5 Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
7 Copyright (C) 2000 - 2001 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"
23 #include "silcidcache.h"
25 /* Static prototypes */
26 static void silc_idcache_destructor(void *key, void *context,
28 static SilcIDCacheList silc_idcache_list_alloc();
29 static void silc_idcache_list_add(SilcIDCacheList list,
30 SilcIDCacheEntry cache);
35 This is context for the ID cache system. This includes all the cache
36 entries and other internal data. This is read-only object and not
37 visible outside this cache system.
39 Fields are as follows:
41 SilcHashTable id_table
43 Hash table using the ID as the key.
45 SilcHashTable name_table
47 Hash table using the name as the key.
49 SilcHashTable context_table
51 Hash table using the context as the key.
53 SilcIDCacheDestructor destructor
55 Destructor callback that is called when an cache entry expires or is
56 purged from the ID cache. The application must not free cache entry
57 because the library will do it automatically. The appliation, however,
58 is responsible of freeing any data in the entry.
62 Indicates the type of the ID's this cache holds.
65 struct SilcIDCacheStruct {
66 SilcHashTable id_table;
67 SilcHashTable name_table;
68 SilcHashTable context_table;
69 SilcIDCacheDestructor destructor;
76 This is returned when searching the cache. Enumeration functions are
77 provided to traverse the list; actually this is used as table not as
80 By default the found cache entries are saved into the static cache
81 table to provide access without reallocation. However, if the static
82 table is full, rest of the cache entries are dynamically allocated
83 into `cache_dyn' table. Traversing functions automatically handles
87 struct SilcIDCacheListStruct {
88 SilcIDCacheEntry cache[64];
89 SilcIDCacheEntry *cache_dyn;
90 uint32 cache_dyn_count;
95 /* Allocates new ID cache object. The initial amount of allocated entries
96 can be sent as argument. If `count' is 0 the system uses default values.
97 The `id_type' defines the types of the ID's that will be saved to the
100 SilcIDCache silc_idcache_alloc(uint32 count, SilcIdType id_type,
101 SilcIDCacheDestructor destructor)
105 SILC_LOG_DEBUG(("Allocating new cache"));
107 cache = silc_calloc(1, sizeof(*cache));
108 cache->id_table = silc_hash_table_alloc(count, silc_hash_id,
109 (void *)(uint32)id_type,
110 silc_hash_id_compare,
111 (void *)(uint32)id_type,
112 silc_idcache_destructor, NULL,
114 cache->name_table = silc_hash_table_alloc(count, silc_hash_string, NULL,
115 silc_hash_string_compare, NULL,
117 cache->context_table = silc_hash_table_alloc(count, silc_hash_ptr, NULL,
118 NULL, NULL, NULL, NULL, FALSE);
119 cache->destructor = destructor;
120 cache->type = id_type;
125 /* Frees ID cache object and cache entries */
127 void silc_idcache_free(SilcIDCache cache)
130 silc_hash_table_free(cache->id_table);
131 silc_hash_table_free(cache->name_table);
132 silc_hash_table_free(cache->context_table);
137 /* Add new entry to the cache. Returns TRUE if the entry was added and
138 FALSE if it could not be added. The `name' is the name associated with
139 the ID, the `id' the actual ID and the `context' a used specific context.
