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 Lesser 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 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser 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.
21 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
22 * file for a list of people on the GLib Team. See the ChangeLog
23 * files for a list of changes. These files are distributed with
24 * GLib at ftp://ftp.gtk.org/pub/gtk/.
37 #define HASH_TABLE_MIN_SIZE 11
38 #define HASH_TABLE_MAX_SIZE 13845163
41 typedef struct _GHashNode GHashNode;
57 GEqualFunc key_equal_func;
58 volatile gint ref_count;
59 GDestroyNotify key_destroy_func;
60 GDestroyNotify value_destroy_func;
63 #define G_HASH_TABLE_RESIZE(hash_table) \
65 if ((hash_table->size >= 3 * hash_table->nnodes && \
66 hash_table->size > HASH_TABLE_MIN_SIZE) || \
67 (3 * hash_table->size <= hash_table->nnodes && \
68 hash_table->size < HASH_TABLE_MAX_SIZE)) \
69 g_hash_table_resize (hash_table); \
72 static void g_hash_table_resize (GHashTable *hash_table);
73 static GHashNode** g_hash_table_lookup_node (GHashTable *hash_table,
76 static GHashNode* g_hash_node_new (gpointer key,
79 static void g_hash_node_destroy (GHashNode *hash_node,
80 GDestroyNotify key_destroy_func,
81 GDestroyNotify value_destroy_func);
82 static void g_hash_nodes_destroy (GHashNode *hash_node,
83 GDestroyNotify key_destroy_func,
84 GDestroyNotify value_destroy_func);
85 static guint g_hash_table_foreach_remove_or_steal (GHashTable *hash_table,
93 * @hash_func: a function to create a hash value from a key.
94 * Hash values are used to determine where keys are stored within the
95 * #GHashTable data structure. The g_direct_hash(), g_int_hash() and
96 * g_str_hash() functions are provided for some common types of keys.
97 * If hash_func is %NULL, g_direct_hash() is used.
98 * @key_equal_func: a function to check two keys for equality. This is
99 * used when looking up keys in the #GHashTable. The g_direct_equal(),
100 * g_int_equal() and g_str_equal() functions are provided for the most
101 * common types of keys. If @key_equal_func is %NULL, keys are compared
102 * directly in a similar fashion to g_direct_equal(), but without the
103 * overhead of a function call.
105 * Creates a new #GHashTable with a reference count of 1.
107 * Return value: a new #GHashTable.
110 g_hash_table_new (GHashFunc hash_func,
111 GEqualFunc key_equal_func)
113 return g_hash_table_new_full (hash_func, key_equal_func, NULL, NULL);
118 * g_hash_table_new_full:
119 * @hash_func: a function to create a hash value from a key.
120 * @key_equal_func: a function to check two keys for equality.
121 * @key_destroy_func: a function to free the memory allocated for the key
122 * used when removing the entry from the #GHashTable or %NULL if you
123 * don't want to supply such a function.
124 * @value_destroy_func: a function to free the memory allocated for the
125 * value used when removing the entry from the #GHashTable or %NULL if
126 * you don't want to supply such a function.
128 * Creates a new #GHashTable like g_hash_table_new() with a reference count
129 * of 1 and allows to specify functions to free the memory allocated for the
130 * key and value that get called when removing the entry from the #GHashTable.
132 * Return value: a new #GHashTable.
135 g_hash_table_new_full (GHashFunc hash_func,
136 GEqualFunc key_equal_func,
137 GDestroyNotify key_destroy_func,
138 GDestroyNotify value_destroy_func)
140 GHashTable *hash_table;
142 hash_table = g_slice_new (GHashTable);
143 hash_table->size = HASH_TABLE_MIN_SIZE;
144 hash_table->nnodes = 0;
145 hash_table->hash_func = hash_func ? hash_func : g_direct_hash;
146 hash_table->key_equal_func = key_equal_func;
147 hash_table->ref_count = 1;
148 hash_table->key_destroy_func = key_destroy_func;
149 hash_table->value_destroy_func = value_destroy_func;
150 hash_table->nodes = g_new0 (GHashNode*, hash_table->size);
158 * @hash_table: a valid #GHashTable.
160 * Atomically increments the reference count of @hash_table by one.
161 * This function is MT-safe and may be called from any thread.
163 * Return value: the passed in #GHashTable.
