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/.
33 #include <string.h> /* memset */
38 #define HASH_TABLE_MIN_SHIFT 3 /* 1 << 3 == 8 buckets */
40 typedef struct _GHashNode GHashNode;
47 /* If key_hash == 0, node is not in use
48 * If key_hash == 1, node is a tombstone
49 * If key_hash >= 2, node contains data */
59 gint noccupied; /* nnodes + tombstones */
62 GEqualFunc key_equal_func;
63 volatile gint ref_count;
64 #ifndef G_DISABLE_ASSERT
66 * Tracks the structure of the hash table, not its contents: is only
67 * incremented when a node is added or removed (is not incremented
68 * when the key or data of a node is modified).
72 GDestroyNotify key_destroy_func;
73 GDestroyNotify value_destroy_func;
78 GHashTable *hash_table;
86 /* Each table size has an associated prime modulo (the first prime
87 * lower than the table size) used to find the initial bucket. Probing
88 * then works modulo 2^n. The prime modulo is necessary to get a
89 * good distribution with poor hash functions. */
90 static const gint prime_mod [] =
108 65521, /* For 1 << 16 */
123 2147483647 /* For 1 << 31 */
127 g_hash_table_set_shift (GHashTable *hash_table, gint shift)
132 hash_table->size = 1 << shift;
133 hash_table->mod = prime_mod [shift];
135 for (i = 0; i < shift; i++)
141 hash_table->mask = mask;
145 g_hash_table_find_closest_shift (gint n)
156 g_hash_table_set_shift_from_size (GHashTable *hash_table, gint size)
160 shift = g_hash_table_find_closest_shift (size);
161 shift = MAX (shift, HASH_TABLE_MIN_SHIFT);
163 g_hash_table_set_shift (hash_table, shift);
167 * g_hash_table_lookup_node:
168 * @hash_table: our #GHashTable
169 * @key: the key to lookup against
170 * @hash_return: optional key hash return location
171 * Return value: index of the described #GHashNode
173 * Performs a lookup in the hash table. Virtually all hash operations
174 * will use this function internally.
176 * This function first computes the hash value of the key using the
177 * user's hash function.
179 * If an entry in the table matching @key is found then this function
180 * returns the index of that entry in the table, and if not, the
181 * index of an empty node (never a tombstone).
184 g_hash_table_lookup_node (GHashTable *hash_table,
192 /* Empty buckets have hash_value set to 0, and for tombstones, it's 1.
193 * We need to make sure our hash value is not one of these. */
195 hash_value = (* hash_table->hash_func) (key);
196 if (G_UNLIKELY (hash_value <= 1))
199 node_index = hash_value % hash_table->mod;
200 node = &hash_table->nodes [node_index];
202 while (node->key_hash)
204 /* We first check if our full hash values
205 * are equal so we can avoid calling the full-blown
206 * key equality function in most cases.
209 if (node->key_hash == hash_value)
211 if (hash_table->key_equal_func)
213 if (hash_table->key_equal_func (node->key, key))
216 else if (node->key == key)
224 node_index &= hash_table->mask;
225 node = &hash_table->nodes [node_index];
232 * g_hash_table_lookup_node_for_insertion:
233 * @hash_table: our #GHashTable
234 * @key: the key to lookup against
235 * @hash_return: key hash return location
236 * Return value: index of the described #GHashNode
238 * Performs a lookup in the hash table, preserving extra information
239 * usually needed for insertion.
241 * This function first computes the hash value of the key using the
242 * user's hash function.
244 * If an entry in the table matching @key is found then this function
245 * returns the index of that entry in the table, and if not, the
246 * index of an unused node (empty or tombstone) where the key can be
249 * The computed hash value is returned in the variable pointed to
250 * by @hash_return. This is to save insertions from having to compute
251 * the hash record again for the new record.
254 g_hash_table_lookup_node_for_insertion (GHashTable *hash_table,
261 guint first_tombstone;
262 gboolean have_tombstone = FALSE;
265 /* Empty buckets have hash_value set to 0, and for tombstones, it's 1.
