1 /* GLIB - Library of useful routines for C programming

     2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald

     3  * Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

     4  *

     5  * This library is free software; you can redistribute it and/or

     6  * modify it under the terms of the GNU Lesser General Public

     7  * License as published by the Free Software Foundation; either

     8  * version 2 of the License, or (at your option) any later version.

     9  *

    10  * This library 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 GNU

    13  * Lesser General Public License for more details.

    14  *

    15  * You should have received a copy of the GNU Lesser General Public

    16  * License along with this library; if not, write to the

    17  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

    18  * Boston, MA 02111-1307, USA.

    19  */

    20 

    21 /*

    22  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS

    23  * file for a list of people on the GLib Team.  See the ChangeLog

    24  * files for a list of changes.  These files are distributed with

    25  * GLib at ftp://ftp.gtk.org/pub/gtk/. 

    26  */

    27 

    28 /* 

    29  * MT safe

    30  */

    31 

    32 #include "config.h"

    33 

    34 #include "glib.h"

    35 #include "galias.h"

    36 

    37 

    38 typedef struct _GCacheNode  GCacheNode;

    39 

    40 struct _GCacheNode

    41 {

    42   /* A reference counted node */

    43   gpointer value;

    44   gint ref_count;

    45 };

    46 

    47 struct _GCache

    48 {

    49   /* Called to create a value from a key */

    50   GCacheNewFunc value_new_func;

    51 

    52   /* Called to destroy a value */

    53   GCacheDestroyFunc value_destroy_func;

    54 

    55   /* Called to duplicate a key */

    56   GCacheDupFunc key_dup_func;

    57 

    58   /* Called to destroy a key */

    59   GCacheDestroyFunc key_destroy_func;

    60 

    61   /* Associates keys with nodes */

    62   GHashTable *key_table;

    63 

    64   /* Associates nodes with keys */

    65   GHashTable *value_table;

    66 };

    67 

    68 static inline GCacheNode*

    69 g_cache_node_new (gpointer value)

    70 {

    71   GCacheNode *node = g_slice_new (GCacheNode);

    72   node->value = value;

    73   node->ref_count = 1;

    74   return node;

    75 }

    76 

    77 static inline void

    78 g_cache_node_destroy (GCacheNode *node)

    79 {

    80   g_slice_free (GCacheNode, node);

    81 }

    82 

    83 EXPORT_C GCache*

    84 g_cache_new (GCacheNewFunc      value_new_func,

    85 	     GCacheDestroyFunc  value_destroy_func,

    86 	     GCacheDupFunc      key_dup_func,

    87 	     GCacheDestroyFunc  key_destroy_func,

    88 	     GHashFunc          hash_key_func,

    89 	     GHashFunc          hash_value_func,

    90 	     GEqualFunc         key_equal_func)

    91 {

    92   GCache *cache;

    93 

    94   g_return_val_if_fail (value_new_func != NULL, NULL);

    95   g_return_val_if_fail (value_destroy_func != NULL, NULL);

    96   g_return_val_if_fail (key_dup_func != NULL, NULL);

    97   g_return_val_if_fail (key_destroy_func != NULL, NULL);

    98   g_return_val_if_fail (hash_key_func != NULL, NULL);

    99   g_return_val_if_fail (hash_value_func != NULL, NULL);

   100   g_return_val_if_fail (key_equal_func != NULL, NULL);

   101 

   102   cache = g_slice_new (GCache);

   103   

   104   cache->value_new_func = value_new_func;

   105   cache->value_destroy_func = value_destroy_func;

   106   cache->key_dup_func = key_dup_func;

   107   cache->key_destroy_func = key_destroy_func;

   108   cache->key_table = g_hash_table_new (hash_key_func, key_equal_func);

   109   cache->value_table = g_hash_table_new (hash_value_func, NULL);

   110 

   111   return cache;

   112 }

   113 

   114 EXPORT_C void

   115 g_cache_destroy (GCache *cache)

   116 {

   117   g_return_if_fail (cache != NULL);

   118 

   119   g_hash_table_destroy (cache->key_table);

   120   g_hash_table_destroy (cache->value_table);

   121   g_slice_free (GCache, cache);

   122 }

   123 

   124 EXPORT_C gpointer

   125 g_cache_insert (GCache   *cache,

   126 		gpointer  key)

   127 {

   128   GCacheNode *node;

   129   gpointer value;

   130 

   131   g_return_val_if_fail (cache != NULL, NULL);

   132 

   133   node = g_hash_table_lookup (cache->key_table, key);

   134   if (node)

   135     {

   136       node->ref_count += 1;

   137       return node->value;

   138     }

   139 

   140   key = (* cache->key_dup_func) (key);

   141   value = (* cache->value_new_func) (key);

   142   node = g_cache_node_new (value);

   143 

   144   g_hash_table_insert (cache->key_table, key, node);

   145   g_hash_table_insert (cache->value_table, value, key);

   146 

   147   return node->value;

   148 }

   149 

   150 EXPORT_C void

   151 g_cache_remove (GCache        *cache,

   152 		gconstpointer  value)

   153 {

   154   GCacheNode *node;

   155   gpointer key;

   156 

   157   g_return_if_fail (cache != NULL);

   158 

   159   key = g_hash_table_lookup (cache->value_table, value);

   160   node = g_hash_table_lookup (cache->key_table, key);

   161 

   162   g_return_if_fail (node != NULL);

   163 

   164   node->ref_count -= 1;

   165   if (node->ref_count == 0)

   166     {

   167       g_hash_table_remove (cache->value_table, value);

   168       g_hash_table_remove (cache->key_table, key);

   169 

   170       (* cache->key_destroy_func) (key);

   171       (* cache->value_destroy_func) (node->value);

   172       g_cache_node_destroy (node);

   173     }

   174 }

   175 

   176 EXPORT_C void

   177 g_cache_key_foreach (GCache   *cache,

   178 		     GHFunc    func,

   179 		     gpointer  user_data)

   180 {

   181   g_return_if_fail (cache != NULL);

   182   g_return_if_fail (func != NULL);

   183 

   184   g_hash_table_foreach (cache->value_table, func, user_data);

   185 }

   186 

   187 EXPORT_C void

   188 g_cache_value_foreach (GCache   *cache,

   189 		       GHFunc    func,

   190 		       gpointer  user_data)

   191 {

   192   g_return_if_fail (cache != NULL);

   193   g_return_if_fail (func != NULL);

   194 

   195   g_hash_table_foreach (cache->key_table, func, user_data);

   196 }

   197 

   198 #define __G_CACHE_C__

   199 #include "galiasdef.c"