size_left_cmp_func);
1213 if (ht_item_data != NULL) {
1214 item = ht_item_data->fifo_policy_item;
1215 connected_item = item->connected_item;
1217 common_entry->policies[0]->remove_item_func(
1218 common_entry->policies[0],
1221 free(ht_item_data->key);
1222 free(ht_item_data->value);
1223 HASHTABLE_ENTRY_REMOVE(cache_ht_, ht_item,
1225 --common_entry->items_size;
1227 common_entry->policies[0]->destroy_item_func(
1229 if (common_entry->policies_size == 2) {
1230 common_entry->policies[1]->remove_item_func(
1231 common_entry->policies[1],
1233 common_entry->policies[1]->destroy_item_func(
1237 } while (ht_item_data != NULL);
1240 TRACE_OUT(transform_cache_entry_part);