5 Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
7 Copyright (C) 2000 Pekka Riikonen
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
22 #include "silcincludes.h"
25 /* Static prototypes */
26 static int silc_idcache_sorter(const void *a, const void *b);
27 static SilcIDCacheList silc_idcache_list_alloc();
28 static void silc_idcache_list_add(SilcIDCacheList list,
29 SilcIDCacheEntry cache);
34 This is context for the ID cache system. This includes all the cache
35 entries and other internal data. This is read-only object and not
36 visible outside this cache system.
38 Fields are as follows:
40 SilcIDCacheEntry cache
42 Table of the cache entries allocated by silc_idcache_add function.
43 This table is reallocated when new entry is added into the cache.
45 unsigned int cache_count
47 Number of cache entries in the cache.
51 Boolean value to indicate whether the cache is sorted or not. If
52 cache is not sorted the fast access (described next) cannot be used.
53 Sorting can be done by calling sorting function or when adding new
58 Table to provide fast access into the cache by index. When searching
59 by data this table is used to get the index to the first occurence
60 of that data (or part of the data) in the cache. Purpose of this
61 is to provide faster access to the cache when searching by data.
62 This is updated by silc_idcache_add and sorting functions.
64 SilcIDCacheDestructor destructor
66 Destructor callback that is called when an cache entry expires or is
67 purged from the ID cache. The application must not free cache entry
68 because the library will do it automatically. The appliation, however,
69 is responsible of freeing any data in the entry.
72 struct SilcIDCacheStruct {
73 SilcIDCacheEntry cache;
74 unsigned int cache_count;
77 SilcIDCacheDestructor destructor;
83 This is returned when searching the cache. Enumeration functions are
84 provided to traverse the list; actually this is used as table not as
87 By default the found cache entries are saved into the static cache
88 table to provide access without reallocation. However, if the static
89 table is full, rest of the cache entries are dynamically allocated
90 into `cache_dyn' table. Traversing functions automatically handles
94 struct SilcIDCacheListStruct {
95 SilcIDCacheEntry cache[64];
96 SilcIDCacheEntry *cache_dyn;
97 unsigned int cache_dyn_count;
98 unsigned int cache_count;
102 /* Allocates new ID cache object. The initial amount of allocated entries
103 can be sent as argument. If `count' is 0 the system uses default values. */
105 SilcIDCache silc_idcache_alloc(unsigned int count,
106 SilcIDCacheDestructor destructor)
110 SILC_LOG_DEBUG(("Allocating new cache"));
112 cache = silc_calloc(1, sizeof(*cache));
113 cache->cache = silc_calloc(count ? count : 5, sizeof(*cache->cache));
114 cache->cache_count = count ? count : 5;
115 memset(cache->fast_access, -1, sizeof(cache->fast_access));
116 cache->destructor = destructor;
121 /* Free's ID cache object and cache entries */
123 void silc_idcache_free(SilcIDCache cache)
126 silc_free(cache->cache);
131 /* qsort() sorter function. */
133 static int silc_idcache_sorter(const void *a, const void *b)
135 SilcIDCacheEntry a1, b1;
137 a1 = (SilcIDCacheEntry)a;
138 b1 = (SilcIDCacheEntry)b;
140 if (!a1->data && !b1->data)
149 return a1->data[0] - b1->data[0];
152 /* Sorts given cache by data. After sorting this updates the fast access
153 table that can be used to access the cache faster. */
155 void silc_idcache_sort_by_data(SilcIDCache cache)
159 qsort(cache->cache, cache->cache_count,
160 sizeof(*cache->cache), silc_idcache_sorter);
162 memset(cache->fast_access, -1, sizeof(cache->fast_access));
164 /* Update the fast access table (this of course takes its own time when
165 the cache is very large). */
166 for (i = 0; i < cache->cache_count; i++) {
167 if (cache->cache[i].data &&
168 cache->fast_access[(int)cache->cache[i].data[0]] == -1)
169 cache->fast_access[(int)cache->cache[i].data[0]] = i;
172 cache->sorted = TRUE;
175 /* Find ID Cache entry by data. The data maybe anything that must
176 match exactly. Returns list of cache entries. */
178 int silc_idcache_find_by_data(SilcIDCache cache, unsigned char *data,