168 g_hash_table_ref (GHashTable *hash_table)
170 g_return_val_if_fail (hash_table != NULL, NULL);
171 g_return_val_if_fail (hash_table->ref_count > 0, hash_table);
173 g_atomic_int_add (&hash_table->ref_count, 1);
178 * g_hash_table_unref:
179 * @hash_table: a valid #GHashTable.
181 * Atomically decrements the reference count of @hash_table by one.
182 * If the reference count drops to 0, all keys and values will be
183 * destroyed, and all memory allocated by the hash table is released.
184 * This function is MT-safe and may be called from any thread.
189 g_hash_table_unref (GHashTable *hash_table)
191 g_return_if_fail (hash_table != NULL);
192 g_return_if_fail (hash_table->ref_count > 0);
194 if (g_atomic_int_exchange_and_add (&hash_table->ref_count, -1) - 1 == 0)
198 for (i = 0; i < hash_table->size; i++)
199 g_hash_nodes_destroy (hash_table->nodes[i],
200 hash_table->key_destroy_func,
201 hash_table->value_destroy_func);
202 g_free (hash_table->nodes);
203 g_slice_free (GHashTable, hash_table);
208 * g_hash_table_destroy:
209 * @hash_table: a #GHashTable.
211 * Destroys all keys and values in the #GHashTable and decrements its
212 * reference count by 1. If keys and/or values are dynamically allocated,
213 * you should either free them first or create the #GHashTable with destroy
214 * notifiers using g_hash_table_new_full(). In the latter case the destroy
215 * functions you supplied will be called on all keys and values during the
219 g_hash_table_destroy (GHashTable *hash_table)
221 g_return_if_fail (hash_table != NULL);
222 g_return_if_fail (hash_table->ref_count > 0);
224 g_hash_table_remove_all (hash_table);
225 g_hash_table_unref (hash_table);
228 static inline GHashNode**
229 g_hash_table_lookup_node (GHashTable *hash_table,
236 hash_value = (* hash_table->hash_func) (key);
237 node = &hash_table->nodes[hash_value % hash_table->size];
240 *hash_return = hash_value;
242 /* Hash table lookup needs to be fast.
243 * We therefore remove the extra conditional of testing
244 * whether to call the key_equal_func or not from
247 * Additional optimisation: first check if our full hash
248 * values are equal so we can avoid calling the full-blown
249 * key equality function in most cases.
251 if (hash_table->key_equal_func)
252 while (*node && (((*node)->key_hash != hash_value) ||
253 !(*hash_table->key_equal_func) ((*node)->key, key)))
254 node = &(*node)->next;
256 while (*node && (*node)->key != key)
257 node = &(*node)->next;
263 * g_hash_table_lookup:
264 * @hash_table: a #GHashTable.
265 * @key: the key to look up.
267 * Looks up a key in a #GHashTable. Note that this function cannot
268 * distinguish between a key that is not present and one which is present
269 * and has the value %NULL. If you need this distinction, use
270 * g_hash_table_lookup_extended().
272 * Return value: the associated value, or %NULL if the key is not found.
275 g_hash_table_lookup (GHashTable *hash_table,
280 g_return_val_if_fail (hash_table != NULL, NULL);
282 node = *g_hash_table_lookup_node (hash_table, key, NULL);
284 return node ? node->value : NULL;
288 * g_hash_table_lookup_extended:
289 * @hash_table: a #GHashTable.
290 * @lookup_key: the key to look up.
291 * @orig_key: returns the original key.
292 * @value: returns the value associated with the key.
294 * Looks up a key in the #GHashTable, returning the original key and the
295 * associated value and a #gboolean which is %TRUE if the key was found. This
296 * is useful if you need to free the memory allocated for the original key,
297 * for example before calling g_hash_table_remove().
299 * Return value: %TRUE if the key was found in the #GHashTable.