140 If the `expire' is TRUE the entry expires in default time and if FALSE
141 the entry never expires from the cache. */
143 bool silc_idcache_add(SilcIDCache cache, char *name, void *id,
144 void *context, int expire)
147 uint32 curtime = time(NULL);
149 SILC_LOG_DEBUG(("Adding cache entry"));
151 /* Allocate new cache entry */
152 c = silc_calloc(1, sizeof(*c));
155 c->expire = (expire ? (curtime + SILC_ID_CACHE_EXPIRE) : 0);
156 c->context = context;
158 /* Add the new entry to the hash tables */
161 silc_hash_table_add(cache->id_table, id, c);
163 silc_hash_table_add(cache->name_table, name, c);
165 silc_hash_table_add(cache->context_table, context, c);
167 /* See whether we have time to rehash the tables */
168 if ((silc_hash_table_count(cache->id_table) / 2) >
169 silc_hash_table_size(cache->id_table)) {
170 silc_hash_table_rehash(cache->id_table, 0);
171 silc_hash_table_rehash(cache->name_table, 0);
172 silc_hash_table_rehash(cache->context_table, 0);
178 /* Destructor for the ID Cache entry */
180 static void silc_idcache_destructor(void *key, void *context,
186 /* Delete cache entry from cache. */
188 bool silc_idcache_del(SilcIDCache cache, SilcIDCacheEntry old)
192 SILC_LOG_DEBUG(("Deleting cache entry"));
195 ret = silc_hash_table_del_by_context(cache->name_table, old->name, old);
197 ret = silc_hash_table_del(cache->context_table, old->context);
199 ret = silc_hash_table_del(cache->id_table, old->id);
204 /* Deletes ID cache entry by ID. */
206 bool silc_idcache_del_by_id(SilcIDCache cache, void *id)
210 if (!silc_hash_table_find(cache->id_table, id, NULL, (void *)&c))
213 return silc_idcache_del(cache, c);
216 /* Same as above but with specific hash and comparison functions. If the
217 functions are NULL then default values are used. */
219 bool silc_idcache_del_by_id_ext(SilcIDCache cache, void *id,
220 SilcHashFunction hash,
222 SilcHashCompare compare,
223 void *compare_context)
228 SILC_LOG_DEBUG(("Deleting cache entry"));
230 if (!silc_hash_table_find_ext(cache->id_table, id, NULL, (void *)&c,
231 hash, hash_context, compare,
236 ret = silc_hash_table_del_by_context(cache->name_table, c->name, c);
238 ret = silc_hash_table_del(cache->context_table, c->context);
240 ret = silc_hash_table_del_ext(cache->id_table, c->id, hash,
241 hash_context, compare, compare_context);
246 /* Deletes ID cache entry by context. */
248 bool silc_idcache_del_by_context(SilcIDCache cache, void *context)
253 SILC_LOG_DEBUG(("Deleting cache entry"));
255 if (!silc_hash_table_find(cache->context_table, context, NULL, (void *)&c))
259 ret = silc_hash_table_del_by_context(cache->name_table, c->name, c);
261 ret = silc_hash_table_del(cache->context_table, c->context);
263 ret = silc_hash_table_del_by_context(cache->id_table, c->id, c);
268 /* Deletes all ID entries from cache. Free's memory as well. */
270 bool silc_idcache_del_all(SilcIDCache cache)
272 silc_hash_table_free(cache->id_table);
273 silc_hash_table_free(cache->name_table);
274 silc_hash_table_free(cache->context_table);
279 /* Foreach callback fro silc_idcache_purge. */
281 static void silc_idcache_purge_foreach(void *key, void *context,
284 SilcIDCache cache = (SilcIDCache)user_context;
285 uint32 curtime = time(NULL);
286 SilcIDCacheEntry c = (SilcIDCacheEntry)context;
288 if (c->expire && c->expire < curtime) {
289 /* Call the destructor */
290 if (cache->destructor)
291 cache->destructor(cache, c);
293 /* Delete the entry */
294 silc_idcache_del(cache, c);
298 /* Purges the cache by removing expired cache entires. Note that this
299 may be very slow operation. */
301 bool silc_idcache_purge(SilcIDCache cache)
303 silc_hash_table_foreach(cache->id_table, silc_idcache_purge_foreach, cache);
307 /* Purges the specific entry by context. */
309 bool silc_idcache_purge_by_context(SilcIDCache cache, void *context)
311 SilcIDCacheEntry entry;
314 if (!silc_hash_table_find(cache->context_table, context, NULL,
318 /* Call the destructor */
319 if (cache->destructor)
320 cache->destructor(cache, entry);
323 ret = silc_hash_table_del_by_context(cache->name_table, entry->name,
326 ret = silc_hash_table_del(cache->context_table, entry->context);
328 ret = silc_hash_table_del_by_context(cache->id_table, entry->id, entry);
333 /* Callback that is called by the hash table routine when traversing
334 entrys in the hash table. */
336 static void silc_idcache_get_all_foreach(void *key, void *context,
339 SilcIDCacheList list = (SilcIDCacheList)user_context;
340 silc_idcache_list_add(list, (SilcIDCacheEntry)context);
343 /* Returns all cache entrys from the ID cache to the `ret' ID Cache List. */
345 bool silc_idcache_get_all(SilcIDCache cache, SilcIDCacheList *ret)
347 SilcIDCacheList list;
352 list = silc_idcache_list_alloc();
353 silc_hash_table_foreach(cache->id_table, silc_idcache_get_all_foreach, list);
355 if (silc_idcache_list_count(list) == 0) {
356 silc_idcache_list_free(list);
365 /* Find ID Cache entry by ID. May return multiple entries. */
367 bool silc_idcache_find_by_id(SilcIDCache cache, void *id,
368 SilcIDCacheList *ret)
370 SilcIDCacheList list;
372 list = silc_idcache_list_alloc();
377 silc_hash_table_find_foreach(cache->id_table, id,
378 silc_idcache_get_all_foreach, list);
380 if (silc_idcache_list_count(list) == 0) {
381 silc_idcache_list_free(list);
390 /* Find specific ID with specific hash function and comparison functions.