266 * We need to make sure our hash value is not one of these. */
268 hash_value = (* hash_table->hash_func) (key);
269 if (G_UNLIKELY (hash_value <= 1))
272 *hash_return = hash_value;
274 node_index = hash_value % hash_table->mod;
275 node = &hash_table->nodes [node_index];
277 while (node->key_hash)
279 /* We first check if our full hash values
280 * are equal so we can avoid calling the full-blown
281 * key equality function in most cases.
284 if (node->key_hash == hash_value)
286 if (hash_table->key_equal_func)
288 if (hash_table->key_equal_func (node->key, key))
291 else if (node->key == key)
296 else if (node->key_hash == 1 && !have_tombstone)
298 first_tombstone = node_index;
299 have_tombstone = TRUE;
304 node_index &= hash_table->mask;
305 node = &hash_table->nodes [node_index];
309 return first_tombstone;
315 * g_hash_table_remove_node:
316 * @hash_table: our #GHashTable
317 * @node: pointer to node to remove
318 * @notify: %TRUE if the destroy notify handlers are to be called
320 * Removes a node from the hash table and updates the node count.
321 * The node is replaced by a tombstone. No table resize is performed.
323 * If @notify is %TRUE then the destroy notify functions are called
324 * for the key and value of the hash node.
327 g_hash_table_remove_node (GHashTable *hash_table,
331 if (notify && hash_table->key_destroy_func)
332 hash_table->key_destroy_func (node->key);
334 if (notify && hash_table->value_destroy_func)
335 hash_table->value_destroy_func (node->value);
337 /* Erect tombstone */
344 hash_table->nnodes--;
348 * g_hash_table_remove_all_nodes:
349 * @hash_table: our #GHashTable
350 * @notify: %TRUE if the destroy notify handlers are to be called
352 * Removes all nodes from the table. Since this may be a precursor to
353 * freeing the table entirely, no resize is performed.
355 * If @notify is %TRUE then the destroy notify functions are called
356 * for the key and value of the hash node.
359 g_hash_table_remove_all_nodes (GHashTable *hash_table,
364 for (i = 0; i < hash_table->size; i++)
366 GHashNode *node = &hash_table->nodes [i];
368 if (node->key_hash > 1)
370 if (notify && hash_table->key_destroy_func)
371 hash_table->key_destroy_func (node->key);
373 if (notify && hash_table->value_destroy_func)
374 hash_table->value_destroy_func (node->value);
378 /* We need to set node->key_hash = 0 for all nodes - might as well be GC
379 * friendly and clear everything */
380 memset (hash_table->nodes, 0, hash_table->size * sizeof (GHashNode));
382 hash_table->nnodes = 0;
383 hash_table->noccupied = 0;
387 * g_hash_table_resize:
388 * @hash_table: our #GHashTable
390 * Resizes the hash table to the optimal size based on the number of
391 * nodes currently held. If you call this function then a resize will
392 * occur, even if one does not need to occur. Use
393 * g_hash_table_maybe_resize() instead.
395 * This function may "resize" the hash table to its current size, with
396 * the side effect of cleaning up tombstones and otherwise optimizing
397 * the probe sequences.
400 g_hash_table_resize (GHashTable *hash_table)
402 GHashNode *new_nodes;
406 old_size = hash_table->size;
407 g_hash_table_set_shift_from_size (hash_table, hash_table->nnodes * 2);
409 new_nodes = g_new0 (GHashNode, hash_table->size);
411 for (i = 0; i < old_size; i++)
413 GHashNode *node = &hash_table->nodes [i];
418 if (node->key_hash <= 1)
421 hash_val = node->key_hash % hash_table->mod;
422 new_node = &new_nodes [hash_val];
424 while (new_node->key_hash)
428 hash_val &= hash_table->mask;
429 new_node = &new_nodes [hash_val];
435 g_free (hash_table->nodes);
436 hash_table->nodes = new_nodes;
437 hash_table->noccupied = hash_table->nnodes;
441 * g_hash_table_maybe_resize:
442 * @hash_table: our #GHashTable
444 * Resizes the hash table, if needed.
