/*
* This file is part of DisOrder
- * Copyright (C) 2006 Richard Kettlewell
+ * Copyright (C) 2006-2008 Richard Kettlewell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
+/** @file lib/cache.c @brief Object caching */
#include <config.h>
#include "types.h"
#include "log.h"
#include "cache.h"
+/** @brief The global cache */
static hash *h;
+/** @brief One cache entry */
struct cache_entry {
+ /** @brief What type of object this is */
const struct cache_type *type;
+
+ /** @brief Pointer to object value */
const void *value;
+
+ /** @brief Time that object was inserted into cache */
time_t birth;
};
+/** @brief Return true if object @p c has expired */
static int expired(const struct cache_entry *c, time_t now) {
return now - c->birth > c->type->lifetime;
}
+/** @brief Insert an object into the cache
+ * @param type Pointer to object type
+ * @param key Unique key
+ * @param value Pointer to value
+ */
void cache_put(const struct cache_type *type,
const char *key, const void *value) {
struct cache_entry *c;
hash_add(h, key, c, HASH_INSERT_OR_REPLACE);
}
+/** @brief Look up an object in the cache
+ * @param type Pointer to object type
+ * @param key Unique key
+ * @return Pointer to object value or NULL if not found
+ */
const void *cache_get(const struct cache_type *type, const char *key) {
const struct cache_entry *c;
return 0;
}
+/** @brief Call used by from cache_expire() */
static int expiry_callback(const char *key, void *value, void *u) {
const struct cache_entry *c = value;
const time_t *now = u;
return 0;
}
+/** @brief Expire the cache
+ *
+ * Called from time to time to expire cache entries. */
void cache_expire(void) {
time_t now;
}
}
+/** @brief Callback used by cache_clean() */
static int clean_callback(const char *key, void *value, void *u) {
const struct cache_entry *c = value;
const struct cache_type *type = u;
return 0;
}
+/** @brief Clean the cache
+ * @param type Pointer to type to clean
+ *
+ * Removes all entries of type @p type from the cache.
+ */
void cache_clean(const struct cache_type *type) {
if(h)
hash_foreach(h, clean_callback, (void *)type);
}
+/** @brief Report cache size
+ *
+ * Returns the number of objects in the cache
+ */
size_t cache_count(void) {
return h ? hash_count(h) : 0;
}