Rename exporter APIs
[glib.git] / glib / ghash.c
blobace1c372bdef027ed98d3cfce123534743c98e9e
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/.
28 * MT safe
31 #include "config.h"
33 #include <string.h> /* memset */
35 #include "ghash.h"
37 #include "gstrfuncs.h"
38 #include "gatomic.h"
39 #include "gtestutils.h"
40 #include "gslice.h"
43 /**
44 * SECTION:hash_tables
45 * @title: Hash Tables
46 * @short_description: associations between keys and values so that
47 * given a key the value can be found quickly
49 * A #GHashTable provides associations between keys and values which is
50 * optimized so that given a key, the associated value can be found
51 * very quickly.
53 * Note that neither keys nor values are copied when inserted into the
54 * #GHashTable, so they must exist for the lifetime of the #GHashTable.
55 * This means that the use of static strings is OK, but temporary
56 * strings (i.e. those created in buffers and those returned by GTK+
57 * widgets) should be copied with g_strdup() before being inserted.
59 * If keys or values are dynamically allocated, you must be careful to
60 * ensure that they are freed when they are removed from the
61 * #GHashTable, and also when they are overwritten by new insertions
62 * into the #GHashTable. It is also not advisable to mix static strings
63 * and dynamically-allocated strings in a #GHashTable, because it then
64 * becomes difficult to determine whether the string should be freed.
66 * To create a #GHashTable, use g_hash_table_new().
68 * To insert a key and value into a #GHashTable, use
69 * g_hash_table_insert().
71 * To lookup a value corresponding to a given key, use
72 * g_hash_table_lookup() and g_hash_table_lookup_extended().
74 * g_hash_table_lookup_extended() can also be used to simply
75 * check if a key is present in the hash table.
77 * To remove a key and value, use g_hash_table_remove().
79 * To call a function for each key and value pair use
80 * g_hash_table_foreach() or use a iterator to iterate over the
81 * key/value pairs in the hash table, see #GHashTableIter.
83 * To destroy a #GHashTable use g_hash_table_destroy().
85 * <example>
86 * <title>Using a GHashTable as a set</title>
87 * <para>
88 * A common use-case for hash tables is to store information about
89 * a set of keys, without associating any particular value with each
90 * key. GHashTable optimizes one way of doing so: If you store only
91 * key-value pairs where key == value, then GHashTable does not
92 * allocate memory to store the values, which can be a considerable
93 * space saving, if your set is large.
94 * </para>
95 * <programlisting>
96 * GHashTable *
97 * set_new (GHashFunc hash_func,
98 * GEqualFunc equal_func,
99 * GDestroyNotify destroy)
101 * return g_hash_table_new_full (hash_func, equal_func, destroy, NULL);
104 * void
105 * set_insert (GHashTable *set,
106 * gpointer element)
108 * g_hash_table_insert (set, element, element);
111 * gboolean
112 * set_contains (GHashTable *set,
113 * gpointer element)
115 * return g_hash_table_lookup_extended (set, element, NULL, NULL);
118 * gboolean
119 * set_remove (GHashTable *set,
120 * gpointer element)
122 * return g_hash_table_remove (set, element);
124 * </programlisting>
125 * </example>
129 * GHashTable:
131 * The #GHashTable struct is an opaque data structure to represent a
132 * <link linkend="glib-Hash-Tables">Hash Table</link>. It should only be
133 * accessed via the following functions.
137 * GHashFunc:
138 * @key: a key
140 * Specifies the type of the hash function which is passed to
141 * g_hash_table_new() when a #GHashTable is created.
143 * The function is passed a key and should return a #guint hash value.
144 * The functions g_direct_hash(), g_int_hash() and g_str_hash() provide
145 * hash functions which can be used when the key is a #gpointer, #gint*,
146 * and #gchar* respectively.
148 * g_direct_hash() is also the appropriate hash function for keys
149 * of the form <literal>GINT_TO_POINTER (n)</literal> (or similar macros).
151 * <!-- FIXME: Need more here. --> The hash values should be evenly
152 * distributed over a fairly large range? The modulus is taken with the
153 * hash table size (a prime number) to find the 'bucket' to place each
154 * key into. The function should also be very fast, since it is called
155 * for each key lookup.
157 * Returns: the hash value corresponding to the key
161 * GHFunc:
162 * @key: a key
163 * @value: the value corresponding to the key
164 * @user_data: user data passed to g_hash_table_foreach()
166 * Specifies the type of the function passed to g_hash_table_foreach().
167 * It is called with each key/value pair, together with the @user_data
168 * parameter which is passed to g_hash_table_foreach().
172 * GHRFunc:
173 * @key: a key
174 * @value: the value associated with the key
175 * @user_data: user data passed to g_hash_table_remove()
177 * Specifies the type of the function passed to
178 * g_hash_table_foreach_remove(). It is called with each key/value
179 * pair, together with the @user_data parameter passed to
180 * g_hash_table_foreach_remove(). It should return %TRUE if the
181 * key/value pair should be removed from the #GHashTable.
183 * Returns: %TRUE if the key/value pair should be removed from the
184 * #GHashTable
188 * GEqualFunc:
189 * @a: a value
190 * @b: a value to compare with
192 * Specifies the type of a function used to test two values for
193 * equality. The function should return %TRUE if both values are equal
194 * and %FALSE otherwise.
196 * Returns: %TRUE if @a = @b; %FALSE otherwise
200 * GHashTableIter:
202 * A GHashTableIter structure represents an iterator that can be used
203 * to iterate over the elements of a #GHashTable. GHashTableIter
204 * structures are typically allocated on the stack and then initialized
205 * with g_hash_table_iter_init().
209 * g_hash_table_freeze:
210 * @hash_table: a #GHashTable
212 * This function is deprecated and will be removed in the next major
213 * release of GLib. It does nothing.
217 * g_hash_table_thaw:
218 * @hash_table: a #GHashTable
220 * This function is deprecated and will be removed in the next major
221 * release of GLib. It does nothing.
224 #define HASH_TABLE_MIN_SHIFT 3 /* 1 << 3 == 8 buckets */
226 #define UNUSED_HASH_VALUE 0
227 #define TOMBSTONE_HASH_VALUE 1
228 #define HASH_IS_UNUSED(h_) ((h_) == UNUSED_HASH_VALUE)
229 #define HASH_IS_TOMBSTONE(h_) ((h_) == TOMBSTONE_HASH_VALUE)
230 #define HASH_IS_REAL(h_) ((h_) >= 2)
232 struct _GHashTable
234 gint size;
235 gint mod;
236 guint mask;
237 gint nnodes;
238 gint noccupied; /* nnodes + tombstones */
240 gpointer *keys;
241 guint *hashes;
242 gpointer *values;
244 GHashFunc hash_func;
245 GEqualFunc key_equal_func;
246 gint ref_count;
247 #ifndef G_DISABLE_ASSERT
249 * Tracks the structure of the hash table, not its contents: is only
250 * incremented when a node is added or removed (is not incremented
251 * when the key or data of a node is modified).