302 g_hash_table_lookup_extended (GHashTable *hash_table,
303 gconstpointer lookup_key,
309 g_return_val_if_fail (hash_table != NULL, FALSE);
311 node = *g_hash_table_lookup_node (hash_table, lookup_key, NULL);
316 *orig_key = node->key;
318 *value = node->value;
326 g_hash_table_insert_internal (GHashTable *hash_table,
329 gboolean keep_new_key)
334 g_return_if_fail (hash_table != NULL);
335 g_return_if_fail (hash_table->ref_count > 0);
337 node = g_hash_table_lookup_node (hash_table, key, &key_hash);
341 if (hash_table->key_destroy_func)
344 hash_table->key_destroy_func ((*node)->key);
346 hash_table->key_destroy_func (key);
349 if (hash_table->value_destroy_func)
350 hash_table->value_destroy_func ((*node)->value);
352 (*node)->value = value;
356 *node = g_hash_node_new (key, value, key_hash);
357 hash_table->nnodes++;
358 G_HASH_TABLE_RESIZE (hash_table);
363 * g_hash_table_insert:
364 * @hash_table: a #GHashTable.
365 * @key: a key to insert.
366 * @value: the value to associate with the key.
368 * Inserts a new key and value into a #GHashTable.
370 * If the key already exists in the #GHashTable its current value is replaced
371 * with the new value. If you supplied a @value_destroy_func when creating the
372 * #GHashTable, the old value is freed using that function. If you supplied
373 * a @key_destroy_func when creating the #GHashTable, the passed key is freed
374 * using that function.
377 g_hash_table_insert (GHashTable *hash_table,
381 return g_hash_table_insert_internal (hash_table, key, value, FALSE);
385 * g_hash_table_replace:
386 * @hash_table: a #GHashTable.
387 * @key: a key to insert.
388 * @value: the value to associate with the key.
390 * Inserts a new key and value into a #GHashTable similar to
391 * g_hash_table_insert(). The difference is that if the key already exists
392 * in the #GHashTable, it gets replaced by the new key. If you supplied a
393 * @value_destroy_func when creating the #GHashTable, the old value is freed
394 * using that function. If you supplied a @key_destroy_func when creating the
395 * #GHashTable, the old key is freed using that function.
398 g_hash_table_replace (GHashTable *hash_table,
402 return g_hash_table_insert_internal (hash_table, key, value, TRUE);
406 * g_hash_table_remove:
407 * @hash_table: a #GHashTable.
408 * @key: the key to remove.
410 * Removes a key and its associated value from a #GHashTable.
412 * If the #GHashTable was created using g_hash_table_new_full(), the
413 * key and value are freed using the supplied destroy functions, otherwise
414 * you have to make sure that any dynamically allocated values are freed
417 * Return value: %TRUE if the key was found and removed from the #GHashTable.
420 g_hash_table_remove (GHashTable *hash_table,
423 GHashNode **node, *dest;
425 g_return_val_if_fail (hash_table != NULL, FALSE);
427 node = g_hash_table_lookup_node (hash_table, key, NULL);
431 (*node) = dest->next;
432 g_hash_node_destroy (dest,
433 hash_table->key_destroy_func,
434 hash_table->value_destroy_func);
435 hash_table->nnodes--;
437 G_HASH_TABLE_RESIZE (hash_table);
446 * g_hash_table_remove_all:
447 * @hash_table: a #GHashTable
449 * Removes all keys and their associated values from a #GHashTable.
451 * If the #GHashTable was created using g_hash_table_new_full(), the keys
452 * and values are freed using the supplied destroy functions, otherwise you
453 * have to make sure that any dynamically allocated values are freed
459 g_hash_table_remove_all (GHashTable *hash_table)
463 g_return_if_fail (hash_table != NULL);
465 for (i = 0; i < hash_table->size; i++)
467 g_hash_nodes_destroy (hash_table->nodes[i],
468 hash_table->key_destroy_func,
469 hash_table->value_destroy_func);
470 hash_table->nodes[i] = NULL;
472 hash_table->nnodes = 0;
474 G_HASH_TABLE_RESIZE (hash_table);
478 * g_hash_table_steal:
479 * @hash_table: a #GHashTable.
480 * @key: the key to remove.
482 * Removes a key and its associated value from a #GHashTable without
483 * calling the key and value destroy functions.
485 * Return value: %TRUE if the key was found and removed from the #GHashTable.
488 g_hash_table_steal (GHashTable *hash_table,
491 GHashNode **node, *dest;
493 g_return_val_if_fail (hash_table != NULL, FALSE);
495 node = g_hash_table_lookup_node (hash_table, key, NULL);
499 (*node) = dest->next;
500 g_hash_node_destroy (dest, NULL, NULL);
501 hash_table->nnodes--;
503 G_HASH_TABLE_RESIZE (hash_table);
512 * g_hash_table_steal_all:
513 * @hash_table: a #GHashTable.