446 * Essentially, calls g_hash_table_resize() if the table has strayed
447 * too far from its ideal size for its number of nodes.
450 g_hash_table_maybe_resize (GHashTable *hash_table)
452 gint noccupied = hash_table->noccupied;
453 gint size = hash_table->size;
455 if ((size > hash_table->nnodes * 4 && size > 1 << HASH_TABLE_MIN_SHIFT) ||
456 (size <= noccupied + (noccupied / 16)))
457 g_hash_table_resize (hash_table);
462 * @hash_func: a function to create a hash value from a key.
463 * Hash values are used to determine where keys are stored within the
464 * #GHashTable data structure. The g_direct_hash(), g_int_hash() and
465 * g_str_hash() functions are provided for some common types of keys.
466 * If hash_func is %NULL, g_direct_hash() is used.
467 * @key_equal_func: a function to check two keys for equality. This is
468 * used when looking up keys in the #GHashTable. The g_direct_equal(),
469 * g_int_equal() and g_str_equal() functions are provided for the most
470 * common types of keys. If @key_equal_func is %NULL, keys are compared
471 * directly in a similar fashion to g_direct_equal(), but without the
472 * overhead of a function call.
474 * Creates a new #GHashTable with a reference count of 1.
476 * Return value: a new #GHashTable.
479 g_hash_table_new (GHashFunc hash_func,
480 GEqualFunc key_equal_func)
482 return g_hash_table_new_full (hash_func, key_equal_func, NULL, NULL);
487 * g_hash_table_new_full:
488 * @hash_func: a function to create a hash value from a key.
489 * @key_equal_func: a function to check two keys for equality.
490 * @key_destroy_func: a function to free the memory allocated for the key
491 * used when removing the entry from the #GHashTable or %NULL if you
492 * don't want to supply such a function.
493 * @value_destroy_func: a function to free the memory allocated for the
494 * value used when removing the entry from the #GHashTable or %NULL if
495 * you don't want to supply such a function.
497 * Creates a new #GHashTable like g_hash_table_new() with a reference count
498 * of 1 and allows to specify functions to free the memory allocated for the
499 * key and value that get called when removing the entry from the #GHashTable.
501 * Return value: a new #GHashTable.
504 g_hash_table_new_full (GHashFunc hash_func,
505 GEqualFunc key_equal_func,
506 GDestroyNotify key_destroy_func,
507 GDestroyNotify value_destroy_func)
509 GHashTable *hash_table;
511 hash_table = g_slice_new (GHashTable);
512 g_hash_table_set_shift (hash_table, HASH_TABLE_MIN_SHIFT);
513 hash_table->nnodes = 0;
514 hash_table->noccupied = 0;
515 hash_table->hash_func = hash_func ? hash_func : g_direct_hash;
516 hash_table->key_equal_func = key_equal_func;
517 hash_table->ref_count = 1;
518 #ifndef G_DISABLE_ASSERT
519 hash_table->version = 0;
521 hash_table->key_destroy_func = key_destroy_func;
522 hash_table->value_destroy_func = value_destroy_func;
523 hash_table->nodes = g_new0 (GHashNode, hash_table->size);
529 * g_hash_table_iter_init:
530 * @iter: an uninitialized #GHashTableIter.
531 * @hash_table: a #GHashTable.
533 * Initializes a key/value pair iterator and associates it with
534 * @hash_table. Modifying the hash table after calling this function
535 * invalidates the returned iterator.
537 * GHashTableIter iter;
538 * gpointer key, value;
540 * g_hash_table_iter_init (&iter, hash_table);
541 * while (g_hash_table_iter_next (&iter, &key, &value))
543 * /* do something with key and value */
550 g_hash_table_iter_init (GHashTableIter *iter,
551 GHashTable *hash_table)
553 RealIter *ri = (RealIter *) iter;
555 g_return_if_fail (iter != NULL);
556 g_return_if_fail (hash_table != NULL);
558 ri->hash_table = hash_table;
560 #ifndef G_DISABLE_ASSERT
561 ri->version = hash_table->version;
566 * g_hash_table_iter_next:
567 * @iter: an initialized #GHashTableIter.
