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 2 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, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * 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, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  18  * USA
  19  */
  20 /** @file lib/cache.h
  21  * @brief Object caching
  22  *
  23  * There is a single cache for the whole process.  Objects of different types
  24  * are distinguished.  Objects might be thrown out of the cache at any point.
  25  */
  26
  27 #ifndef CACHE_H
  28 #define CACHE_H
  29
  30 /* Defines a cache mapping keys to typed data items */
  31
  32 /** @brief Type of a cache object */
  33 struct cache_type {
  34   /** @brief Lifetime for objects of this type (seconds) */
  35   int lifetime;
  36 };
  37
  38 void cache_put(const struct cache_type *type,
  39                const char *key, const void *value);
  40 /* Inserts KEY into the cache with value VALUE.  If KEY is already
  41  * present it is overwritten. */
  42
  43 const void *cache_get(const struct cache_type *type, const char *key);
  44 /* Get a value from the cache. */
  45
  46 void cache_expire(void);
  47 /* Expire values from the cache */
  48
  49 void cache_clean(const struct cache_type *type);
  50 /* Clean all elements of a particular type, or all elements if TYPE=0 */
  51
  52 size_t cache_count(void);
  53 /* Return the size of the cache */
  54
  55 #endif /* CACHE_H */
  56
  57 /*
  58 Local Variables:
  59 c-basic-offset:2
  60 comment-column:40
  61 fill-column:79
  62 indent-tabs-mode:nil
  63 End:
  64 */