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 */
37 #include "gstrfuncs.h"
39 #include "gtestutils.h"
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
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().
86 * <title>Using a GHashTable as a set</title>
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.
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);
105 * set_insert (GHashTable *set,
108 * g_hash_table_insert (set, element, element);
112 * set_contains (GHashTable *set,
115 * return g_hash_table_lookup_extended (set, element, NULL, NULL);
119 * set_remove (GHashTable *set,
122 * return g_hash_table_remove (set, element);
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.
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
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().
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
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
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.
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)
238 gint noccupied
; /* nnodes + tombstones */
245 GEqualFunc key_equal_func
;
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).
255 GDestroyNotify key_destroy_func
;
256 GDestroyNotify value_destroy_func
;
261 GHashTable
*hash_table
;
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
[] =
292 65521, /* For 1 << 16 */
307 2147483647 /* For 1 << 31 */
311 g_hash_table_set_shift (GHashTable
*hash_table
, gint shift
)
316 hash_table
->size
= 1 << shift
;
317 hash_table
->mod
= prime_mod
[shift
];
319 for (i
= 0; i
< shift
; i
++)
325 hash_table
->mask
= mask
;
329 g_hash_table_find_closest_shift (gint n
)
340 g_hash_table_set_shift_from_size (GHashTable
*hash_table
, gint size
)
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
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
374 g_hash_table_lookup_node (GHashTable
*hash_table
,
381 guint first_tombstone
= 0;
382 gboolean have_tombstone
= FALSE
;
385 hash_value
= hash_table
->hash_func (key
);
386 if (G_UNLIKELY (!HASH_IS_REAL (hash_value
)))
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
))
409 else if (node_key
== key
)
414 else if (HASH_IS_TOMBSTONE (node_hash
) && !have_tombstone
)
416 first_tombstone
= node_index
;
417 have_tombstone
= TRUE
;
422 node_index
&= hash_table
->mask
;
423 node_hash
= hash_table
->hashes
[node_index
];
427 return first_tombstone
;
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.
445 g_hash_table_remove_node (GHashTable
*hash_table
,
452 key
= hash_table
->keys
[i
];
453 value
= hash_table
->values
[i
];
455 /* Erect tombstone */
456 hash_table
->hashes
[i
] = TOMBSTONE_HASH_VALUE
;
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.
484 g_hash_table_remove_all_nodes (GHashTable
*hash_table
,
491 hash_table
->nnodes
= 0;
492 hash_table
->noccupied
= 0;
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
));
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.
543 g_hash_table_resize (GHashTable
*hash_table
)
546 gpointer
*new_values
;
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
;
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
];
567 if (!HASH_IS_REAL (node_hash
))
570 hash_val
= node_hash
% hash_table
->mod
;
572 while (!HASH_IS_UNUSED (new_hashes
[hash_val
]))
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.
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
);
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
637 * Return value: a new #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
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;
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
);
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.
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 * /* do something with key and value */
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
;
724 #ifndef G_DISABLE_ASSERT
725 ri
->version
= hash_table
->version
;
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.
744 g_hash_table_iter_next (GHashTableIter
*iter
,
748 RealIter
*ri
= (RealIter
*) iter
;
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
);
755 g_return_val_if_fail (ri
->position
< ri
->hash_table
->size
, FALSE
);
757 position
= ri
->position
;
762 if (position
>= ri
->hash_table
->size
)
764 ri
->position
= position
;
768 while (!HASH_IS_REAL (ri
->hash_table
->hashes
[position
]));
771 *key
= ri
->hash_table
->keys
[position
];
773 *value
= ri
->hash_table
->values
[position
];
775 ri
->position
= position
;
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.
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
;
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
);
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
811 ri
->hash_table
->version
++;
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.
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
854 g_hash_table_insert_node (GHashTable
*hash_table
,
859 gboolean keep_new_key
,
860 gboolean reusing_key
)
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
))
876 hash_table
->keys
[node_index
] = key
;
877 hash_table
->values
[node_index
] = value
;
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
++;
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.
923 g_hash_table_iter_replace (GHashTableIter
*iter
,
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
);
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
946 ri
->hash_table
->version
++;
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.
963 g_hash_table_iter_steal (GHashTableIter
*iter
)
965 iter_remove_or_steal ((RealIter
*) iter
, FALSE
);
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
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
);
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.