253 int version;
254 #endif
255 GDestroyNotify key_destroy_func;
256 GDestroyNotify value_destroy_func;
259 typedef struct
261 GHashTable *hash_table;
262 gpointer dummy1;
263 gpointer dummy2;
264 int position;
265 gboolean dummy3;
266 int version;
267 } RealIter;
269 /* Each table size has an associated prime modulo (the first prime
270 * lower than the table size) used to find the initial bucket. Probing
271 * then works modulo 2^n. The prime modulo is necessary to get a
272 * good distribution with poor hash functions.
274 static const gint prime_mod [] =
276 1, /* For 1 << 0 */
283 127,
284 251,
285 509,
286 1021,
287 2039,
288 4093,
289 8191,
290 16381,
291 32749,
292 65521, /* For 1 << 16 */
293 131071,
294 262139,
295 524287,
296 1048573,
297 2097143,
298 4194301,
299 8388593,
300 16777213,
301 33554393,
302 67108859,
303 134217689,
304 268435399,
305 536870909,
306 1073741789,
307 2147483647 /* For 1 << 31 */
310 static void
311 g_hash_table_set_shift (GHashTable *hash_table, gint shift)
313 gint i;
314 guint mask = 0;
316 hash_table->size = 1 << shift;
317 hash_table->mod = prime_mod [shift];
319 for (i = 0; i < shift; i++)
321 mask <<= 1;
322 mask |= 1;
325 hash_table->mask = mask;
328 static gint
329 g_hash_table_find_closest_shift (gint n)
331 gint i;
333 for (i = 0; n; i++)
334 n >>= 1;
336 return i;
339 static void
340 g_hash_table_set_shift_from_size (GHashTable *hash_table, gint size)
342 gint shift;
344 shift = g_hash_table_find_closest_shift (size);
345 shift = MAX (shift, HASH_TABLE_MIN_SHIFT);
347 g_hash_table_set_shift (hash_table, shift);
351 * g_hash_table_lookup_node:
352 * @hash_table: our #GHashTable
353 * @key: the key to lookup against
354 * @hash_return: key hash return location
356 * Performs a lookup in the hash table, preserving extra information
357 * usually needed for insertion.
359 * This function first computes the hash value of the key using the
360 * user's hash function.
362 * If an entry in the table matching @key is found then this function
363 * returns the index of that entry in the table, and if not, the
364 * index of an unused node (empty or tombstone) where the key can be
365 * inserted.
367 * The computed hash value is returned in the variable pointed to
368 * by @hash_return. This is to save insertions from having to compute
369 * the hash record again for the new record.
371 * Returns: index of the described node
373 static inline guint
374 g_hash_table_lookup_node (GHashTable *hash_table,
375 gconstpointer key,
376 guint *hash_return)
378 guint node_index;
379 guint node_hash;
380 guint hash_value;
381 guint first_tombstone = 0;
382 gboolean have_tombstone = FALSE;
383 guint step = 0;
385 hash_value = hash_table->hash_func (key);
386 if (G_UNLIKELY (!HASH_IS_REAL (hash_value)))
387 hash_value = 2;
389 *hash_return = hash_value;
391 node_index = hash_value % hash_table->mod;
392 node_hash = hash_table->hashes[node_index];
394 while (!HASH_IS_UNUSED (node_hash))
396 /* We first check if our full hash values
397 * are equal so we can avoid calling the full-blown
398 * key equality function in most cases.
400 if (node_hash == hash_value)
402 gpointer node_key = hash_table->keys[node_index];
404 if (hash_table->key_equal_func)
406 if (hash_table->key_equal_func (node_key, key))
407 return node_index;
409 else if (node_key == key)
411 return node_index;
414 else if (HASH_IS_TOMBSTONE (node_hash) && !have_tombstone)
416 first_tombstone = node_index;
417 have_tombstone = TRUE;
420 step++;
421 node_index += step;
422 node_index &= hash_table->mask;
423 node_hash = hash_table->hashes[node_index];
426 if (have_tombstone)
427 return first_tombstone;
429 return node_index;
433 * g_hash_table_remove_node:
434 * @hash_table: our #GHashTable
435 * @node: pointer to node to remove
436 * @notify: %TRUE if the destroy notify handlers are to be called
438 * Removes a node from the hash table and updates the node count.
439 * The node is replaced by a tombstone. No table resize is performed.
441 * If @notify is %TRUE then the destroy notify functions are called
442 * for the key and value of the hash node.
444 static void
445 g_hash_table_remove_node (GHashTable *hash_table,
446 gint i,
447 gboolean notify)
449 gpointer key;
450 gpointer value;
452 key = hash_table->keys[i];
453 value = hash_table->values[i];
455 /* Erect tombstone */
456 hash_table->hashes[i] = TOMBSTONE_HASH_VALUE;
458 /* Be GC friendly */
459 hash_table->keys[i] = NULL;
460 hash_table->values[i] = NULL;
462 hash_table->nnodes--;
464 if (notify && hash_table->key_destroy_func)
465 hash_table->key_destroy_func (key);
467 if (notify && hash_table->value_destroy_func)
468 hash_table->value_destroy_func (value);
473 * g_hash_table_remove_all_nodes:
474 * @hash_table: our #GHashTable
475 * @notify: %TRUE if the destroy notify handlers are to be called
477 * Removes all nodes from the table. Since this may be a precursor to
478 * freeing the table entirely, no resize is performed.
480 * If @notify is %TRUE then the destroy notify functions are called
481 * for the key and value of the hash node.
483 static void
484 g_hash_table_remove_all_nodes (GHashTable *hash_table,
485 gboolean notify)
487 int i;
488 gpointer key;
489 gpointer value;
491 hash_table->nnodes = 0;
492 hash_table->noccupied = 0;
494 if (!notify ||
495 (hash_table->key_destroy_func == NULL &&
496 hash_table->value_destroy_func == NULL))
498 memset (hash_table->hashes, 0, hash_table->size * sizeof (guint));
499 memset (hash_table->keys, 0, hash_table->size * sizeof (gpointer));
500 memset (hash_table->values, 0, hash_table->size * sizeof (gpointer));
502 return;
505 for (i = 0; i < hash_table->size; i++)
507 if (HASH_IS_REAL (hash_table->hashes[i]))
509 key = hash_table->keys[i];
510 value = hash_table->values[i];
512 hash_table->hashes[i] = UNUSED_HASH_VALUE;
513 hash_table->keys[i] = NULL;
514 hash_table->values[i] = NULL;
516 if (hash_table->key_destroy_func != NULL)
517 hash_table->key_destroy_func (key);
519 if (hash_table->value_destroy_func != NULL)
520 hash_table->value_destroy_func (value);
522 else if (HASH_IS_TOMBSTONE (hash_table->hashes[i]))
524 hash_table->hashes[i] = UNUSED_HASH_VALUE;
530 * g_hash_table_resize:
531 * @hash_table: our #GHashTable
533 * Resizes the hash table to the optimal size based on the number of
534 * nodes currently held. If you call this function then a resize will
535 * occur, even if one does not need to occur.
