1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
22 #define HASH_TABLE_MIN_SIZE 11
23 #define HASH_TABLE_MAX_SIZE 13845163
26 typedef struct _GHashNode GHashNode;
42 GCompareFunc key_compare_func;
46 static void g_hash_table_resize (GHashTable *hash_table);
47 static GHashNode** g_hash_table_lookup_node(GHashTable *hash_table,
49 static GHashNode* g_hash_node_new (gpointer key,
51 static void g_hash_node_destroy (GHashNode *hash_node);
52 static void g_hash_nodes_destroy (GHashNode *hash_node);
55 static GMemChunk *node_mem_chunk = NULL;
56 static GHashNode *node_free_list = NULL;
60 g_hash_table_new (GHashFunc hash_func,
61 GCompareFunc key_compare_func)
63 GHashTable *hash_table;
66 hash_table = g_new (GHashTable, 1);
67 hash_table->size = HASH_TABLE_MIN_SIZE;
68 hash_table->nnodes = 0;
69 hash_table->frozen = FALSE;
70 hash_table->hash_func = hash_func ? hash_func : g_direct_hash;
71 hash_table->key_compare_func = key_compare_func;
72 hash_table->nodes = g_new (GHashNode*, hash_table->size);
74 for (i = 0; i < hash_table->size; i++)
75 hash_table->nodes[i] = NULL;
81 g_hash_table_destroy (GHashTable *hash_table)
85 g_return_if_fail (hash_table);
87 for (i = 0; i < hash_table->size; i++)
88 g_hash_nodes_destroy (hash_table->nodes[i]);
90 g_free (hash_table->nodes);
95 g_hash_table_insert (GHashTable *hash_table,
101 g_return_if_fail (hash_table);
103 node = g_hash_table_lookup_node (hash_table, key);
107 /* do not reset node->key in this place, keeping
108 * the old key might be intended.
109 * a g_hash_table_remove/g_hash_table_insert pair
110 * can be used otherwise.
112 * node->key = key; */
113 (*node)->value = value;
117 *node = g_hash_node_new (key, value);
118 hash_table->nnodes++;
119 if (!hash_table->frozen)
120 g_hash_table_resize (hash_table);
125 g_hash_table_remove (GHashTable *hash_table,
128 GHashNode **node, *dest;
130 g_return_if_fail (hash_table);
132 while (*(node = g_hash_table_lookup_node (hash_table, key)))
135 (*node) = dest->next;
136 g_hash_node_destroy (dest);
137 hash_table->nnodes--;
139 if (!hash_table->frozen)
140 g_hash_table_resize (hash_table);
144 g_hash_table_lookup (GHashTable *hash_table,
149 g_return_val_if_fail (hash_table, NULL);
151 node = *g_hash_table_lookup_node (hash_table, key);
152 return node ? node->value : NULL;
156 g_hash_table_lookup_extended (GHashTable *hash_table,
157 gconstpointer lookup_key,
163 g_return_val_if_fail (hash_table, FALSE);
165 node = *g_hash_table_lookup_node (hash_table, lookup_key);
170 *orig_key = node->key;
172 *value = node->value;
180 g_hash_table_freeze (GHashTable *hash_table)
182 g_return_if_fail (hash_table);
184 hash_table->frozen = TRUE;
188 g_hash_table_thaw (GHashTable *hash_table)
190 g_return_if_fail (hash_table);
192 hash_table->frozen = FALSE;
194 g_hash_table_resize (hash_table);
198 g_hash_table_foreach (GHashTable *hash_table,
205 g_return_if_fail (hash_table);
207 for (i = 0; i < hash_table->size; i++)
208 for (node = hash_table->nodes[i]; node; node = node->next)
209 (* func) (node->key, node->value, user_data);
212 /* Returns the number of elements contained in the hash table. */
213 gint g_hash_table_size (GHashTable *hash_table)
215 g_return_val_if_fail (hash_table, 0);
217 return hash_table->nnodes;
221 g_hash_table_resize (GHashTable *hash_table)
223 GHashNode **new_nodes;
226 gfloat nodes_per_list;
231 g_return_if_fail (hash_table);
233 nodes_per_list = (gfloat) hash_table->nnodes / (gfloat) hash_table->size;
235 if ((nodes_per_list > 0.3 || hash_table->size <= HASH_TABLE_MIN_SIZE) &&
236 (nodes_per_list < 3.0 || hash_table->size >= HASH_TABLE_MAX_SIZE))
239 new_size = CLAMP(g_spaced_primes_closest (hash_table->nnodes),
241 HASH_TABLE_MAX_SIZE);
242 new_nodes = g_new (GHashNode*, new_size);
244 for (i = 0; i < new_size; i++)
247 for (i = 0; i < hash_table->size; i++)
248 for (node = hash_table->nodes[i]; node; node = next)
251 hash_val = (* hash_table->hash_func) (node->key) % new_size;
252 node->next = new_nodes[hash_val];
253 new_nodes[hash_val] = node;
256 g_free (hash_table->nodes);
257 hash_table->nodes = new_nodes;
258 hash_table->size = new_size;
262 g_hash_table_lookup_node (GHashTable *hash_table,
267 g_return_val_if_fail (hash_table, NULL);
269 node = &hash_table->nodes
270 [(* hash_table->hash_func) (key) % hash_table->size];
272 /* Hash table lookup needs to be fast.
273 * We therefore remove the extra conditional of testing
274 * whether to call the key_compare_func or not from
277 if (hash_table->key_compare_func)
278 while (*node && !(*hash_table->key_compare_func) ((*node)->key, key))
279 node = &(*node)->next;
281 while (*node && (*node)->key != key)
282 node = &(*node)->next;
288 g_hash_node_new (gpointer key,
291 GHashNode *hash_node;
295 hash_node = node_free_list;
296 node_free_list = node_free_list->next;
301 node_mem_chunk = g_mem_chunk_new ("hash node mem chunk",
305 hash_node = g_chunk_new (GHashNode, node_mem_chunk);
308 hash_node->key = key;
309 hash_node->value = value;
310 hash_node->next = NULL;
316 g_hash_node_destroy (GHashNode *hash_node)
318 g_return_if_fail (hash_node);
320 hash_node->next = node_free_list;
321 node_free_list = hash_node;
325 g_hash_nodes_destroy (GHashNode *hash_node)
337 node->next = node_free_list;
338 node_free_list = hash_node;