391 If `hash' is NULL then the default hash funtion is used and if `compare'
392 is NULL default comparison function is used. */
394 bool silc_idcache_find_by_id_one_ext(SilcIDCache cache, void *id,
395 SilcHashFunction hash,
397 SilcHashCompare compare,
398 void *compare_context,
399 SilcIDCacheEntry *ret)
401 return silc_hash_table_find_ext(cache->id_table, id, NULL, (void *)ret,
402 hash, hash_context, compare,
406 /* Find one specific ID entry. */
408 bool silc_idcache_find_by_id_one(SilcIDCache cache, void *id,
409 SilcIDCacheEntry *ret)
411 return silc_hash_table_find(cache->id_table, id, NULL, (void *)ret);
414 /* Finds cache entry by context. */
416 bool silc_idcache_find_by_context(SilcIDCache cache, void *context,
417 SilcIDCacheEntry *ret)
419 return silc_hash_table_find(cache->context_table, context, NULL,
423 /* Find ID Cache entry by name. Returns list of cache entries. */
425 bool silc_idcache_find_by_name(SilcIDCache cache, char *name,
426 SilcIDCacheList *ret)
428 SilcIDCacheList list;
430 list = silc_idcache_list_alloc();
435 silc_hash_table_find_foreach(cache->name_table, name,
436 silc_idcache_get_all_foreach, list);
438 if (silc_idcache_list_count(list) == 0) {
439 silc_idcache_list_free(list);
448 /* Find ID Cache entry by name. Returns one cache entry. */
450 bool silc_idcache_find_by_name_one(SilcIDCache cache, char *name,
451 SilcIDCacheEntry *ret)
453 if (!silc_hash_table_find(cache->name_table, name, NULL, (void *)ret))
459 /* Allocates ID cache list. */
461 static SilcIDCacheList silc_idcache_list_alloc()
463 SilcIDCacheList list;
465 list = silc_calloc(1, sizeof(*list));
470 /* Adds cache entry to the ID cache list. If needed reallocates memory
473 static void silc_idcache_list_add(SilcIDCacheList list, SilcIDCacheEntry cache)
477 /* Try to add to static cache */
478 if (!list->cache_dyn_count)
479 for (i = 0; i < sizeof(list->cache); i++) {
480 if (!list->cache[i]) {
481 list->cache[i] = cache;
487 /* Static cache is full, allocate dynamic cache */
488 for (i = 0; i < list->cache_dyn_count; i++) {
489 if (!list->cache_dyn[i]) {
490 list->cache_dyn[i] = cache;
496 if (i >= list->cache_dyn_count) {
500 list->cache_dyn = silc_realloc(list->cache_dyn,
501 sizeof(*list->cache) * (i));
503 /* NULL the reallocated area */
504 for (k = list->cache_dyn_count; k < i; k++)
505 list->cache_dyn[k] = NULL;
507 list->cache_dyn[list->cache_dyn_count] = cache;
508 list->cache_dyn_count = i;
513 /* Returns number of cache entries in the ID cache list. */
515 int silc_idcache_list_count(SilcIDCacheList list)
517 return list->cache_count;
520 /* Returns first entry from the ID cache list. */
522 bool silc_idcache_list_first(SilcIDCacheList list, SilcIDCacheEntry *ret)
526 if (!list->cache[list->pos])
530 *ret = list->cache[list->pos];
535 /* Returns next entry from the ID cache list. */
537 bool silc_idcache_list_next(SilcIDCacheList list, SilcIDCacheEntry *ret)
542 if (list->pos >= sizeof(list->cache)) {
547 if (dyn && list->pos >= list->cache_dyn_count)
550 if (!dyn && !list->cache[list->pos])
553 if (dyn && !list->cache_dyn[list->pos])
558 *ret = list->cache[list->pos];
560 *ret = list->cache_dyn[list->pos];
566 /* Frees ID cache list. User must free the list object returned by
567 any of the searching functions. */
569 void silc_idcache_list_free(SilcIDCacheList list)
573 silc_free(list->cache_dyn);