568 * @key: a location to store the key, or %NULL.
569 * @value: a location to store the value, or %NULL.
571 * Advances @iter and retrieves the key and/or value that are now
572 * pointed to as a result of this advancement. If %FALSE is returned,
573 * @key and @value are not set, and the iterator becomes invalid.
575 * Return value: %FALSE if the end of the #GHashTable has been reached.
580 g_hash_table_iter_next (GHashTableIter *iter,
584 RealIter *ri = (RealIter *) iter;
588 g_return_val_if_fail (iter != NULL, FALSE);
589 #ifndef G_DISABLE_ASSERT
590 g_return_val_if_fail (ri->version == ri->hash_table->version, FALSE);
592 g_return_val_if_fail (ri->position < ri->hash_table->size, FALSE);
594 position = ri->position;
599 if (position >= ri->hash_table->size)
601 ri->position = position;
605 node = &ri->hash_table->nodes [position];
607 while (node->key_hash <= 1);
612 *value = node->value;
614 ri->position = position;
619 * g_hash_table_iter_get_hash_table:
620 * @iter: an initialized #GHashTableIter.
622 * Returns the #GHashTable associated with @iter.
624 * Return value: the #GHashTable associated with @iter.
629 g_hash_table_iter_get_hash_table (GHashTableIter *iter)
631 g_return_val_if_fail (iter != NULL, NULL);
633 return ((RealIter *) iter)->hash_table;
637 iter_remove_or_steal (RealIter *ri, gboolean notify)
639 g_return_if_fail (ri != NULL);
640 #ifndef G_DISABLE_ASSERT
641 g_return_if_fail (ri->version == ri->hash_table->version);
643 g_return_if_fail (ri->position >= 0);
644 g_return_if_fail (ri->position < ri->hash_table->size);
646 g_hash_table_remove_node (ri->hash_table, &ri->hash_table->nodes [ri->position], notify);
648 #ifndef G_DISABLE_ASSERT
650 ri->hash_table->version++;
655 * g_hash_table_iter_remove():
656 * @iter: an initialized #GHashTableIter.
658 * Removes the key/value pair currently pointed to by the iterator
659 * from its associated #GHashTable. Can only be called after
660 * g_hash_table_iter_next() returned %TRUE, and cannot be called more
661 * than once for the same key/value pair.
663 * If the #GHashTable was created using g_hash_table_new_full(), the
664 * key and value are freed using the supplied destroy functions, otherwise
665 * you have to make sure that any dynamically allocated values are freed
671 g_hash_table_iter_remove (GHashTableIter *iter)
673 iter_remove_or_steal ((RealIter *) iter, TRUE);
677 * g_hash_table_iter_steal():
678 * @iter: an initialized #GHashTableIter.
680 * Removes the key/value pair currently pointed to by the iterator
681 * from its associated #GHashTable, without calling the key and value
682 * destroy functions. Can only be called after
683 * g_hash_table_iter_next() returned %TRUE, and cannot be called more
684 * than once for the same key/value pair.
689 g_hash_table_iter_steal (GHashTableIter *iter)
691 iter_remove_or_steal ((RealIter *) iter, FALSE);
697 * @hash_table: a valid #GHashTable.
699 * Atomically increments the reference count of @hash_table by one.
700 * This function is MT-safe and may be called from any thread.
702 * Return value: the passed in #GHashTable.
707 g_hash_table_ref (GHashTable *hash_table)
709 g_return_val_if_fail (hash_table != NULL, NULL);
710 g_return_val_if_fail (hash_table->ref_count > 0, hash_table);
712 g_atomic_int_add (&hash_table->ref_count, 1);
717 * g_hash_table_unref:
718 * @hash_table: a valid #GHashTable.
720 * Atomically decrements the reference count of @hash_table by one.
721 * If the reference count drops to 0, all keys and values will be
722 * destroyed, and all memory allocated by the hash table is released.
723 * This function is MT-safe and may be called from any thread.