536 * Use g_hash_table_maybe_resize() instead.
538 * This function may "resize" the hash table to its current size, with
539 * the side effect of cleaning up tombstones and otherwise optimizing
540 * the probe sequences.
542 static void
543 g_hash_table_resize (GHashTable *hash_table)
545 gpointer *new_keys;
546 gpointer *new_values;
547 guint *new_hashes;
548 gint old_size;
549 gint i;
551 old_size = hash_table->size;
552 g_hash_table_set_shift_from_size (hash_table, hash_table->nnodes * 2);
554 new_keys = g_new0 (gpointer, hash_table->size);
555 if (hash_table->keys == hash_table->values)
556 new_values = new_keys;
557 else
558 new_values = g_new0 (gpointer, hash_table->size);
559 new_hashes = g_new0 (guint, hash_table->size);
561 for (i = 0; i < old_size; i++)
563 guint node_hash = hash_table->hashes[i];
564 guint hash_val;
565 guint step = 0;
567 if (!HASH_IS_REAL (node_hash))
568 continue;
570 hash_val = node_hash % hash_table->mod;
572 while (!HASH_IS_UNUSED (new_hashes[hash_val]))
574 step++;
575 hash_val += step;
576 hash_val &= hash_table->mask;
579 new_hashes[hash_val] = hash_table->hashes[i];
580 new_keys[hash_val] = hash_table->keys[i];
581 new_values[hash_val] = hash_table->values[i];
584 if (hash_table->keys != hash_table->values)
585 g_free (hash_table->values);
587 g_free (hash_table->keys);
588 g_free (hash_table->hashes);
590 hash_table->keys = new_keys;
591 hash_table->values = new_values;
592 hash_table->hashes = new_hashes;
594 hash_table->noccupied = hash_table->nnodes;
598 * g_hash_table_maybe_resize:
599 * @hash_table: our #GHashTable
601 * Resizes the hash table, if needed.
603 * Essentially, calls g_hash_table_resize() if the table has strayed
604 * too far from its ideal size for its number of nodes.
606 static inline void
607 g_hash_table_maybe_resize (GHashTable *hash_table)
609 gint noccupied = hash_table->noccupied;
610 gint size = hash_table->size;
612 if ((size > hash_table->nnodes * 4 && size > 1 << HASH_TABLE_MIN_SHIFT) ||
613 (size <= noccupied + (noccupied / 16)))
614 g_hash_table_resize (hash_table);
618 * g_hash_table_new:
619 * @hash_func: a function to create a hash value from a key
620 * @key_equal_func: a function to check two keys for equality
622 * Creates a new #GHashTable with a reference count of 1.
624 * Hash values returned by @hash_func are used to determine where keys
625 * are stored within the #GHashTable data structure. The g_direct_hash(),
626 * g_int_hash(), g_int64_hash(), g_double_hash() and g_str_hash()
627 * functions are provided for some common types of keys.
628 * If @hash_func is %NULL, g_direct_hash() is used.
630 * @key_equal_func is used when looking up keys in the #GHashTable.
631 * The g_direct_equal(), g_int_equal(), g_int64_equal(), g_double_equal()
632 * and g_str_equal() functions are provided for the most common types
633 * of keys. If @key_equal_func is %NULL, keys are compared directly in
634 * a similar fashion to g_direct_equal(), but without the overhead of
635 * a function call.
637 * Return value: a new #GHashTable
639 GHashTable *
640 g_hash_table_new (GHashFunc hash_func,
641 GEqualFunc key_equal_func)
643 return g_hash_table_new_full (hash_func, key_equal_func, NULL, NULL);
648 * g_hash_table_new_full:
649 * @hash_func: a function to create a hash value from a key
650 * @key_equal_func: a function to check two keys for equality
651 * @key_destroy_func: a function to free the memory allocated for the key
652 * used when removing the entry from the #GHashTable, or %NULL
653 * if you don't want to supply such a function.
654 * @value_destroy_func: a function to free the memory allocated for the
655 * value used when removing the entry from the #GHashTable, or %NULL
656 * if you don't want to supply such a function.
658 * Creates a new #GHashTable like g_hash_table_new() with a reference
659 * count of 1 and allows to specify functions to free the memory
660 * allocated for the key and value that get called when removing the
661 * entry from the #GHashTable.
663 * Return value: a new #GHashTable
665 GHashTable *
666 g_hash_table_new_full (GHashFunc hash_func,
667 GEqualFunc key_equal_func,
668 GDestroyNotify key_destroy_func,
669 GDestroyNotify value_destroy_func)
671 GHashTable *hash_table;
673 hash_table = g_slice_new (GHashTable);
674 g_hash_table_set_shift (hash_table, HASH_TABLE_MIN_SHIFT);
675 hash_table->nnodes = 0;
676 hash_table->noccupied = 0;
677 hash_table->hash_func = hash_func ? hash_func : g_direct_hash;
678 hash_table->key_equal_func = key_equal_func;
679 hash_table->ref_count = 1;
680 #ifndef G_DISABLE_ASSERT
681 hash_table->version = 0;
682 #endif
683 hash_table->key_destroy_func = key_destroy_func;
684 hash_table->value_destroy_func = value_destroy_func;
685 hash_table->keys = g_new0 (gpointer, hash_table->size);
686 hash_table->values = hash_table->keys;
687 hash_table->hashes = g_new0 (guint, hash_table->size);
689 return hash_table;
693 * g_hash_table_iter_init:
694 * @iter: an uninitialized #GHashTableIter
695 * @hash_table: a #GHashTable
697 * Initializes a key/value pair iterator and associates it with
698 * @hash_table. Modifying the hash table after calling this function
699 * invalidates the returned iterator.
700 * |[
701 * GHashTableIter iter;
702 * gpointer key, value;
704 * g_hash_table_iter_init (&iter, hash_table);
705 * while (g_hash_table_iter_next (&iter, &key, &value))
707 * /&ast; do something with key and value &ast;/
709 * ]|
711 * Since: 2.16
713 void
714 g_hash_table_iter_init (GHashTableIter *iter,
715 GHashTable *hash_table)
717 RealIter *ri = (RealIter *) iter;
719 g_return_if_fail (iter != NULL);
720 g_return_if_fail (hash_table != NULL);
722 ri->hash_table = hash_table;
723 ri->position = -1;
724 #ifndef G_DISABLE_ASSERT
725 ri->version = hash_table->version;
726 #endif
730 * g_hash_table_iter_next:
731 * @iter: an initialized #GHashTableIter
732 * @key: a location to store the key, or %NULL
733 * @value: a location to store the value, or %NULL
735 * Advances @iter and retrieves the key and/or value that are now
736 * pointed to as a result of this advancement. If %FALSE is returned,
737 * @key and @value are not set, and the iterator becomes invalid.
