summaryrefslogtreecommitdiff
path: root/gcache.c
blob: 5a06e0eeb26d338a97f3c4ab5e06ce62dcbb8aa8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
/* 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
 * 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.
 *
 * You should have received a copy of the GNU Lesser General Public
 * 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
 */

#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);

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,
	     GEqualFunc         key_equal_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_equal_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_equal_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)
{
  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);

  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);
  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);

  node->value = value;
  node->ref_count = 1;

  return node;
}

static void
g_cache_node_destroy (GCacheNode *node)
{
  G_LOCK (node_mem_chunk);
  g_mem_chunk_free (node_mem_chunk, node);
  G_UNLOCK (node_mem_chunk);
}