728 g_hash_table_unref (GHashTable *hash_table)
730 g_return_if_fail (hash_table != NULL);
731 g_return_if_fail (hash_table->ref_count > 0);
733 if (g_atomic_int_exchange_and_add (&hash_table->ref_count, -1) - 1 == 0)
735 g_hash_table_remove_all_nodes (hash_table, TRUE);
736 g_free (hash_table->nodes);
737 g_slice_free (GHashTable, hash_table);
742 * g_hash_table_destroy:
743 * @hash_table: a #GHashTable.
745 * Destroys all keys and values in the #GHashTable and decrements its
746 * reference count by 1. If keys and/or values are dynamically allocated,
747 * you should either free them first or create the #GHashTable with destroy
748 * notifiers using g_hash_table_new_full(). In the latter case the destroy
749 * functions you supplied will be called on all keys and values during the
753 g_hash_table_destroy (GHashTable *hash_table)
755 g_return_if_fail (hash_table != NULL);
756 g_return_if_fail (hash_table->ref_count > 0);
758 g_hash_table_remove_all (hash_table);
759 g_hash_table_unref (hash_table);
763 * g_hash_table_lookup:
764 * @hash_table: a #GHashTable.
765 * @key: the key to look up.
767 * Looks up a key in a #GHashTable. Note that this function cannot
768 * distinguish between a key that is not present and one which is present
769 * and has the value %NULL. If you need this distinction, use
770 * g_hash_table_lookup_extended().
772 * Return value: the associated value, or %NULL if the key is not found.
775 g_hash_table_lookup (GHashTable *hash_table,
781 g_return_val_if_fail (hash_table != NULL, NULL);
783 node_index = g_hash_table_lookup_node (hash_table, key);
784 node = &hash_table->nodes [node_index];
786 return node->key_hash ? node->value : NULL;
790 * g_hash_table_lookup_extended:
791 * @hash_table: a #GHashTable.
792 * @lookup_key: the key to look up.
793 * @orig_key: returns the original key.
794 * @value: returns the value associated with the key.
796 * Looks up a key in the #GHashTable, returning the original key and the
797 * associated value and a #gboolean which is %TRUE if the key was found. This
798 * is useful if you need to free the memory allocated for the original key,
799 * for example before calling g_hash_table_remove().
801 * Return value: %TRUE if the key was found in the #GHashTable.
804 g_hash_table_lookup_extended (GHashTable *hash_table,
805 gconstpointer lookup_key,
812 g_return_val_if_fail (hash_table != NULL, FALSE);
814 node_index = g_hash_table_lookup_node (hash_table, lookup_key);
815 node = &hash_table->nodes [node_index];
821 *orig_key = node->key;
824 *value = node->value;
830 * g_hash_table_insert_internal:
831 * @hash_table: our #GHashTable
832 * @key: the key to insert
833 * @value: the value to insert
834 * @keep_new_key: if %TRUE and this key already exists in the table
835 * then call the destroy notify function on the old key. If %FALSE
836 * then call the destroy notify function on the new key.
838 * Implements the common logic for the g_hash_table_insert() and
839 * g_hash_table_replace() functions.
841 * Do a lookup of @key. If it is found, replace it with the new
842 * @value (and perhaps the new @key). If it is not found, create a
846 g_hash_table_insert_internal (GHashTable *hash_table,
849 gboolean keep_new_key)
856 g_return_if_fail (hash_table != NULL);
857 g_return_if_fail (hash_table->ref_count > 0);
859 node_index = g_hash_table_lookup_node_for_insertion (hash_table, key, &key_hash);
860 node = &hash_table->nodes [node_index];
862 old_hash = node->key_hash;
868 if (hash_table->key_destroy_func)
869 hash_table->key_destroy_func (node->key);
874 if (hash_table->key_destroy_func)
875 hash_table->key_destroy_func (key);
878 if (hash_table->value_destroy_func)
879 hash_table->value_destroy_func (node->value);
887 node->key_hash = key_hash;
889 hash_table->nnodes++;
893 /* We replaced an empty node, and not a tombstone */
894 hash_table->noccupied++;
895 g_hash_table_maybe_resize (hash_table);
898 #ifndef G_DISABLE_ASSERT
899 hash_table->version++;
905 * g_hash_table_insert:
906 * @hash_table: a #GHashTable.