739 * Return value: %FALSE if the end of the #GHashTable has been reached.
741 * Since: 2.16
743 gboolean
744 g_hash_table_iter_next (GHashTableIter *iter,
745 gpointer *key,
746 gpointer *value)
748 RealIter *ri = (RealIter *) iter;
749 gint position;
751 g_return_val_if_fail (iter != NULL, FALSE);
752 #ifndef G_DISABLE_ASSERT
753 g_return_val_if_fail (ri->version == ri->hash_table->version, FALSE);
754 #endif
755 g_return_val_if_fail (ri->position < ri->hash_table->size, FALSE);
757 position = ri->position;
761 position++;
762 if (position >= ri->hash_table->size)
764 ri->position = position;
765 return FALSE;
768 while (!HASH_IS_REAL (ri->hash_table->hashes[position]));
770 if (key != NULL)
771 *key = ri->hash_table->keys[position];
772 if (value != NULL)
773 *value = ri->hash_table->values[position];
775 ri->position = position;
776 return TRUE;
780 * g_hash_table_iter_get_hash_table:
781 * @iter: an initialized #GHashTableIter
783 * Returns the #GHashTable associated with @iter.
785 * Return value: the #GHashTable associated with @iter.
787 * Since: 2.16
789 GHashTable *
790 g_hash_table_iter_get_hash_table (GHashTableIter *iter)
792 g_return_val_if_fail (iter != NULL, NULL);
794 return ((RealIter *) iter)->hash_table;
797 static void
798 iter_remove_or_steal (RealIter *ri, gboolean notify)
800 g_return_if_fail (ri != NULL);
801 #ifndef G_DISABLE_ASSERT
802 g_return_if_fail (ri->version == ri->hash_table->version);
803 #endif
804 g_return_if_fail (ri->position >= 0);
805 g_return_if_fail (ri->position < ri->hash_table->size);
807 g_hash_table_remove_node (ri->hash_table, ri->position, notify);
809 #ifndef G_DISABLE_ASSERT
810 ri->version++;
811 ri->hash_table->version++;
812 #endif
816 * g_hash_table_iter_remove:
817 * @iter: an initialized #GHashTableIter
819 * Removes the key/value pair currently pointed to by the iterator
820 * from its associated #GHashTable. Can only be called after
821 * g_hash_table_iter_next() returned %TRUE, and cannot be called
822 * more than once for the same key/value pair.
824 * If the #GHashTable was created using g_hash_table_new_full(),
825 * the key and value are freed using the supplied destroy functions,
826 * otherwise you have to make sure that any dynamically allocated
827 * values are freed yourself.
829 * Since: 2.16
831 void
832 g_hash_table_iter_remove (GHashTableIter *iter)
834 iter_remove_or_steal ((RealIter *) iter, TRUE);
838 * g_hash_table_insert_node:
839 * @hash_table: our #GHashTable
840 * @node_index: pointer to node to insert/replace
841 * @key_hash: key hash
842 * @key: key to replace with, or %NULL
843 * @value: value to replace with
844 * @keep_new_key: whether to replace the key in the node with @key
845 * @reusing_key: whether @key was taken out of the existing node
847 * Inserts a value at @node_index in the hash table and updates it.
849 * If @key has been taken out of the existing node (ie it is not
850 * passed in via a g_hash_table_insert/replace) call, then @reusing_key
851 * should be %TRUE.
853 static void
854 g_hash_table_insert_node (GHashTable *hash_table,
855 guint node_index,
856 guint key_hash,
857 gpointer key,
858 gpointer value,
859 gboolean keep_new_key,
860 gboolean reusing_key)
862 guint old_hash;
863 gpointer old_key;
864 gpointer old_value;
866 if (G_UNLIKELY (hash_table->keys == hash_table->values && key != value))
867 hash_table->values = g_memdup (hash_table->keys, sizeof (gpointer) * hash_table->size);
869 old_hash = hash_table->hashes[node_index];
870 old_key = hash_table->keys[node_index];
871 old_value = hash_table->values[node_index];
873 if (HASH_IS_REAL (old_hash))
875 if (keep_new_key)
876 hash_table->keys[node_index] = key;
877 hash_table->values[node_index] = value;
879 else
881 hash_table->keys[node_index] = key;
882 hash_table->values[node_index] = value;
883 hash_table->hashes[node_index] = key_hash;
885 hash_table->nnodes++;
887 if (HASH_IS_UNUSED (old_hash))
889 /* We replaced an empty node, and not a tombstone */
890 hash_table->noccupied++;
891 g_hash_table_maybe_resize (hash_table);
894 #ifndef G_DISABLE_ASSERT
895 hash_table->version++;
896 #endif
899 if (HASH_IS_REAL (old_hash))
901 if (hash_table->key_destroy_func && !reusing_key)
902 hash_table->key_destroy_func (keep_new_key ? old_key : key);
903 if (hash_table->value_destroy_func)
904 hash_table->value_destroy_func (old_value);
909 * g_hash_table_iter_replace:
910 * @iter: an initialized #GHashTableIter
911 * @value: the value to replace with
913 * Replaces the value currently pointed to by the iterator
914 * from its associated #GHashTable. Can only be called after
915 * g_hash_table_iter_next() returned %TRUE.
917 * If you supplied a @value_destroy_func when creating the
918 * #GHashTable, the old value is freed using that function.
920 * Since: 2.30
922 void
923 g_hash_table_iter_replace (GHashTableIter *iter,
924 gpointer value)
926 RealIter *ri;
927 guint node_hash;
928 gpointer key;
930 ri = (RealIter *) iter;
932 g_return_if_fail (ri != NULL);
933 #ifndef G_DISABLE_ASSERT
934 g_return_if_fail (ri->version == ri->hash_table->version);
935 #endif
936 g_return_if_fail (ri->position >= 0);
937 g_return_if_fail (ri->position < ri->hash_table->size);
939 node_hash = ri->hash_table->hashes[ri->position];
940 key = ri->hash_table->keys[ri->position];
942 g_hash_table_insert_node (ri->hash_table, ri->position, node_hash, key, value, TRUE, TRUE);
944 #ifndef G_DISABLE_ASSERT
945 ri->version++;
946 ri->hash_table->version++;
947 #endif
951 * g_hash_table_iter_steal:
952 * @iter: an initialized #GHashTableIter
954 * Removes the key/value pair currently pointed to by the
955 * iterator from its associated #GHashTable, without calling
956 * the key and value destroy functions. Can only be called
957 * after g_hash_table_iter_next() returned %TRUE, and cannot
958 * be called more than once for the same key/value pair.
