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"
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 data_table
47 Hash table using the data 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 data_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);
113 cache->data_table = silc_hash_table_alloc(count, silc_hash_data, NULL,
114 silc_hash_data_compare, NULL,
116 cache->context_table = silc_hash_table_alloc(count, silc_hash_ptr, NULL,
117 NULL, NULL, NULL, NULL);
118 cache->destructor = destructor;
119 cache->type = id_type;
124 /* Free's ID cache object and cache entries */
126 void silc_idcache_free(SilcIDCache cache)
129 silc_hash_table_free(cache->id_table);
130 silc_hash_table_free(cache->data_table);
131 silc_hash_table_free(cache->context_table);
136 /* Add new entry to the cache. */
138 bool silc_idcache_add(SilcIDCache cache, unsigned char *data,
139 uint32 data_len, void *id, void *context, int expire)
142 uint32 curtime = time(NULL);
144 SILC_LOG_DEBUG(("Adding cache entry"));
146 /* See if entry with this ID already exists. */
147 if (silc_hash_table_find(cache->id_table, id, NULL, NULL))
150 /* Allocate new cache entry */
151 c = silc_calloc(1, sizeof(*c));
153 c->data_len = data_len;
155 c->expire = (expire ? (curtime + SILC_ID_CACHE_EXPIRE) : 0);
156 c->context = context;
158 /* Add the new entry to the hash tables */
160 silc_hash_table_add(cache->id_table, id, c);
162 silc_hash_table_add_ext(cache->data_table, data, c,
163 silc_hash_data, (void *)data_len);
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->data_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 ret = silc_hash_table_del_by_context(cache->data_table, old->data,
194 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)
207 if (!silc_hash_table_find(cache->id_table, id, NULL, (void *)&c))
210 ret = silc_hash_table_del_by_context(cache->data_table, c->data,
212 ret = silc_hash_table_del(cache->context_table, c->context);
213 ret = silc_hash_table_del(cache->id_table, c->id);
218 /* Deletes all ID entries from cache. Free's memory as well. */
220 bool silc_idcache_del_all(SilcIDCache cache)
222 silc_hash_table_free(cache->id_table);
223 silc_hash_table_free(cache->data_table);
224 silc_hash_table_free(cache->context_table);
228 /* Foreach callback fro silc_idcache_purge. */
230 static void silc_idcache_purge_foreach(void *key, void *context,
233 SilcIDCache cache = (SilcIDCache)user_context;
234 uint32 curtime = time(NULL);
235 SilcIDCacheEntry c = (SilcIDCacheEntry)context;
237 if (c->expire && c->expire < curtime) {
238 /* Call the destructor */
239 if (cache->destructor)
240 cache->destructor(cache, c);
242 /* Delete the entry */
243 silc_idcache_del(cache, c);
247 /* Purges the cache by removing expired cache entires. Note that this
248 may be very slow operation. */
250 bool silc_idcache_purge(SilcIDCache cache)
252 silc_hash_table_foreach(cache->id_table, silc_idcache_purge_foreach, cache);
256 /* Purges the specific entry by context. */
258 bool silc_idcache_purge_by_context(SilcIDCache cache, void *context)
260 SilcIDCacheEntry entry;
262 if (!silc_hash_table_find(cache->context_table, context, NULL,
266 /* Call the destructor */
267 if (cache->destructor)
268 cache->destructor(cache, entry);
270 return silc_idcache_del(cache, entry);
273 /* Callback that is called by the hash table routine when traversing
274 all entrys in the hash table. */
276 static void silc_idcache_get_all_foreach(void *key, void *context,
279 SilcIDCacheList list = (SilcIDCacheList)user_context;
280 silc_idcache_list_add(list, (SilcIDCacheEntry)context);
