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 /* Free's 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. */
139 bool silc_idcache_add(SilcIDCache cache, char *name, void *id,
140 void *context, int expire)
143 uint32 curtime = time(NULL);
145 SILC_LOG_DEBUG(("Adding cache entry"));
147 /* Allocate new cache entry */
148 c = silc_calloc(1, sizeof(*c));
151 c->expire = (expire ? (curtime + SILC_ID_CACHE_EXPIRE) : 0);
152 c->context = context;
154 /* Add the new entry to the hash tables */
157 silc_hash_table_add(cache->id_table, id, c);
159 silc_hash_table_add(cache->name_table, name, c);
161 silc_hash_table_add(cache->context_table, context, c);
163 /* See whether we have time to rehash the tables */
164 if ((silc_hash_table_count(cache->id_table) / 2) >
165 silc_hash_table_size(cache->id_table)) {
166 silc_hash_table_rehash(cache->id_table, 0);
167 silc_hash_table_rehash(cache->name_table, 0);
168 silc_hash_table_rehash(cache->context_table, 0);
174 /* Destructor for the ID Cache entry */
176 static void silc_idcache_destructor(void *key, void *context,
182 /* Delete cache entry from cache. */
184 bool silc_idcache_del(SilcIDCache cache, SilcIDCacheEntry old)
188 SILC_LOG_DEBUG(("Deleting cache entry"));
191 ret = silc_hash_table_del_by_context(cache->name_table, old->name, old);
193 ret = silc_hash_table_del(cache->context_table, old->context);
195 ret = silc_hash_table_del(cache->id_table, old->id);
200 /* Deletes ID cache entry by ID. */
202 bool silc_idcache_del_by_id(SilcIDCache cache, void *id)
206 if (!silc_hash_table_find(cache->id_table, id, NULL, (void *)&c))
209 return silc_idcache_del(cache, c);
212 /* Same as above but with specific hash and comparison functions. If the
213 functions are NULL then default values are used. */
215 bool silc_idcache_del_by_id_ext(SilcIDCache cache, void *id,
216 SilcHashFunction hash,
218 SilcHashCompare compare,
219 void *compare_context)
224 SILC_LOG_DEBUG(("Deleting cache entry"));
226 if (!silc_hash_table_find_ext(cache->id_table, id, NULL, (void *)&c,
227 hash, hash_context, compare,
232 ret = silc_hash_table_del_by_context(cache->name_table, c->name, c);
234 ret = silc_hash_table_del(cache->context_table, c->context);
236 ret = silc_hash_table_del_ext(cache->id_table, c->id, hash,
237 hash_context, compare, compare_context);
242 /* Deletes ID cache entry by context. */
244 bool silc_idcache_del_by_context(SilcIDCache cache, void *context)
249 SILC_LOG_DEBUG(("Deleting cache entry"));
251 if (!silc_hash_table_find(cache->context_table, context, NULL, (void *)&c))
255 ret = silc_hash_table_del_by_context(cache->name_table, c->name, c);
257 ret = silc_hash_table_del(cache->context_table, c->context);
259 ret = silc_hash_table_del_by_context(cache->id_table, c->id, c);
264 /* Deletes all ID entries from cache. Free's memory as well. */
266 bool silc_idcache_del_all(SilcIDCache cache)
268 silc_hash_table_free(cache->id_table);
269 silc_hash_table_free(cache->name_table);
270 silc_hash_table_free(cache->context_table);
275 /* Foreach callback fro silc_idcache_purge. */
277 static void silc_idcache_purge_foreach(void *key, void *context,
280 SilcIDCache cache = (SilcIDCache)user_context;
281 uint32 curtime = time(NULL);
282 SilcIDCacheEntry c = (SilcIDCacheEntry)context;
284 if (c->expire && c->expire < curtime) {
285 /* Call the destructor */
286 if (cache->destructor)
287 cache->destructor(cache, c);
289 /* Delete the entry */
290 silc_idcache_del(cache, c);
294 /* Purges the cache by removing expired cache entires. Note that this
295 may be very slow operation. */
297 bool silc_idcache_purge(SilcIDCache cache)
299 silc_hash_table_foreach(cache->id_table, silc_idcache_purge_foreach, cache);
303 /* Purges the specific entry by context. */
305 bool silc_idcache_purge_by_context(SilcIDCache cache, void *context)
307 SilcIDCacheEntry entry;
310 if (!silc_hash_table_find(cache->context_table, context, NULL,
314 /* Call the destructor */
315 if (cache->destructor)
316 cache->destructor(cache, entry);
319 ret = silc_hash_table_del_by_context(cache->name_table, entry->name,
322 ret = silc_hash_table_del(cache->context_table, entry->context);
324 ret = silc_hash_table_del_by_context(cache->id_table, entry->id, entry);
329 /* Callback that is called by the hash table routine when traversing
330 entrys in the hash table. */
332 static void silc_idcache_get_all_foreach(void *key, void *context,
335 SilcIDCacheList list = (SilcIDCacheList)user_context;
336 silc_idcache_list_add(list, (SilcIDCacheEntry)context);
339 /* Returns all cache entrys from the ID cache to the `ret' ID Cache List. */
341 bool silc_idcache_get_all(SilcIDCache cache, SilcIDCacheList *ret)
343 SilcIDCacheList list;
348 list = silc_idcache_list_alloc();
349 silc_hash_table_foreach(cache->id_table, silc_idcache_get_all_foreach, list);
351 if (silc_idcache_list_count(list) == 0) {
352 silc_idcache_list_free(list);
361 /* Find ID Cache entry by ID. May return multiple entries. */
363 bool silc_idcache_find_by_id(SilcIDCache cache, void *id,
364 SilcIDCacheList *ret)
366 SilcIDCacheList list;
368 list = silc_idcache_list_alloc();
373 silc_hash_table_find_foreach(cache->id_table, id,
374 silc_idcache_get_all_foreach, list);
376 if (silc_idcache_list_count(list) == 0) {
377 silc_idcache_list_free(list);
386 /* Find specific ID with specific hash function and comparison functions.