960 * Since: 2.16
962 void
963 g_hash_table_iter_steal (GHashTableIter *iter)
965 iter_remove_or_steal ((RealIter *) iter, FALSE);
970 * g_hash_table_ref:
971 * @hash_table: a valid #GHashTable
973 * Atomically increments the reference count of @hash_table by one.
974 * This function is MT-safe and may be called from any thread.
976 * Return value: the passed in #GHashTable
978 * Since: 2.10
980 GHashTable *
981 g_hash_table_ref (GHashTable *hash_table)
983 g_return_val_if_fail (hash_table != NULL, NULL);
985 g_atomic_int_inc (&hash_table->ref_count);
987 return hash_table;
991 * g_hash_table_unref:
992 * @hash_table: a valid #GHashTable
994 * Atomically decrements the reference count of @hash_table by one.
995 * If the reference count drops to 0, all keys and values will be
996 * destroyed, and all memory allocated by the hash table is released.
997 * This function is MT-safe and may be called from any thread.
999 * Since: 2.10
1001 void
1002 g_hash_table_unref (GHashTable *hash_table)
1004 g_return_if_fail (hash_table != NULL);
1006 if (g_atomic_int_dec_and_test (&hash_table->ref_count))
1008 g_hash_table_remove_all_nodes (hash_table, TRUE);
1009 if (hash_table->keys != hash_table->values)
1010 g_free (hash_table->values);
1011 g_free (hash_table->keys);
1012 g_free (hash_table->hashes);
1013 g_slice_free (GHashTable, hash_table);
1018 * g_hash_table_destroy:
1019 * @hash_table: a #GHashTable
1021 * Destroys all keys and values in the #GHashTable and decrements its
1022 * reference count by 1. If keys and/or values are dynamically allocated,
1023 * you should either free them first or create the #GHashTable with destroy
1024 * notifiers using g_hash_table_new_full(). In the latter case the destroy
1025 * functions you supplied will be called on all keys and values during the
1026 * destruction phase.
1028 void
1029 g_hash_table_destroy (GHashTable *hash_table)
1031 g_return_if_fail (hash_table != NULL);
1033 g_hash_table_remove_all (hash_table);
1034 g_hash_table_unref (hash_table);
1038 * g_hash_table_lookup:
1039 * @hash_table: a #GHashTable
1040 * @key: the key to look up
1042 * Looks up a key in a #GHashTable. Note that this function cannot
1043 * distinguish between a key that is not present and one which is present
1044 * and has the value %NULL. If you need this distinction, use
1045 * g_hash_table_lookup_extended().
1047 * Return value: the associated value, or %NULL if the key is not found
1049 gpointer
1050 g_hash_table_lookup (GHashTable *hash_table,
1051 gconstpointer key)
1053 guint node_index;
1054 guint node_hash;
1056 g_return_val_if_fail (hash_table != NULL, NULL);
1058 node_index = g_hash_table_lookup_node (hash_table, key, &node_hash);
1060 return HASH_IS_REAL (hash_table->hashes[node_index])
1061 ? hash_table->values[node_index]
1062 : NULL;
1066 * g_hash_table_lookup_extended:
1067 * @hash_table: a #GHashTable
1068 * @lookup_key: the key to look up
1069 * @orig_key: return location for the original key, or %NULL
1070 * @value: return location for the value associated with the key, or %NULL
1072 * Looks up a key in the #GHashTable, returning the original key and the
1073 * associated value and a #gboolean which is %TRUE if the key was found. This
1074 * is useful if you need to free the memory allocated for the original key,
1075 * for example before calling g_hash_table_remove().
1077 * You can actually pass %NULL for @lookup_key to test
1078 * whether the %NULL key exists, provided the hash and equal functions
1079 * of @hash_table are %NULL-safe.
1081 * Return value: %TRUE if the key was found in the #GHashTable
1083 gboolean
1084 g_hash_table_lookup_extended (GHashTable *hash_table,
1085 gconstpointer lookup_key,
1086 gpointer *orig_key,
1087 gpointer *value)
1089 guint node_index;
1090 guint node_hash;
1092 g_return_val_if_fail (hash_table != NULL, FALSE);
1094 node_index = g_hash_table_lookup_node (hash_table, lookup_key, &node_hash);
1096 if (!HASH_IS_REAL (hash_table->hashes[node_index]))
1097 return FALSE;
1099 if (orig_key)
1100 *orig_key = hash_table->keys[node_index];
1102 if (value)
1103 *value = hash_table->values[node_index];
1105 return TRUE;
1109 * g_hash_table_insert_internal:
1110 * @hash_table: our #GHashTable
1111 * @key: the key to insert
1112 * @value: the value to insert
1113 * @keep_new_key: if %TRUE and this key already exists in the table
1114 * then call the destroy notify function on the old key. If %FALSE
1115 * then call the destroy notify function on the new key.
1117 * Implements the common logic for the g_hash_table_insert() and
1118 * g_hash_table_replace() functions.
1120 * Do a lookup of @key. If it is found, replace it with the new
1121 * @value (and perhaps the new @key). If it is not found, create
1122 * a new node.
1124 static void
1125 g_hash_table_insert_internal (GHashTable *hash_table,
1126 gpointer key,
1127 gpointer value,
1128 gboolean keep_new_key)
1130 guint key_hash;
1131 guint node_index;
1133 g_return_if_fail (hash_table != NULL);
1135 node_index = g_hash_table_lookup_node (hash_table, key, &key_hash);
1137 g_hash_table_insert_node (hash_table, node_index, key_hash, key, value, keep_new_key, FALSE);
1141 * g_hash_table_insert:
1142 * @hash_table: a #GHashTable
1143 * @key: a key to insert
1144 * @value: the value to associate with the key
1146 * Inserts a new key and value into a #GHashTable.
1148 * If the key already exists in the #GHashTable its current
1149 * value is replaced with the new value. If you supplied a
1150 * @value_destroy_func when creating the #GHashTable, the old
1151 * value is freed using that function. If you supplied a
1152 * @key_destroy_func when creating the #GHashTable, the passed
1153 * key is freed using that function.
1155 void
1156 g_hash_table_insert (GHashTable *hash_table,
1157 gpointer key,
1158 gpointer value)
1160 g_hash_table_insert_internal (hash_table, key, value, FALSE);
1164 * g_hash_table_replace:
1165 * @hash_table: a #GHashTable
1166 * @key: a key to insert
1167 * @value: the value to associate with the key
1169 * Inserts a new key and value into a #GHashTable similar to
1170 * g_hash_table_insert(). The difference is that if the key
1171 * already exists in the #GHashTable, it gets replaced by the
1172 * new key. If you supplied a @value_destroy_func when creating
1173 * the #GHashTable, the old value is freed using that function.
