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;
47 static void g_hash_table_resize (GHashTable *hash_table);
48 static GHashNode** g_hash_table_lookup_node (GHashTable *hash_table,
50 static GHashNode* g_hash_node_new (gpointer key,
52 static void g_hash_node_destroy (GHashNode *hash_node,
53 GFreeFunc *free_func);
54 static void g_hash_nodes_destroy (GHashNode *hash_node,
55 GFreeFunc *free_func);
58 static GMemChunk *node_mem_chunk = NULL;
59 static GHashNode *node_free_list = NULL;
63 g_hash_table_new (GHashFunc hash_func,
64 GCompareFunc key_compare_func)
66 GHashTable *hash_table;
69 hash_table = g_new (GHashTable, 1);
70 hash_table->size = HASH_TABLE_MIN_SIZE;
71 hash_table->nnodes = 0;
72 hash_table->frozen = FALSE;
73 hash_table->hash_func = hash_func ? hash_func : g_direct_hash;
74 hash_table->key_compare_func = key_compare_func;
75 hash_table->nodes = g_new (GHashNode*, hash_table->size);
76 hash_table->free_func = NULL;
78 for (i = 0; i < hash_table->size; i++)
79 hash_table->nodes[i] = NULL;
85 g_hash_table_destroy (GHashTable *hash_table)
89 g_return_if_fail (hash_table != NULL);
91 for (i = 0; i < hash_table->size; i++)
92 g_hash_nodes_destroy (hash_table->nodes[i], hash_table->free_func);
94 g_free (hash_table->nodes);
98 static inline GHashNode**
99 g_hash_table_lookup_node (GHashTable *hash_table,
104 node = &hash_table->nodes
105 [(* hash_table->hash_func) (key) % hash_table->size];
107 /* Hash table lookup needs to be fast.
108 * We therefore remove the extra conditional of testing
109 * whether to call the key_compare_func or not from
112 if (hash_table->key_compare_func)
113 while (*node && !(*hash_table->key_compare_func) ((*node)->key, key))
114 node = &(*node)->next;
116 while (*node && (*node)->key != key)
117 node = &(*node)->next;
123 g_hash_table_lookup (GHashTable *hash_table,
128 g_return_val_if_fail (hash_table != NULL, NULL);
130 node = *g_hash_table_lookup_node (hash_table, key);
132 return node ? node->value : NULL;
136 g_hash_table_insert (GHashTable *hash_table,
142 g_return_if_fail (hash_table != NULL);
144 node = g_hash_table_lookup_node (hash_table, key);
148 /* do not reset node->key in this place, keeping
149 * the old key might be intended.
150 * a g_hash_table_remove/g_hash_table_insert pair
151 * can be used otherwise.
153 * node->key = key; */
154 (*node)->value = value;
158 *node = g_hash_node_new (key, value);
159 hash_table->nnodes++;
160 if (!hash_table->frozen)
161 g_hash_table_resize (hash_table);
166 g_hash_table_remove (GHashTable *hash_table,
169 GHashNode **node, *dest;
171 g_return_if_fail (hash_table != NULL);
173 while (*(node = g_hash_table_lookup_node (hash_table, key)))
176 (*node) = dest->next;
177 g_hash_node_destroy (dest, hash_table->free_func);
178 hash_table->nnodes--;
181 if (!hash_table->frozen)
182 g_hash_table_resize (hash_table);
186 g_hash_table_lookup_extended (GHashTable *hash_table,
187 gconstpointer lookup_key,
193 g_return_val_if_fail (hash_table != NULL, FALSE);
195 node = *g_hash_table_lookup_node (hash_table, lookup_key);
200 *orig_key = node->key;
202 *value = node->value;
210 g_hash_table_freeze (GHashTable *hash_table)
212 g_return_if_fail (hash_table != NULL);
214 hash_table->frozen = TRUE;
218 g_hash_table_thaw (GHashTable *hash_table)
220 g_return_if_fail (hash_table != NULL);
222 hash_table->frozen = FALSE;
224 g_hash_table_resize (hash_table);
228 g_hash_table_foreach_remove (GHashTable *hash_table,
232 GHashNode *node, *prev;
236 g_return_val_if_fail (hash_table != NULL, 0);
237 g_return_val_if_fail (func != NULL, 0);
239 for (i = 0; i < hash_table->size; i++)
245 for (node = hash_table->nodes[i]; node; prev = node, node = node->next)
247 if ((* func) (node->key, node->value, user_data))
251 hash_table->nnodes -= 1;
255 prev->next = node->next;
256 g_hash_node_destroy (node, hash_table->free_func);
261 hash_table->nodes[i] = node->next;
262 g_hash_node_destroy (node, hash_table->free_func);
269 if (!hash_table->frozen)
270 g_hash_table_resize (hash_table);
276 g_hash_table_foreach (GHashTable *hash_table,
283 g_return_if_fail (hash_table != NULL);
284 g_return_if_fail (func != NULL);
286 for (i = 0; i < hash_table->size; i++)
287 for (node = hash_table->nodes[i]; node; node = node->next)
288 (* func) (node->key, node->value, user_data);
291 /* Returns the number of elements contained in the hash table. */
293 g_hash_table_size (GHashTable *hash_table)
295 g_return_val_if_fail (hash_table != NULL, 0);
297 return hash_table->nnodes;
301 g_hash_table_set_key_freefunc (GHashTable *hash_table, GFreeFunc *free_func)
303 hash_table->free_func = free_func;
307 g_hash_table_resize (GHashTable *hash_table)
309 GHashNode **new_nodes;
312 gfloat nodes_per_list;
317 nodes_per_list = (gfloat) hash_table->nnodes / (gfloat) hash_table->size;
319 if ((nodes_per_list > 0.3 || hash_table->size <= HASH_TABLE_MIN_SIZE) &&
320 (nodes_per_list < 3.0 || hash_table->size >= HASH_TABLE_MAX_SIZE))
323 new_size = CLAMP(g_spaced_primes_closest (hash_table->nnodes),
325 HASH_TABLE_MAX_SIZE);
326 new_nodes = g_new (GHashNode*, new_size);
328 for (i = 0; i < new_size; i++)
331 for (i = 0; i < hash_table->size; i++)
332 for (node = hash_table->nodes[i]; node; node = next)
335 hash_val = (* hash_table->hash_func) (node->key) % new_size;
336 node->next = new_nodes[hash_val];
337 new_nodes[hash_val] = node;
340 g_free (hash_table->nodes);
341 hash_table->nodes = new_nodes;
342 hash_table->size = new_size;
346 g_hash_node_new (gpointer key,
349 GHashNode *hash_node;
353 hash_node = node_free_list;
354 node_free_list = node_free_list->next;
359 node_mem_chunk = g_mem_chunk_new ("hash node mem chunk",
363 hash_node = g_chunk_new (GHashNode, node_mem_chunk);
366 hash_node->key = key;
367 hash_node->value = value;
368 hash_node->next = NULL;
374 g_hash_node_destroy (GHashNode *hash_node, GFreeFunc *free_func)
376 if (free_func) (*free_func)(hash_node->key);
377 hash_node->next = node_free_list;
378 node_free_list = hash_node;
382 g_hash_nodes_destroy (GHashNode *hash_node, GFreeFunc *free_func)
393 if (free_func) (*free_func)(node->key);
397 node->next = node_free_list;
398 node_free_list = hash_node;