907 * @key: a key to insert.
908 * @value: the value to associate with the key.
910 * Inserts a new key and value into a #GHashTable.
912 * If the key already exists in the #GHashTable its current value is replaced
913 * with the new value. If you supplied a @value_destroy_func when creating the
914 * #GHashTable, the old value is freed using that function. If you supplied
915 * a @key_destroy_func when creating the #GHashTable, the passed key is freed
916 * using that function.
919 g_hash_table_insert (GHashTable *hash_table,
923 g_hash_table_insert_internal (hash_table, key, value, FALSE);
927 * g_hash_table_replace:
928 * @hash_table: a #GHashTable.
929 * @key: a key to insert.
930 * @value: the value to associate with the key.
932 * Inserts a new key and value into a #GHashTable similar to
933 * g_hash_table_insert(). The difference is that if the key already exists
934 * in the #GHashTable, it gets replaced by the new key. If you supplied a
935 * @value_destroy_func when creating the #GHashTable, the old value is freed
936 * using that function. If you supplied a @key_destroy_func when creating the
937 * #GHashTable, the old key is freed using that function.
940 g_hash_table_replace (GHashTable *hash_table,
944 g_hash_table_insert_internal (hash_table, key, value, TRUE);
948 * g_hash_table_remove_internal:
949 * @hash_table: our #GHashTable
950 * @key: the key to remove
951 * @notify: %TRUE if the destroy notify handlers are to be called
952 * Return value: %TRUE if a node was found and removed, else %FALSE
954 * Implements the common logic for the g_hash_table_remove() and
955 * g_hash_table_steal() functions.
957 * Do a lookup of @key and remove it if it is found, calling the
958 * destroy notify handlers only if @notify is %TRUE.
961 g_hash_table_remove_internal (GHashTable *hash_table,
968 g_return_val_if_fail (hash_table != NULL, FALSE);
970 node_index = g_hash_table_lookup_node (hash_table, key);
971 node = &hash_table->nodes [node_index];
973 /* g_hash_table_lookup_node() never returns a tombstone, so this is safe */
977 g_hash_table_remove_node (hash_table, node, notify);
978 g_hash_table_maybe_resize (hash_table);
980 #ifndef G_DISABLE_ASSERT
981 hash_table->version++;
988 * g_hash_table_remove:
989 * @hash_table: a #GHashTable.
990 * @key: the key to remove.
992 * Removes a key and its associated value from a #GHashTable.
994 * If the #GHashTable was created using g_hash_table_new_full(), the
995 * key and value are freed using the supplied destroy functions, otherwise
996 * you have to make sure that any dynamically allocated values are freed
999 * Return value: %TRUE if the key was found and removed from the #GHashTable.
1002 g_hash_table_remove (GHashTable *hash_table,
1005 return g_hash_table_remove_internal (hash_table, key, TRUE);
1009 * g_hash_table_steal:
1010 * @hash_table: a #GHashTable.
1011 * @key: the key to remove.
1013 * Removes a key and its associated value from a #GHashTable without
1014 * calling the key and value destroy functions.
1016 * Return value: %TRUE if the key was found and removed from the #GHashTable.
1019 g_hash_table_steal (GHashTable *hash_table,
1022 return g_hash_table_remove_internal (hash_table, key, FALSE);
1026 * g_hash_table_remove_all:
1027 * @hash_table: a #GHashTable
1029 * Removes all keys and their associated values from a #GHashTable.
1031 * If the #GHashTable was created using g_hash_table_new_full(), the keys
1032 * and values are freed using the supplied destroy functions, otherwise you
1033 * have to make sure that any dynamically allocated values are freed
1039 g_hash_table_remove_all (GHashTable *hash_table)
1041 g_return_if_fail (hash_table != NULL);
1043 #ifndef G_DISABLE_ASSERT
1044 if (hash_table->nnodes != 0)
1045 hash_table->version++;
1048 g_hash_table_remove_all_nodes (hash_table, TRUE);
1049 g_hash_table_maybe_resize (hash_table);
1053 * g_hash_table_steal_all:
1054 * @hash_table: a #GHashTable.