515 * Removes all keys and their associated values from a #GHashTable
516 * without calling the key and value destroy functions.
521 g_hash_table_steal_all (GHashTable *hash_table)
525 g_return_if_fail (hash_table != NULL);
527 for (i = 0; i < hash_table->size; i++)
529 g_hash_nodes_destroy (hash_table->nodes[i], NULL, NULL);
530 hash_table->nodes[i] = NULL;
533 hash_table->nnodes = 0;
535 G_HASH_TABLE_RESIZE (hash_table);
539 * g_hash_table_foreach_remove:
540 * @hash_table: a #GHashTable.
541 * @func: the function to call for each key/value pair.
542 * @user_data: user data to pass to the function.
544 * Calls the given function for each key/value pair in the #GHashTable.
545 * If the function returns %TRUE, then the key/value pair is removed from the
546 * #GHashTable. If you supplied key or value destroy functions when creating
547 * the #GHashTable, they are used to free the memory allocated for the removed
550 * Return value: the number of key/value pairs removed.
553 g_hash_table_foreach_remove (GHashTable *hash_table,
557 g_return_val_if_fail (hash_table != NULL, 0);
558 g_return_val_if_fail (func != NULL, 0);
560 return g_hash_table_foreach_remove_or_steal (hash_table, func, user_data, TRUE);
564 * g_hash_table_foreach_steal:
565 * @hash_table: a #GHashTable.
566 * @func: the function to call for each key/value pair.
567 * @user_data: user data to pass to the function.
569 * Calls the given function for each key/value pair in the #GHashTable.
570 * If the function returns %TRUE, then the key/value pair is removed from the
571 * #GHashTable, but no key or value destroy functions are called.
573 * Return value: the number of key/value pairs removed.
576 g_hash_table_foreach_steal (GHashTable *hash_table,
580 g_return_val_if_fail (hash_table != NULL, 0);
581 g_return_val_if_fail (func != NULL, 0);
583 return g_hash_table_foreach_remove_or_steal (hash_table, func, user_data, FALSE);
587 g_hash_table_foreach_remove_or_steal (GHashTable *hash_table,
592 GHashNode *node, *prev;
596 for (i = 0; i < hash_table->size; i++)
602 for (node = hash_table->nodes[i]; node; prev = node, node = node->next)
604 if ((* func) (node->key, node->value, user_data))
608 hash_table->nnodes -= 1;
612 prev->next = node->next;
613 g_hash_node_destroy (node,
614 notify ? hash_table->key_destroy_func : NULL,
615 notify ? hash_table->value_destroy_func : NULL);
620 hash_table->nodes[i] = node->next;
621 g_hash_node_destroy (node,
622 notify ? hash_table->key_destroy_func : NULL,
623 notify ? hash_table->value_destroy_func : NULL);
630 G_HASH_TABLE_RESIZE (hash_table);
636 * g_hash_table_foreach:
637 * @hash_table: a #GHashTable.
638 * @func: the function to call for each key/value pair.
639 * @user_data: user data to pass to the function.
641 * Calls the given function for each of the key/value pairs in the
642 * #GHashTable. The function is passed the key and value of each
643 * pair, and the given @user_data parameter. The hash table may not
644 * be modified while iterating over it (you can't add/remove
645 * items). To remove all items matching a predicate, use
646 * g_hash_table_foreach_remove().
648 * See g_hash_table_find() for performance caveats for linear
649 * order searches in contrast to g_hash_table_lookup().
652 g_hash_table_foreach (GHashTable *hash_table,
659 g_return_if_fail (hash_table != NULL);
660 g_return_if_fail (func != NULL);
662 for (i = 0; i < hash_table->size; i++)
663 for (node = hash_table->nodes[i]; node; node = node->next)
664 (* func) (node->key, node->value, user_data);
669 * @hash_table: a #GHashTable.
670 * @predicate: function to test the key/value pairs for a certain property.
671 * @user_data: user data to pass to the function.
673 * Calls the given function for key/value pairs in the #GHashTable until
674 * @predicate returns %TRUE. The function is passed the key and value of
675 * each pair, and the given @user_data parameter. The hash table may not
676 * be modified while iterating over it (you can't add/remove items).