179 SilcIDCacheList *ret)
182 SilcIDCacheList list;
184 if (!cache || !cache->cache || !data)
187 list = silc_idcache_list_alloc();
190 i = cache->fast_access[(int)data[0]];
197 for (i = i; i < cache->cache_count; i++) {
198 if (cache->sorted && cache->cache[i].data &&
199 cache->cache[i].data[0] != data[0])
202 if (cache->cache[i].data &&
203 !memcmp(cache->cache[i].data, data, strlen(cache->cache[i].data)))
204 silc_idcache_list_add(list, &(cache->cache[i]));
207 if (!silc_idcache_list_count(list))
213 silc_idcache_list_free(list);
218 /* Find ID Cache entry by data. The data maybe anything that must
219 match exactly. Returns one cache entry. */
221 int silc_idcache_find_by_data_one(SilcIDCache cache, unsigned char *data,
222 SilcIDCacheEntry *ret)
226 if (!cache || !cache->cache || !data)
230 i = cache->fast_access[(int)data[0]];
237 for (i = i; i < cache->cache_count; i++)
238 if (cache->cache[i].data &&
239 !memcmp(cache->cache[i].data, data, strlen(cache->cache[i].data))) {
241 *ret = &(cache->cache[i]);
248 /* Find ID Cache entry by data, loosely. The data don't have to be 100%
249 match. This ignores data case-sensitivity when searching with this
250 function. Returns list of cache entries. */
252 int silc_idcache_find_by_data_loose(SilcIDCache cache, unsigned char *data,
253 SilcIDCacheList *ret)
256 SilcIDCacheList list;
258 if (!cache || !cache->cache || !data)
261 list = silc_idcache_list_alloc();
263 c = tolower((int)data[0]);
266 i = cache->fast_access[c];
273 for (i = i; i < cache->cache_count; i++) {
274 if (cache->sorted && cache->cache[i].data &&
275 cache->cache[i].data[0] != (char)c)
278 if (cache->cache[i].data &&
279 !strcasecmp(cache->cache[i].data, data))
280 silc_idcache_list_add(list, &(cache->cache[i]));
284 c = toupper((int)data[0]);
285 i = cache->fast_access[c];
287 for (i = i; i < cache->cache_count; i++) {
288 if (cache->sorted && cache->cache[i].data &&
289 cache->cache[i].data[0] != (char)c)
292 if (cache->cache[i].data &&
293 !strcasecmp(cache->cache[i].data, data))
294 silc_idcache_list_add(list, &(cache->cache[i]));
298 if (!silc_idcache_list_count(list))
304 silc_idcache_list_free(list);
309 /* Find ID Cache entry by ID. Returns list of cache entries. If `id' is
310 SILC_ID_CACHE_ANY this returns all ID's of type `type'. */
312 int silc_idcache_find_by_id(SilcIDCache cache, void *id, SilcIdType type,
313 SilcIDCacheList *ret)
316 SilcIDCacheList list;
318 if (!cache || !cache->cache || !id)
321 id_len = silc_id_get_len(type);
323 list = silc_idcache_list_alloc();
325 if (id != SILC_ID_CACHE_ANY) {
326 for (i = 0; i < cache->cache_count; i++)
327 if (cache->cache[i].id && !memcmp(cache->cache[i].id, id, id_len))
328 silc_idcache_list_add(list, &(cache->cache[i]));
330 for (i = 0; i < cache->cache_count; i++)
331 if (cache->cache[i].id && cache->cache[i].type == type)
332 silc_idcache_list_add(list, &(cache->cache[i]));
335 if (!silc_idcache_list_count(list))
341 silc_idcache_list_free(list);
346 /* Find ID Cache entry by ID. Returns one cache entry. */
348 int silc_idcache_find_by_id_one(SilcIDCache cache, void *id, SilcIdType type,
349 SilcIDCacheEntry *ret)
353 if (!cache || !cache->cache || !id)
356 id_len = silc_id_get_len(type);
358 for (i = 0; i < cache->cache_count; i++)
359 if (cache->cache[i].id && !memcmp(cache->cache[i].id, id, id_len)) {
361 *ret = &(cache->cache[i]);
368 /* Finds cache entry by context. */
370 int silc_idcache_find_by_context(SilcIDCache cache, void *context,
371 SilcIDCacheEntry *ret)
375 if (!cache || !cache->cache || !context)
378 for (i = 0; i < cache->cache_count; i++)
379 if (cache->cache[i].context && cache->cache[i].context == context) {
381 *ret = &(cache->cache[i]);
388 /* Add new entry to the cache. Returns TRUE or FALSE. If `sort' is TRUE
389 then the cache is sorted after the new entry has been added. The
390 cache must be sorted in order for the fast access feature to work,
391 however, it is not mandatory. */
393 int silc_idcache_add(SilcIDCache cache, unsigned char *data,
394 SilcIdType id_type, void *id, void *context, int sort,
399 unsigned long curtime = time(NULL);
402 if (!cache || !cache->cache)
405 SILC_LOG_DEBUG(("Adding cache entry"));