1056 * Removes all keys and their associated values from a #GHashTable
1057 * without calling the key and value destroy functions.
1062 g_hash_table_steal_all (GHashTable *hash_table)
1064 g_return_if_fail (hash_table != NULL);
1066 #ifndef G_DISABLE_ASSERT
1067 if (hash_table->nnodes != 0)
1068 hash_table->version++;
1071 g_hash_table_remove_all_nodes (hash_table, FALSE);
1072 g_hash_table_maybe_resize (hash_table);
1076 * g_hash_table_foreach_remove_or_steal:
1077 * @hash_table: our #GHashTable
1078 * @func: the user's callback function
1079 * @user_data: data for @func
1080 * @notify: %TRUE if the destroy notify handlers are to be called
1082 * Implements the common logic for g_hash_table_foreach_remove() and
1083 * g_hash_table_foreach_steal().
1085 * Iterates over every node in the table, calling @func with the key
1086 * and value of the node (and @user_data). If @func returns %TRUE the
1087 * node is removed from the table.
1089 * If @notify is true then the destroy notify handlers will be called
1090 * for each removed node.
1093 g_hash_table_foreach_remove_or_steal (GHashTable *hash_table,
1101 for (i = 0; i < hash_table->size; i++)
1103 GHashNode *node = &hash_table->nodes [i];
1105 if (node->key_hash > 1 && (* func) (node->key, node->value, user_data))
1107 g_hash_table_remove_node (hash_table, node, notify);
1112 g_hash_table_maybe_resize (hash_table);
1114 #ifndef G_DISABLE_ASSERT
1116 hash_table->version++;
1123 * g_hash_table_foreach_remove:
1124 * @hash_table: a #GHashTable.
1125 * @func: the function to call for each key/value pair.
1126 * @user_data: user data to pass to the function.
1128 * Calls the given function for each key/value pair in the #GHashTable.
1129 * If the function returns %TRUE, then the key/value pair is removed from the
1130 * #GHashTable. If you supplied key or value destroy functions when creating
1131 * the #GHashTable, they are used to free the memory allocated for the removed
1134 * See #GHashTableIterator for an alternative way to loop over the
1135 * key/value pairs in the hash table.
1137 * Return value: the number of key/value pairs removed.
1140 g_hash_table_foreach_remove (GHashTable *hash_table,
1144 g_return_val_if_fail (hash_table != NULL, 0);
1145 g_return_val_if_fail (func != NULL, 0);
1147 return g_hash_table_foreach_remove_or_steal (hash_table, func, user_data, TRUE);
1151 * g_hash_table_foreach_steal:
1152 * @hash_table: a #GHashTable.
1153 * @func: the function to call for each key/value pair.
1154 * @user_data: user data to pass to the function.
1156 * Calls the given function for each key/value pair in the #GHashTable.
1157 * If the function returns %TRUE, then the key/value pair is removed from the
1158 * #GHashTable, but no key or value destroy functions are called.
1160 * See #GHashTableIterator for an alternative way to loop over the
1161 * key/value pairs in the hash table.
1163 * Return value: the number of key/value pairs removed.
1166 g_hash_table_foreach_steal (GHashTable *hash_table,
1170 g_return_val_if_fail (hash_table != NULL, 0);
1171 g_return_val_if_fail (func != NULL, 0);
1173 return g_hash_table_foreach_remove_or_steal (hash_table, func, user_data, FALSE);
1177 * g_hash_table_foreach:
1178 * @hash_table: a #GHashTable.
1179 * @func: the function to call for each key/value pair.
1180 * @user_data: user data to pass to the function.