1174 * If you supplied a @key_destroy_func when creating the
1175 * #GHashTable, the old key is freed using that function.
1177 void
1178 g_hash_table_replace (GHashTable *hash_table,
1179 gpointer key,
1180 gpointer value)
1182 g_hash_table_insert_internal (hash_table, key, value, TRUE);
1186 * g_hash_table_remove_internal:
1187 * @hash_table: our #GHashTable
1188 * @key: the key to remove
1189 * @notify: %TRUE if the destroy notify handlers are to be called
1190 * Return value: %TRUE if a node was found and removed, else %FALSE
1192 * Implements the common logic for the g_hash_table_remove() and
1193 * g_hash_table_steal() functions.
1195 * Do a lookup of @key and remove it if it is found, calling the
1196 * destroy notify handlers only if @notify is %TRUE.
1198 static gboolean
1199 g_hash_table_remove_internal (GHashTable *hash_table,
1200 gconstpointer key,
1201 gboolean notify)
1203 guint node_index;
1204 guint node_hash;
1206 g_return_val_if_fail (hash_table != NULL, FALSE);
1208 node_index = g_hash_table_lookup_node (hash_table, key, &node_hash);
1210 if (!HASH_IS_REAL (hash_table->hashes[node_index]))
1211 return FALSE;
1213 g_hash_table_remove_node (hash_table, node_index, notify);
1214 g_hash_table_maybe_resize (hash_table);
1216 #ifndef G_DISABLE_ASSERT
1217 hash_table->version++;
1218 #endif
1220 return TRUE;
1224 * g_hash_table_remove:
1225 * @hash_table: a #GHashTable
1226 * @key: the key to remove
1228 * Removes a key and its associated value from a #GHashTable.
1230 * If the #GHashTable was created using g_hash_table_new_full(), the
1231 * key and value are freed using the supplied destroy functions, otherwise
1232 * you have to make sure that any dynamically allocated values are freed
1233 * yourself.
1235 * Returns: %TRUE if the key was found and removed from the #GHashTable
1237 gboolean
1238 g_hash_table_remove (GHashTable *hash_table,
1239 gconstpointer key)
1241 return g_hash_table_remove_internal (hash_table, key, TRUE);
1245 * g_hash_table_steal:
1246 * @hash_table: a #GHashTable
1247 * @key: the key to remove
1249 * Removes a key and its associated value from a #GHashTable without
1250 * calling the key and value destroy functions.
1252 * Returns: %TRUE if the key was found and removed from the #GHashTable
1254 gboolean
1255 g_hash_table_steal (GHashTable *hash_table,
1256 gconstpointer key)
1258 return g_hash_table_remove_internal (hash_table, key, FALSE);
1262 * g_hash_table_remove_all:
1263 * @hash_table: a #GHashTable
1265 * Removes all keys and their associated values from a #GHashTable.
1267 * If the #GHashTable was created using g_hash_table_new_full(),
1268 * the keys and values are freed using the supplied destroy functions,
1269 * otherwise you have to make sure that any dynamically allocated
1270 * values are freed yourself.
1272 * Since: 2.12
1274 void
1275 g_hash_table_remove_all (GHashTable *hash_table)
1277 g_return_if_fail (hash_table != NULL);
1279 #ifndef G_DISABLE_ASSERT
1280 if (hash_table->nnodes != 0)
1281 hash_table->version++;
1282 #endif
1284 g_hash_table_remove_all_nodes (hash_table, TRUE);
1285 g_hash_table_maybe_resize (hash_table);
1289 * g_hash_table_steal_all:
1290 * @hash_table: a #GHashTable
1292 * Removes all keys and their associated values from a #GHashTable
1293 * without calling the key and value destroy functions.
1295 * Since: 2.12
1297 void
1298 g_hash_table_steal_all (GHashTable *hash_table)
1300 g_return_if_fail (hash_table != NULL);
1302 #ifndef G_DISABLE_ASSERT
1303 if (hash_table->nnodes != 0)
1304 hash_table->version++;
1305 #endif
1307 g_hash_table_remove_all_nodes (hash_table, FALSE);
1308 g_hash_table_maybe_resize (hash_table);
1312 * g_hash_table_foreach_remove_or_steal:
1313 * @hash_table: a #GHashTable
1314 * @func: the user's callback function
1315 * @user_data: data for @func
1316 * @notify: %TRUE if the destroy notify handlers are to be called
1318 * Implements the common logic for g_hash_table_foreach_remove()
1319 * and g_hash_table_foreach_steal().
1321 * Iterates over every node in the table, calling @func with the key
1322 * and value of the node (and @user_data). If @func returns %TRUE the
1323 * node is removed from the table.
1325 * If @notify is true then the destroy notify handlers will be called
1326 * for each removed node.
1328 static guint
1329 g_hash_table_foreach_remove_or_steal (GHashTable *hash_table,
1330 GHRFunc func,
1331 gpointer user_data,
1332 gboolean notify)
1334 guint deleted = 0;
1335 gint i;
1336 #ifndef G_DISABLE_ASSERT
1337 gint version = hash_table->version;
1338 #endif
1340 for (i = 0; i < hash_table->size; i++)
1342 guint node_hash = hash_table->hashes[i];
1343 gpointer node_key = hash_table->keys[i];
1344 gpointer node_value = hash_table->values[i];
1346 if (HASH_IS_REAL (node_hash) &&
1347 (* func) (node_key, node_value, user_data))
1349 g_hash_table_remove_node (hash_table, i, notify);
1350 deleted++;
1353 #ifndef G_DISABLE_ASSERT
1354 g_return_val_if_fail (version == hash_table->version, 0);
1355 #endif
1358 g_hash_table_maybe_resize (hash_table);
1360 #ifndef G_DISABLE_ASSERT
1361 if (deleted > 0)
1362 hash_table->version++;
1363 #endif
1365 return deleted;
1369 * g_hash_table_foreach_remove:
1370 * @hash_table: a #GHashTable
1371 * @func: the function to call for each key/value pair
1372 * @user_data: user data to pass to the function
1374 * Calls the given function for each key/value pair in the
1375 * #GHashTable. If the function returns %TRUE, then the key/value
1376 * pair is removed from the #GHashTable. If you supplied key or
1377 * value destroy functions when creating the #GHashTable, they are
1378 * used to free the memory allocated for the removed keys and values.
1380 * See #GHashTableIter for an alternative way to loop over the
1381 * key/value pairs in the hash table.
