mdw@git.distorted.org.uk Git - disorder/blob - lib/cache.h

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2006-2008 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/cache.h
  19  * @brief Object caching
  20  *
  21  * There is a single cache for the whole process.  Objects of different types
  22  * are distinguished.  Objects might be thrown out of the cache at any point.
  23  */
  24
  25 #ifndef CACHE_H
  26 #define CACHE_H
  27
  28 /* Defines a cache mapping keys to typed data items */
  29
  30 /** @brief Type of a cache object */
  31 struct cache_type {
  32   /** @brief Lifetime for objects of this type (seconds) */
  33   int lifetime;
  34 };
  35
  36 void cache_put(const struct cache_type *type,
  37                const char *key, const void *value);
  38 /* Inserts KEY into the cache with value VALUE.  If KEY is already
  39  * present it is overwritten. */
  40
  41 const void *cache_get(const struct cache_type *type, const char *key);
  42 /* Get a value from the cache. */
  43
  44 void cache_expire(void);
  45 /* Expire values from the cache */
  46
  47 void cache_clean(const struct cache_type *type);
  48 /* Clean all elements of a particular type, or all elements if TYPE=0 */
  49
  50 size_t cache_count(void);
  51 /* Return the size of the cache */
  52
  53 #endif /* CACHE_H */
  54
  55 /*
  56 Local Variables:
  57 c-basic-offset:2
  58 comment-column:40
  59 fill-column:79
  60 indent-tabs-mode:nil
  61 End:
  62 */