1182 * Calls the given function for each of the key/value pairs in the
1183 * #GHashTable. The function is passed the key and value of each
1184 * pair, and the given @user_data parameter. The hash table may not
1185 * be modified while iterating over it (you can't add/remove
1186 * items). To remove all items matching a predicate, use
1187 * g_hash_table_foreach_remove().
1189 * See g_hash_table_find() for performance caveats for linear
1190 * order searches in contrast to g_hash_table_lookup().
1193 g_hash_table_foreach (GHashTable *hash_table,
1199 g_return_if_fail (hash_table != NULL);
1200 g_return_if_fail (func != NULL);
1202 for (i = 0; i < hash_table->size; i++)
1204 GHashNode *node = &hash_table->nodes [i];
1206 if (node->key_hash > 1)
1207 (* func) (node->key, node->value, user_data);
1212 * g_hash_table_find:
1213 * @hash_table: a #GHashTable.
1214 * @predicate: function to test the key/value pairs for a certain property.
1215 * @user_data: user data to pass to the function.
1217 * Calls the given function for key/value pairs in the #GHashTable until
1218 * @predicate returns %TRUE. The function is passed the key and value of
1219 * each pair, and the given @user_data parameter. The hash table may not
1220 * be modified while iterating over it (you can't add/remove items).
1222 * Note, that hash tables are really only optimized for forward lookups,
1223 * i.e. g_hash_table_lookup().
1224 * So code that frequently issues g_hash_table_find() or
1225 * g_hash_table_foreach() (e.g. in the order of once per every entry in a
1226 * hash table) should probably be reworked to use additional or different
1227 * data structures for reverse lookups (keep in mind that an O(n) find/foreach
1228 * operation issued for all n values in a hash table ends up needing O(n*n)
1231 * Return value: The value of the first key/value pair is returned, for which
1232 * func evaluates to %TRUE. If no pair with the requested property is found,
1233 * %NULL is returned.
1238 g_hash_table_find (GHashTable *hash_table,
1244 g_return_val_if_fail (hash_table != NULL, NULL);
1245 g_return_val_if_fail (predicate != NULL, NULL);
1247 for (i = 0; i < hash_table->size; i++)
1249 GHashNode *node = &hash_table->nodes [i];
1251 if (node->key_hash > 1 && predicate (node->key, node->value, user_data))
1259 * g_hash_table_size:
1260 * @hash_table: a #GHashTable.
1262 * Returns the number of elements contained in the #GHashTable.
1264 * Return value: the number of key/value pairs in the #GHashTable.
1267 g_hash_table_size (GHashTable *hash_table)
1269 g_return_val_if_fail (hash_table != NULL, 0);
1271 return hash_table->nnodes;
1275 * g_hash_table_get_keys:
1276 * @hash_table: a #GHashTable
1278 * Retrieves every key inside @hash_table. The returned data is valid
1279 * until @hash_table is modified.
1281 * Return value: a #GList containing all the keys inside the hash
1282 * table. The content of the list is owned by the hash table and
1283 * should not be modified or freed. Use g_list_free() when done
1289 g_hash_table_get_keys (GHashTable *hash_table)
1294 g_return_val_if_fail (hash_table != NULL, NULL);
1297 for (i = 0; i < hash_table->size; i++)
1299 GHashNode *node = &hash_table->nodes [i];
1301 if (node->key_hash > 1)
1302 retval = g_list_prepend (retval, node->key);
1309 * g_hash_table_get_values:
1310 * @hash_table: a #GHashTable
1312 * Retrieves every value inside @hash_table. The returned data is
1313 * valid until @hash_table is modified.
1315 * Return value: a #GList containing all the values inside the hash
1316 * table. The content of the list is owned by the hash table and
1317 * should not be modified or freed. Use g_list_free() when done
1323 g_hash_table_get_values (GHashTable *hash_table)
1328 g_return_val_if_fail (hash_table != NULL, NULL);
1331 for (i = 0; i < hash_table->size; i++)
1333 GHashNode *node = &hash_table->nodes [i];
1335 if (node->key_hash > 1)
1336 retval = g_list_prepend (retval, node->value);
1342 #define __G_HASH_C__
1343 #include "galiasdef.c"