1383 * Return value: the number of key/value pairs removed
1385 guint
1386 g_hash_table_foreach_remove (GHashTable *hash_table,
1387 GHRFunc func,
1388 gpointer user_data)
1390 g_return_val_if_fail (hash_table != NULL, 0);
1391 g_return_val_if_fail (func != NULL, 0);
1393 return g_hash_table_foreach_remove_or_steal (hash_table, func, user_data, TRUE);
1397 * g_hash_table_foreach_steal:
1398 * @hash_table: a #GHashTable
1399 * @func: the function to call for each key/value pair
1400 * @user_data: user data to pass to the function
1402 * Calls the given function for each key/value pair in the
1403 * #GHashTable. If the function returns %TRUE, then the key/value
1404 * pair is removed from the #GHashTable, but no key or value
1405 * destroy functions are called.
1407 * See #GHashTableIter for an alternative way to loop over the
1408 * key/value pairs in the hash table.
1410 * Return value: the number of key/value pairs removed.
1412 guint
1413 g_hash_table_foreach_steal (GHashTable *hash_table,
1414 GHRFunc func,
1415 gpointer user_data)
1417 g_return_val_if_fail (hash_table != NULL, 0);
1418 g_return_val_if_fail (func != NULL, 0);
1420 return g_hash_table_foreach_remove_or_steal (hash_table, func, user_data, FALSE);
1424 * g_hash_table_foreach:
1425 * @hash_table: a #GHashTable
1426 * @func: the function to call for each key/value pair
1427 * @user_data: user data to pass to the function
1429 * Calls the given function for each of the key/value pairs in the
1430 * #GHashTable. The function is passed the key and value of each
1431 * pair, and the given @user_data parameter. The hash table may not
1432 * be modified while iterating over it (you can't add/remove
1433 * items). To remove all items matching a predicate, use
1434 * g_hash_table_foreach_remove().
1436 * See g_hash_table_find() for performance caveats for linear
1437 * order searches in contrast to g_hash_table_lookup().
1439 void
1440 g_hash_table_foreach (GHashTable *hash_table,
1441 GHFunc func,
1442 gpointer user_data)
1444 gint i;
1445 #ifndef G_DISABLE_ASSERT
1446 gint version = hash_table->version;
1447 #endif
1449 g_return_if_fail (hash_table != NULL);
1450 g_return_if_fail (func != NULL);
1452 for (i = 0; i < hash_table->size; i++)
1454 guint node_hash = hash_table->hashes[i];
1455 gpointer node_key = hash_table->keys[i];
1456 gpointer node_value = hash_table->values[i];
1458 if (HASH_IS_REAL (node_hash))
1459 (* func) (node_key, node_value, user_data);
1461 #ifndef G_DISABLE_ASSERT
1462 g_return_if_fail (version == hash_table->version);
1463 #endif
1468 * g_hash_table_find:
1469 * @hash_table: a #GHashTable
1470 * @predicate: function to test the key/value pairs for a certain property
1471 * @user_data: user data to pass to the function
1473 * Calls the given function for key/value pairs in the #GHashTable
1474 * until @predicate returns %TRUE. The function is passed the key
1475 * and value of each pair, and the given @user_data parameter. The
1476 * hash table may not be modified while iterating over it (you can't
1477 * add/remove items).
1479 * Note, that hash tables are really only optimized for forward
1480 * lookups, i.e. g_hash_table_lookup(). So code that frequently issues
1481 * g_hash_table_find() or g_hash_table_foreach() (e.g. in the order of
1482 * once per every entry in a hash table) should probably be reworked
1483 * to use additional or different data structures for reverse lookups
1484 * (keep in mind that an O(n) find/foreach operation issued for all n
1485 * values in a hash table ends up needing O(n*n) operations).
1487 * Return value: The value of the first key/value pair is returned,
1488 * for which @predicate evaluates to %TRUE. If no pair with the
1489 * requested property is found, %NULL is returned.
1491 * Since: 2.4
1493 gpointer
1494 g_hash_table_find (GHashTable *hash_table,
1495 GHRFunc predicate,
1496 gpointer user_data)
1498 gint i;
1499 #ifndef G_DISABLE_ASSERT
1500 gint version = hash_table->version;
1501 #endif
1502 gboolean match;
1504 g_return_val_if_fail (hash_table != NULL, NULL);
1505 g_return_val_if_fail (predicate != NULL, NULL);
1507 match = FALSE;
1509 for (i = 0; i < hash_table->size; i++)
1511 guint node_hash = hash_table->hashes[i];
1512 gpointer node_key = hash_table->keys[i];
1513 gpointer node_value = hash_table->values[i];
1515 if (HASH_IS_REAL (node_hash))
1516 match = predicate (node_key, node_value, user_data);
1518 #ifndef G_DISABLE_ASSERT
1519 g_return_val_if_fail (version == hash_table->version, NULL);
1520 #endif
1522 if (match)
1523 return node_value;
1526 return NULL;
1530 * g_hash_table_size:
1531 * @hash_table: a #GHashTable
1533 * Returns the number of elements contained in the #GHashTable.
1535 * Return value: the number of key/value pairs in the #GHashTable.
1537 guint
1538 g_hash_table_size (GHashTable *hash_table)
1540 g_return_val_if_fail (hash_table != NULL, 0);
1542 return hash_table->nnodes;
1546 * g_hash_table_get_keys:
1547 * @hash_table: a #GHashTable
1549 * Retrieves every key inside @hash_table. The returned data
1550 * is valid until @hash_table is modified.
1552 * Return value: a #GList containing all the keys inside the hash
1553 * table. The content of the list is owned by the hash table and
1554 * should not be modified or freed. Use g_list_free() when done
1555 * using the list.
1557 * Since: 2.14
1559 GList *
1560 g_hash_table_get_keys (GHashTable *hash_table)
1562 gint i;
1563 GList *retval;
1565 g_return_val_if_fail (hash_table != NULL, NULL);
1567 retval = NULL;
1568 for (i = 0; i < hash_table->size; i++)
1570 if (HASH_IS_REAL (hash_table->hashes[i]))
1571 retval = g_list_prepend (retval, hash_table->keys[i]);
1574 return retval;
1578 * g_hash_table_get_values:
1579 * @hash_table: a #GHashTable
1581 * Retrieves every value inside @hash_table. The returned data
1582 * is valid until @hash_table is modified.
1584 * Return value: a #GList containing all the values inside the hash
1585 * table. The content of the list is owned by the hash table and
1586 * should not be modified or freed. Use g_list_free() when done
1587 * using the list.
1589 * Since: 2.14
1591 GList *
1592 g_hash_table_get_values (GHashTable *hash_table)
1594 gint i;
1595 GList *retval;
1597 g_return_val_if_fail (hash_table != NULL, NULL);
1599 retval = NULL;
1600 for (i = 0; i < hash_table->size; i++)
1602 if (HASH_IS_REAL (hash_table->hashes[i]))
1603 retval = g_list_prepend (retval, hash_table->values[i]);
1606 return retval;
1609 /* Hash functions.