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.
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
1050 g_hash_table_lookup (GHashTable
*hash_table
,
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
]
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
1084 g_hash_table_lookup_extended (GHashTable
*hash_table
,
1085 gconstpointer lookup_key
,
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
]))
1100 *orig_key
= hash_table
->keys
[node_index
];
1103 *value
= hash_table
->values
[node_index
];
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
1125 g_hash_table_insert_internal (GHashTable
*hash_table
,
1128 gboolean keep_new_key
)
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.
1156 g_hash_table_insert (GHashTable
*hash_table
,
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.
1178 g_hash_table_replace (GHashTable
*hash_table
,
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.
1199 g_hash_table_remove_internal (GHashTable
*hash_table
,
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
]))
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
++;
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
1235 * Returns: %TRUE if the key was found and removed from the #GHashTable
1238 g_hash_table_remove (GHashTable
*hash_table
,
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
1255 g_hash_table_steal (GHashTable
*hash_table
,
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.
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
++;
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.
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
++;
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.
1329 g_hash_table_foreach_remove_or_steal (GHashTable
*hash_table
,
1336 #ifndef G_DISABLE_ASSERT
1337 gint version
= hash_table
->version
;
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
);
1353 #ifndef G_DISABLE_ASSERT
1354 g_return_val_if_fail (version
== hash_table
->version
, 0);
1358 g_hash_table_maybe_resize (hash_table
);
1360 #ifndef G_DISABLE_ASSERT
1362 hash_table
->version
++;
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
1386 g_hash_table_foreach_remove (GHashTable
*hash_table
,
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.
1413 g_hash_table_foreach_steal (GHashTable
*hash_table
,
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().
1440 g_hash_table_foreach (GHashTable
*hash_table
,
1445 #ifndef G_DISABLE_ASSERT
1446 gint version
= hash_table
->version
;
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
);
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.
1494 g_hash_table_find (GHashTable
*hash_table
,
1499 #ifndef G_DISABLE_ASSERT
1500 gint version
= hash_table
->version
;
1504 g_return_val_if_fail (hash_table
!= NULL
, NULL
);
1505 g_return_val_if_fail (predicate
!= NULL
, NULL
);
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
);
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.
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
1560 g_hash_table_get_keys (GHashTable
*hash_table
)
1565 g_return_val_if_fail (hash_table
!= NULL
, 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
]);
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
1592 g_hash_table_get_values (GHashTable
*hash_table
)
1597 g_return_val_if_fail (hash_table
!= NULL
, 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
]);
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
1622 * Note that this function is primarily meant as a hash table comparison
1623 * function. For a general-purpose, %NULL-safe string comparison function,
1626 * Returns: %TRUE if the two keys match
1629 g_str_equal (gconstpointer v1
,
1632 const gchar
*string1
= v1
;
1633 const gchar
*string2
= v2
;
1635 return strcmp (string1
, string2
) == 0;
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
1656 g_str_hash (gconstpointer v
)
1658 const signed char *p
;
1661 for (p
= v
; *p
!= '\0'; p
++)
1662 h
= (h
<< 5) + h
+ *p
;
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
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.
1682 g_direct_hash (gconstpointer v
)
1684 return GPOINTER_TO_UINT (v
);
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
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.
1703 g_direct_equal (gconstpointer v1
,
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
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.
1727 g_int_equal (gconstpointer v1
,
1730 return *((const gint
*) v1
) == *((const gint
*) v2
);
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.
1748 g_int_hash (gconstpointer v
)
1750 return *(const gint
*) v
;
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
1764 * Returns: %TRUE if the two keys match.
1769 g_int64_equal (gconstpointer v1
,
1772 return *((const gint64
*) v1
) == *((const gint64
*) v2
);
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
1785 * Returns: a hash value corresponding to the key.
1790 g_int64_hash (gconstpointer v
)
1792 return (guint
) *(const gint64
*) v
;
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
1806 * Returns: %TRUE if the two keys match.
1811 g_double_equal (gconstpointer v1
,
1814 return *((const gdouble
*) v1
) == *((const gdouble
*) v2
);
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.
1831 g_double_hash (gconstpointer v
)
1833 return (guint
) *(const gdouble
*) v
;