387 If `hash' is NULL then the default hash funtion is used and if `compare'
388 is NULL default comparison function is used. */
390 bool silc_idcache_find_by_id_one_ext(SilcIDCache cache, void *id,
391 SilcHashFunction hash,
393 SilcHashCompare compare,
394 void *compare_context,
395 SilcIDCacheEntry *ret)
397 return silc_hash_table_find_ext(cache->id_table, id, NULL, (void *)ret,
398 hash, hash_context, compare,
402 /* Find one specific ID entry. */
404 bool silc_idcache_find_by_id_one(SilcIDCache cache, void *id,
405 SilcIDCacheEntry *ret)
407 return silc_hash_table_find(cache->id_table, id, NULL, (void *)ret);
410 /* Finds cache entry by context. */
412 bool silc_idcache_find_by_context(SilcIDCache cache, void *context,
413 SilcIDCacheEntry *ret)
415 return silc_hash_table_find(cache->context_table, context, NULL,
419 /* Find ID Cache entry by name. Returns list of cache entries. */
421 bool silc_idcache_find_by_name(SilcIDCache cache, char *name,
422 SilcIDCacheList *ret)
424 SilcIDCacheList list;
426 list = silc_idcache_list_alloc();
431 silc_hash_table_find_foreach(cache->name_table, name,
432 silc_idcache_get_all_foreach, list);
434 if (silc_idcache_list_count(list) == 0) {
435 silc_idcache_list_free(list);
444 /* Find ID Cache entry by name. Returns one cache entry. */
446 bool silc_idcache_find_by_name_one(SilcIDCache cache, char *name,
447 SilcIDCacheEntry *ret)
449 if (!silc_hash_table_find(cache->name_table, name, NULL, (void *)ret))
455 /* Allocates ID cache list. */
457 static SilcIDCacheList silc_idcache_list_alloc()
459 SilcIDCacheList list;
461 list = silc_calloc(1, sizeof(*list));
466 /* Adds cache entry to the ID cache list. If needed reallocates memory
469 static void silc_idcache_list_add(SilcIDCacheList list, SilcIDCacheEntry cache)
473 /* Try to add to static cache */
474 if (!list->cache_dyn_count)
475 for (i = 0; i < sizeof(list->cache); i++) {
476 if (!list->cache[i]) {
477 list->cache[i] = cache;
483 /* Static cache is full, allocate dynamic cache */
484 for (i = 0; i < list->cache_dyn_count; i++) {
485 if (!list->cache_dyn[i]) {
486 list->cache_dyn[i] = cache;
492 if (i >= list->cache_dyn_count) {
496 list->cache_dyn = silc_realloc(list->cache_dyn,
497 sizeof(*list->cache) * (i));
499 /* NULL the reallocated area */
500 for (k = list->cache_dyn_count; k < i; k++)
501 list->cache_dyn[k] = NULL;
503 list->cache_dyn[list->cache_dyn_count] = cache;
504 list->cache_dyn_count = i;
509 /* Returns number of cache entries in the ID cache list. */
511 int silc_idcache_list_count(SilcIDCacheList list)
513 return list->cache_count;
516 /* Returns first entry from the ID cache list. */
518 bool silc_idcache_list_first(SilcIDCacheList list, SilcIDCacheEntry *ret)
522 if (!list->cache[list->pos])
526 *ret = list->cache[list->pos];
531 /* Returns next entry from the ID cache list. */
533 bool silc_idcache_list_next(SilcIDCacheList list, SilcIDCacheEntry *ret)
538 if (list->pos >= sizeof(list->cache)) {
543 if (dyn && list->pos >= list->cache_dyn_count)
546 if (!dyn && !list->cache[list->pos])
549 if (dyn && !list->cache_dyn[list->pos])
554 *ret = list->cache[list->pos];
556 *ret = list->cache_dyn[list->pos];
562 /* Free's ID cache list. User must free the list object returned by
563 any of the searching functions. */
565 void silc_idcache_list_free(SilcIDCacheList list)
569 silc_free(list->cache_dyn);