1613 * g_str_equal:
1614 * @v1: a key
1615 * @v2: a key to compare with @v1
1617 * Compares two strings for byte-by-byte equality and returns %TRUE
1618 * if they are equal. It can be passed to g_hash_table_new() as the
1619 * @key_equal_func parameter, when using non-%NULL strings as keys in a
1620 * #GHashTable.
1622 * Note that this function is primarily meant as a hash table comparison
1623 * function. For a general-purpose, %NULL-safe string comparison function,
1624 * see g_strcmp0().
1626 * Returns: %TRUE if the two keys match
1628 gboolean
1629 g_str_equal (gconstpointer v1,
1630 gconstpointer v2)
1632 const gchar *string1 = v1;
1633 const gchar *string2 = v2;
1635 return strcmp (string1, string2) == 0;
1639 * g_str_hash:
1640 * @v: a string key
1642 * Converts a string to a hash value.
1644 * This function implements the widely used "djb" hash apparently posted
1645 * by Daniel Bernstein to comp.lang.c some time ago. The 32 bit
1646 * unsigned hash value starts at 5381 and for each byte 'c' in the
1647 * string, is updated: <literal>hash = hash * 33 + c</literal>. This
1648 * function uses the signed value of each byte.
1650 * It can be passed to g_hash_table_new() as the @hash_func parameter,
1651 * when using non-%NULL strings as keys in a #GHashTable.
1653 * Returns: a hash value corresponding to the key
1655 guint
1656 g_str_hash (gconstpointer v)
1658 const signed char *p;
1659 guint32 h = 5381;
1661 for (p = v; *p != '\0'; p++)
1662 h = (h << 5) + h + *p;
1664 return h;
1668 * g_direct_hash:
1669 * @v: (allow-none): a #gpointer key
1671 * Converts a gpointer to a hash value.
1672 * It can be passed to g_hash_table_new() as the @hash_func parameter,
1673 * when using opaque pointers compared by pointer value as keys in a
1674 * #GHashTable.
1676 * This hash function is also appropriate for keys that are integers stored
1677 * in pointers, such as <literal>GINT_TO_POINTER (n)</literal>.
1679 * Returns: a hash value corresponding to the key.
1681 guint
1682 g_direct_hash (gconstpointer v)
1684 return GPOINTER_TO_UINT (v);
1688 * g_direct_equal:
1689 * @v1: (allow-none): a key
1690 * @v2: (allow-none): a key to compare with @v1
1692 * Compares two #gpointer arguments and returns %TRUE if they are equal.
1693 * It can be passed to g_hash_table_new() as the @key_equal_func
1694 * parameter, when using opaque pointers compared by pointer value as keys
1695 * in a #GHashTable.
1697 * This equality function is also appropriate for keys that are integers stored
1698 * in pointers, such as <literal>GINT_TO_POINTER (n)</literal>.
1700 * Returns: %TRUE if the two keys match.
1702 gboolean
1703 g_direct_equal (gconstpointer v1,
1704 gconstpointer v2)
1706 return v1 == v2;
1710 * g_int_equal:
1711 * @v1: a pointer to a #gint key
1712 * @v2: a pointer to a #gint key to compare with @v1
1714 * Compares the two #gint values being pointed to and returns
1715 * %TRUE if they are equal.
1716 * It can be passed to g_hash_table_new() as the @key_equal_func
1717 * parameter, when using non-%NULL pointers to integers as keys in a
1718 * #GHashTable.
1720 * Note that this function acts on pointers to #gint, not on #gint directly:
1721 * if your hash table's keys are of the form
1722 * <literal>GINT_TO_POINTER (n)</literal>, use g_direct_equal() instead.
1724 * Returns: %TRUE if the two keys match.
1726 gboolean
1727 g_int_equal (gconstpointer v1,
1728 gconstpointer v2)
1730 return *((const gint*) v1) == *((const gint*) v2);
1734 * g_int_hash:
1735 * @v: a pointer to a #gint key
1737 * Converts a pointer to a #gint to a hash value.
1738 * It can be passed to g_hash_table_new() as the @hash_func parameter,
1739 * when using non-%NULL pointers to integer values as keys in a #GHashTable.
1741 * Note that this function acts on pointers to #gint, not on #gint directly:
1742 * if your hash table's keys are of the form
1743 * <literal>GINT_TO_POINTER (n)</literal>, use g_direct_hash() instead.
1745 * Returns: a hash value corresponding to the key.
1747 guint
1748 g_int_hash (gconstpointer v)
1750 return *(const gint*) v;
1754 * g_int64_equal:
1755 * @v1: a pointer to a #gint64 key
1756 * @v2: a pointer to a #gint64 key to compare with @v1
1758 * Compares the two #gint64 values being pointed to and returns
1759 * %TRUE if they are equal.
1760 * It can be passed to g_hash_table_new() as the @key_equal_func
1761 * parameter, when using non-%NULL pointers to 64-bit integers as keys in a
1762 * #GHashTable.
1764 * Returns: %TRUE if the two keys match.
1766 * Since: 2.22
1768 gboolean
1769 g_int64_equal (gconstpointer v1,
1770 gconstpointer v2)
1772 return *((const gint64*) v1) == *((const gint64*) v2);
1776 * g_int64_hash:
1777 * @v: a pointer to a #gint64 key
1779 * Converts a pointer to a #gint64 to a hash value.
1781 * It can be passed to g_hash_table_new() as the @hash_func parameter,
1782 * when using non-%NULL pointers to 64-bit integer values as keys in a
1783 * #GHashTable.
1785 * Returns: a hash value corresponding to the key.
1787 * Since: 2.22
1789 guint
1790 g_int64_hash (gconstpointer v)
1792 return (guint) *(const gint64*) v;
1796 * g_double_equal:
1797 * @v1: a pointer to a #gdouble key
1798 * @v2: a pointer to a #gdouble key to compare with @v1
1800 * Compares the two #gdouble values being pointed to and returns
1801 * %TRUE if they are equal.
1802 * It can be passed to g_hash_table_new() as the @key_equal_func
1803 * parameter, when using non-%NULL pointers to doubles as keys in a
1804 * #GHashTable.
1806 * Returns: %TRUE if the two keys match.
1808 * Since: 2.22
1810 gboolean
1811 g_double_equal (gconstpointer v1,
1812 gconstpointer v2)
1814 return *((const gdouble*) v1) == *((const gdouble*) v2);
1818 * g_double_hash:
1819 * @v: a pointer to a #gdouble key
1821 * Converts a pointer to a #gdouble to a hash value.
1822 * It can be passed to g_hash_table_new() as the @hash_func parameter,
1823 * It can be passed to g_hash_table_new() as the @hash_func parameter,
1824 * when using non-%NULL pointers to doubles as keys in a #GHashTable.
1826 * Returns: a hash value corresponding to the key.
1828 * Since: 2.22
1830 guint
1831 g_double_hash (gconstpointer v)
1833 return (guint) *(const gdouble*) v;