678 * Note, that hash tables are really only optimized for forward lookups,
679 * i.e. g_hash_table_lookup().
680 * So code that frequently issues g_hash_table_find() or
681 * g_hash_table_foreach() (e.g. in the order of once per every entry in a
682 * hash table) should probably be reworked to use additional or different
683 * data structures for reverse lookups (keep in mind that an O(n) find/foreach
684 * operation issued for all n values in a hash table ends up needing O(n*n)
687 * Return value: The value of the first key/value pair is returned, for which
688 * func evaluates to %TRUE. If no pair with the requested property is found,
694 g_hash_table_find (GHashTable *hash_table,
701 g_return_val_if_fail (hash_table != NULL, NULL);
702 g_return_val_if_fail (predicate != NULL, NULL);
704 for (i = 0; i < hash_table->size; i++)
705 for (node = hash_table->nodes[i]; node; node = node->next)
706 if (predicate (node->key, node->value, user_data))
713 * @hash_table: a #GHashTable.
715 * Returns the number of elements contained in the #GHashTable.
717 * Return value: the number of key/value pairs in the #GHashTable.
720 g_hash_table_size (GHashTable *hash_table)
722 g_return_val_if_fail (hash_table != NULL, 0);
724 return hash_table->nnodes;
728 * g_hash_table_get_keys:
729 * @hash_table: a #GHashTable
731 * Retrieves every key inside @hash_table. The returned data is valid
732 * until @hash_table is modified.
734 * Return value: a #GList containing all the keys inside the hash
735 * table. The content of the list is owned by the hash table and
736 * should not be modified or freed. Use g_list_free() when done
742 g_hash_table_get_keys (GHashTable *hash_table)
748 g_return_val_if_fail (hash_table != NULL, NULL);
751 for (i = 0; i < hash_table->size; i++)
752 for (node = hash_table->nodes[i]; node; node = node->next)
753 retval = g_list_prepend (retval, node->key);
759 * g_hash_table_get_values:
760 * @hash_table: a #GHashTable
762 * Retrieves every value inside @hash_table. The returned data is
763 * valid until @hash_table is modified.
765 * Return value: a #GList containing all the values inside the hash
766 * table. The content of the list is owned by the hash table and
767 * should not be modified or freed. Use g_list_free() when done
773 g_hash_table_get_values (GHashTable *hash_table)
779 g_return_val_if_fail (hash_table != NULL, NULL);
782 for (i = 0; i < hash_table->size; i++)
783 for (node = hash_table->nodes[i]; node; node = node->next)
784 retval = g_list_prepend (retval, node->value);
790 g_hash_table_resize (GHashTable *hash_table)
792 GHashNode **new_nodes;
799 new_size = g_spaced_primes_closest (hash_table->nnodes);
800 new_size = CLAMP (new_size, HASH_TABLE_MIN_SIZE, HASH_TABLE_MAX_SIZE);
802 new_nodes = g_new0 (GHashNode*, new_size);
804 for (i = 0; i < hash_table->size; i++)
805 for (node = hash_table->nodes[i]; node; node = next)
809 hash_val = node->key_hash % new_size;
811 node->next = new_nodes[hash_val];
812 new_nodes[hash_val] = node;
815 g_free (hash_table->nodes);
816 hash_table->nodes = new_nodes;
817 hash_table->size = new_size;
821 g_hash_node_new (gpointer key,
825 GHashNode *hash_node = g_slice_new (GHashNode);
827 hash_node->key = key;
828 hash_node->value = value;
829 hash_node->key_hash = key_hash;
830 hash_node->next = NULL;
836 g_hash_node_destroy (GHashNode *hash_node,
837 GDestroyNotify key_destroy_func,
838 GDestroyNotify value_destroy_func)
840 if (key_destroy_func)
841 key_destroy_func (hash_node->key);
842 if (value_destroy_func)
843 value_destroy_func (hash_node->value);
844 g_slice_free (GHashNode, hash_node);
848 g_hash_nodes_destroy (GHashNode *hash_node,
849 GFreeFunc key_destroy_func,
850 GFreeFunc value_destroy_func)
854 GHashNode *next = hash_node->next;
855 if (key_destroy_func)
856 key_destroy_func (hash_node->key);
857 if (value_destroy_func)
858 value_destroy_func (hash_node->value);
859 g_slice_free (GHashNode, hash_node);
866 #include "galiasdef.c"