283 /* Returns all cache entrys from the ID cache to the `ret' ID Cache List. */
285 bool silc_idcache_get_all(SilcIDCache cache, SilcIDCacheList *ret)
287 SilcIDCacheList list;
292 list = silc_idcache_list_alloc();
293 silc_hash_table_foreach(cache->id_table, silc_idcache_get_all_foreach, list);
295 if (silc_idcache_list_count(list) == 0) {
296 silc_idcache_list_free(list);
305 /* Find ID Cache entry by ID. */
307 bool silc_idcache_find_by_id(SilcIDCache cache, void *id,
308 SilcIDCacheEntry *ret)
310 return silc_hash_table_find(cache->id_table, id, NULL, (void *)ret);
313 /* Finds cache entry by context. */
315 bool silc_idcache_find_by_context(SilcIDCache cache, void *context,
316 SilcIDCacheEntry *ret)
318 return silc_hash_table_find(cache->context_table, context, NULL,
322 /* Find ID Cache entry by data. The data maybe anything that must
323 match exactly. Returns list of cache entries. */
325 bool silc_idcache_find_by_data(SilcIDCache cache, unsigned char *data,
326 unsigned int data_len, SilcIDCacheList *ret)
328 SilcIDCacheList list;
333 if (!silc_hash_table_find_all_ext(cache->data_table, data, NULL, &contexts,
334 &count, silc_hash_data, (void *)data_len,
335 silc_hash_data_compare, (void *)data_len))
343 list = silc_idcache_list_alloc();
345 for (i = 0; i < count; i++)
346 silc_idcache_list_add(list, (SilcIDCacheEntry)contexts[i]);
354 /* Find ID Cache entry by data. The data maybe anything that must
355 match exactly. Returns one cache entry. */
357 bool silc_idcache_find_by_data_one(SilcIDCache cache, unsigned char *data,
358 unsigned int data_len,
359 SilcIDCacheEntry *ret)
363 if (!silc_hash_table_find_ext(cache->data_table, data, NULL, (void *)&c,
364 silc_hash_data, (void *)data_len,
365 silc_hash_data_compare, (void *)data_len))
374 /* Allocates ID cache list. */
376 static SilcIDCacheList silc_idcache_list_alloc()
378 SilcIDCacheList list;
380 list = silc_calloc(1, sizeof(*list));
385 /* Adds cache entry to the ID cache list. If needed reallocates memory
388 static void silc_idcache_list_add(SilcIDCacheList list, SilcIDCacheEntry cache)
392 /* Try to add to static cache */
393 if (!list->cache_dyn_count)
394 for (i = 0; i < sizeof(list->cache); i++) {
395 if (!list->cache[i]) {
396 list->cache[i] = cache;
402 /* Static cache is full, allocate dynamic cache */
403 for (i = 0; i < list->cache_dyn_count; i++) {
404 if (!list->cache_dyn[i]) {
405 list->cache_dyn[i] = cache;
411 if (i >= list->cache_dyn_count) {
415 list->cache_dyn = silc_realloc(list->cache_dyn,
416 sizeof(*list->cache) * (i));
418 /* NULL the reallocated area */
419 for (k = list->cache_dyn_count; k < i; k++)
420 list->cache_dyn[k] = NULL;
422 list->cache_dyn[list->cache_dyn_count] = cache;
423 list->cache_dyn_count = i;
428 /* Returns number of cache entries in the ID cache list. */
430 int silc_idcache_list_count(SilcIDCacheList list)
432 return list->cache_count;
435 /* Returns first entry from the ID cache list. */
437 bool silc_idcache_list_first(SilcIDCacheList list, SilcIDCacheEntry *ret)
441 if (!list->cache[list->pos])
445 *ret = list->cache[list->pos];
450 /* Returns next entry from the ID cache list. */
452 bool silc_idcache_list_next(SilcIDCacheList list, SilcIDCacheEntry *ret)
457 if (list->pos >= sizeof(list->cache)) {
462 if (dyn && list->pos >= list->cache_dyn_count)
465 if (!dyn && !list->cache[list->pos])
468 if (dyn && !list->cache_dyn[list->pos])
473 *ret = list->cache[list->pos];
475 *ret = list->cache_dyn[list->pos];
481 /* Free's ID cache list. User must free the list object returned by
482 any of the searching functions. */
484 void silc_idcache_list_free(SilcIDCacheList list)
488 silc_free(list->cache_dyn);