glib/gcache.c

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/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
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*
* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the GLib Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GLib Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GLib at ftp://ftp.gtk.org/pub/gtk/.
*/
/*
* MT safe
*/
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#include "glib.h"
typedef struct _GCacheNode GCacheNode;
typedef struct _GRealCache GRealCache;
struct _GCacheNode
{
/* A reference counted node */
gpointer value;
gint ref_count;
};
struct _GRealCache
{
/* Called to create a value from a key */
GCacheNewFunc value_new_func;
/* Called to destroy a value */
GCacheDestroyFunc value_destroy_func;
/* Called to duplicate a key */
GCacheDupFunc key_dup_func;
/* Called to destroy a key */
GCacheDestroyFunc key_destroy_func;
/* Associates keys with nodes */
GHashTable *key_table;
/* Associates nodes with keys */
GHashTable *value_table;
};
static GCacheNode* g_cache_node_new (gpointer value);
static void g_cache_node_destroy (GCacheNode *node);
static GMemChunk *node_mem_chunk = NULL;
G_LOCK_DEFINE_STATIC (node_mem_chunk);
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GCache*
g_cache_new (GCacheNewFunc value_new_func,
GCacheDestroyFunc value_destroy_func,
GCacheDupFunc key_dup_func,
GCacheDestroyFunc key_destroy_func,
GHashFunc hash_key_func,
GHashFunc hash_value_func,
GCompareFunc key_compare_func)
{
GRealCache *cache;
g_return_val_if_fail (value_new_func != NULL, NULL);
g_return_val_if_fail (value_destroy_func != NULL, NULL);
g_return_val_if_fail (key_dup_func != NULL, NULL);
g_return_val_if_fail (key_destroy_func != NULL, NULL);
g_return_val_if_fail (hash_key_func != NULL, NULL);
g_return_val_if_fail (hash_value_func != NULL, NULL);
g_return_val_if_fail (key_compare_func != NULL, NULL);
cache = g_new (GRealCache, 1);
cache->value_new_func = value_new_func;
cache->value_destroy_func = value_destroy_func;
cache->key_dup_func = key_dup_func;
cache->key_destroy_func = key_destroy_func;
cache->key_table = g_hash_table_new (hash_key_func, key_compare_func);
cache->value_table = g_hash_table_new (hash_value_func, NULL);
return (GCache*) cache;
}
void
g_cache_destroy (GCache *cache)
{
GRealCache *rcache;
g_return_if_fail (cache != NULL);
rcache = (GRealCache*) cache;
g_hash_table_destroy (rcache->key_table);
g_hash_table_destroy (rcache->value_table);
g_free (rcache);
}
gpointer
g_cache_insert (GCache *cache,
gpointer key)
{
GRealCache *rcache;
GCacheNode *node;
gpointer value;
g_return_val_if_fail (cache != NULL, NULL);
rcache = (GRealCache*) cache;
node = g_hash_table_lookup (rcache->key_table, key);
if (node)
{
node->ref_count += 1;
return node->value;
}
key = (* rcache->key_dup_func) (key);
value = (* rcache->value_new_func) (key);
node = g_cache_node_new (value);
g_hash_table_insert (rcache->key_table, key, node);
g_hash_table_insert (rcache->value_table, value, key);
return node->value;
}
void
g_cache_remove (GCache *cache,
gconstpointer value)
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{
GRealCache *rcache;
GCacheNode *node;
gpointer key;
g_return_if_fail (cache != NULL);
rcache = (GRealCache*) cache;
key = g_hash_table_lookup (rcache->value_table, value);
node = g_hash_table_lookup (rcache->key_table, key);
g_return_if_fail (node != NULL);
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node->ref_count -= 1;
if (node->ref_count == 0)
{
g_hash_table_remove (rcache->value_table, value);
g_hash_table_remove (rcache->key_table, key);
(* rcache->key_destroy_func) (key);
(* rcache->value_destroy_func) (node->value);
g_cache_node_destroy (node);
}
}
void
g_cache_key_foreach (GCache *cache,
GHFunc func,
gpointer user_data)
{
GRealCache *rcache;
g_return_if_fail (cache != NULL);
g_return_if_fail (func != NULL);
rcache = (GRealCache*) cache;
g_hash_table_foreach (rcache->value_table, func, user_data);
}
void
g_cache_value_foreach (GCache *cache,
GHFunc func,
gpointer user_data)
{
GRealCache *rcache;
g_return_if_fail (cache != NULL);
g_return_if_fail (func != NULL);
rcache = (GRealCache*) cache;
g_hash_table_foreach (rcache->key_table, func, user_data);
}
static GCacheNode*
g_cache_node_new (gpointer value)
{
GCacheNode *node;
G_LOCK (node_mem_chunk);
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if (!node_mem_chunk)
node_mem_chunk = g_mem_chunk_new ("cache node mem chunk", sizeof (GCacheNode),
1024, G_ALLOC_AND_FREE);
node = g_chunk_new (GCacheNode, node_mem_chunk);
G_UNLOCK (node_mem_chunk);
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node->value = value;
node->ref_count = 1;
return node;
}
static void
g_cache_node_destroy (GCacheNode *node)
{
G_LOCK (node_mem_chunk);
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g_mem_chunk_free (node_mem_chunk, node);
G_UNLOCK (node_mem_chunk);
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}