408 count = cache->cache_count;
411 c = silc_calloc(5, sizeof(*c));
415 /* See if it exists already */
416 /* XXX this slows down this function. */
417 if (silc_idcache_find_by_id(cache, id, id_type, NULL))
420 for (i = 0; i < count; i++) {
421 if (c[i].data == NULL && c[i].id == NULL) {
425 c[i].expire = (expire ? (curtime + SILC_ID_CACHE_EXPIRE) : 0);
426 c[i].context = context;
432 c = silc_realloc(c, sizeof(*c) * (count + 5));
433 for (i = count; i < count + 5; i++) {
437 c[count].data = data;
438 c[count].type = id_type;
440 c[count].expire = (expire ? (curtime + SILC_ID_CACHE_EXPIRE) : 0);
441 c[count].context = context;
446 cache->cache_count = count;
447 cache->sorted = sort;
450 silc_idcache_sort_by_data(cache);
455 /* Delete cache entry from cache. */
458 int silc_idcache_del(SilcIDCache cache, SilcIDCacheEntry old)
466 int silc_idcache_del_by_data(SilcIDCache cache, unsigned char *data)
472 /* Deletes ID cache entry by ID. */
474 int silc_idcache_del_by_id(SilcIDCache cache, SilcIdType type, void *id)
478 if (!cache || !cache->cache || !id)
481 id_len = silc_id_get_len(type);
483 for (i = 0; i < cache->cache_count; i++)
484 if (cache->cache[i].id && !memcmp(cache->cache[i].id, id, id_len)) {
485 cache->cache[i].id = NULL;
486 cache->cache[i].data = NULL;
487 cache->cache[i].type = 0;
488 cache->cache[i].context = NULL;
495 /* Deletes all ID entries from cache. Free's memory as well. */
497 int silc_idcache_del_all(SilcIDCache cache)
499 if (!cache || !cache->cache)
502 silc_free(cache->cache);
504 cache->cache_count = 0;
509 /* Purges the cache by removing expired cache entires. This does not
510 free any memory though. */
512 int silc_idcache_purge(SilcIDCache cache)
515 unsigned long curtime = time(NULL);
518 if (!cache || !cache->cache)
523 for (i = 0; i < cache->cache_count; i++) {
524 if (c[i].data && c[i].expire < curtime) {
526 /* Call the destructor */
527 if (cache->destructor)
528 cache->destructor(cache, &c[i]);
541 /* Purges the specific entry by context. */
543 int silc_idcache_purge_by_context(SilcIDCache cache, void *context)
545 SilcIDCacheEntry entry;
547 if (!silc_idcache_find_by_context(cache, context, &entry))
550 /* Call the destructor */
551 if (cache->destructor)
552 cache->destructor(cache, entry);
558 entry->context = NULL;
562 /* Allocates ID cache list. */
564 static SilcIDCacheList silc_idcache_list_alloc()
566 SilcIDCacheList list;
568 list = silc_calloc(1, sizeof(*list));
573 /* Adds cache entry to the ID cache list. If needed reallocates memory
576 static void silc_idcache_list_add(SilcIDCacheList list, SilcIDCacheEntry cache)
580 /* Try to add to static cache */
581 if (!list->cache_dyn_count)
582 for (i = 0; i < sizeof(list->cache); i++) {
583 if (!list->cache[i]) {
584 list->cache[i] = cache;
590 /* Static cache is full, allocate dynamic cache */
591 for (i = 0; i < list->cache_dyn_count; i++) {
592 if (!list->cache_dyn[i]) {
593 list->cache_dyn[i] = cache;
599 if (i >= list->cache_dyn_count) {
603 list->cache_dyn = silc_realloc(list->cache_dyn,
604 sizeof(*list->cache) * (i));
606 /* NULL the reallocated area */
607 for (k = list->cache_dyn_count; k < i; k++)
608 list->cache_dyn[k] = NULL;
610 list->cache_dyn[list->cache_dyn_count] = cache;
611 list->cache_dyn_count = i;
616 /* Returns number of cache entries in the ID cache list. */
618 int silc_idcache_list_count(SilcIDCacheList list)
620 return list->cache_count;
623 /* Returns first entry from the ID cache list. */
625 int silc_idcache_list_first(SilcIDCacheList list, SilcIDCacheEntry *ret)
629 if (!list->cache[list->pos])
633 *ret = list->cache[list->pos];
638 /* Returns next entry from the ID cache list. */
640 int silc_idcache_list_next(SilcIDCacheList list, SilcIDCacheEntry *ret)
645 if (list->pos >= sizeof(list->cache)) {
650 if (dyn && list->pos >= list->cache_dyn_count)
653 if (!dyn && !list->cache[list->pos])
656 if (dyn && !list->cache_dyn[list->pos])
661 *ret = list->cache[list->pos];
663 *ret = list->cache_dyn[list->pos];
669 /* Free's ID cache list. User must free the list object returned by
670 any of the searching functions. */
672 void silc_idcache_list_free(SilcIDCacheList list)
676 silc_free(list->cache_dyn);