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Diffstat (limited to 'protocols/Sametime/src/glib/ghash.c')
| -rw-r--r-- | protocols/Sametime/src/glib/ghash.c | 1461 |
1 files changed, 1461 insertions, 0 deletions
diff --git a/protocols/Sametime/src/glib/ghash.c b/protocols/Sametime/src/glib/ghash.c new file mode 100644 index 0000000000..5f2df05bde --- /dev/null +++ b/protocols/Sametime/src/glib/ghash.c @@ -0,0 +1,1461 @@ +/* GLIB - Library of useful routines for C programming + * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +/* + * Modified by the GLib Team and others 1997-2000. See the AUTHORS + * file for a list of people on the GLib Team. See the ChangeLog + * files for a list of changes. These files are distributed with + * GLib at ftp://ftp.gtk.org/pub/gtk/. + */ + +/* + * MT safe + */ + +#include "config.h" + +#include <string.h> /* memset */ + +#include "ghash.h" + +#include "gatomic.h" +#include "gtestutils.h" + + +/** + * SECTION: hash_tables + * @title: Hash Tables + * @short_description: associations between keys and values so that + * given a key the value can be found quickly + * + * A #GHashTable provides associations between keys and values which is + * optimized so that given a key, the associated value can be found + * very quickly. + * + * Note that neither keys nor values are copied when inserted into the + * #GHashTable, so they must exist for the lifetime of the #GHashTable. + * This means that the use of static strings is OK, but temporary + * strings (i.e. those created in buffers and those returned by GTK+ + * widgets) should be copied with g_strdup() before being inserted. + * + * If keys or values are dynamically allocated, you must be careful to + * ensure that they are freed when they are removed from the + * #GHashTable, and also when they are overwritten by new insertions + * into the #GHashTable. It is also not advisable to mix static strings + * and dynamically-allocated strings in a #GHashTable, because it then + * becomes difficult to determine whether the string should be freed. + * + * To create a #GHashTable, use g_hash_table_new(). + * + * To insert a key and value into a #GHashTable, use + * g_hash_table_insert(). + * + * To lookup a value corresponding to a given key, use + * g_hash_table_lookup() and g_hash_table_lookup_extended(). + * + * To remove a key and value, use g_hash_table_remove(). + * + * To call a function for each key and value pair use + * g_hash_table_foreach() or use a iterator to iterate over the + * key/value pairs in the hash table, see #GHashTableIter. + * + * To destroy a #GHashTable use g_hash_table_destroy(). + **/ + +/** + * GHashTable: + * + * The #GHashTable struct is an opaque data structure to represent a + * <link linkend="glib-Hash-Tables">Hash Table</link>. It should only be + * accessed via the following functions. + **/ + +/** + * GHashFunc: + * @key: a key. + * @Returns: the hash value corresponding to the key. + * + * Specifies the type of the hash function which is passed to + * g_hash_table_new() when a #GHashTable is created. + * + * The function is passed a key and should return a #guint hash value. + * The functions g_direct_hash(), g_int_hash() and g_str_hash() provide + * hash functions which can be used when the key is a #gpointer, #gint, + * and #gchar* respectively. + * + * <!-- FIXME: Need more here. --> The hash values should be evenly + * distributed over a fairly large range? The modulus is taken with the + * hash table size (a prime number) to find the 'bucket' to place each + * key into. The function should also be very fast, since it is called + * for each key lookup. + **/ + +/** + * GHFunc: + * @key: a key. + * @value: the value corresponding to the key. + * @user_data: user data passed to g_hash_table_foreach(). + * + * Specifies the type of the function passed to g_hash_table_foreach(). + * It is called with each key/value pair, together with the @user_data + * parameter which is passed to g_hash_table_foreach(). + **/ + +/** + * GHRFunc: + * @key: a key. + * @value: the value associated with the key. + * @user_data: user data passed to g_hash_table_remove(). + * @Returns: %TRUE if the key/value pair should be removed from the + * #GHashTable. + * + * Specifies the type of the function passed to + * g_hash_table_foreach_remove(). It is called with each key/value + * pair, together with the @user_data parameter passed to + * g_hash_table_foreach_remove(). It should return %TRUE if the + * key/value pair should be removed from the #GHashTable. + **/ + +/** + * GEqualFunc: + * @a: a value. + * @b: a value to compare with. + * @Returns: %TRUE if @a = @b; %FALSE otherwise. + * + * Specifies the type of a function used to test two values for + * equality. The function should return %TRUE if both values are equal + * and %FALSE otherwise. + **/ + +/** + * GHashTableIter: + * + * A GHashTableIter structure represents an iterator that can be used + * to iterate over the elements of a #GHashTable. GHashTableIter + * structures are typically allocated on the stack and then initialized + * with g_hash_table_iter_init(). + **/ + +#define HASH_TABLE_MIN_SHIFT 3 /* 1 << 3 == 8 buckets */ + +typedef struct _GHashNode GHashNode; + +struct _GHashNode +{ + gpointer key; + gpointer value; + + /* If key_hash == 0, node is not in use + * If key_hash == 1, node is a tombstone + * If key_hash >= 2, node contains data */ + guint key_hash; +}; + +struct _GHashTable +{ + gint size; + gint mod; + guint mask; + gint nnodes; + gint noccupied; /* nnodes + tombstones */ + GHashNode *nodes; + GHashFunc hash_func; + GEqualFunc key_equal_func; + volatile gint ref_count; +#ifndef G_DISABLE_ASSERT + /* + * Tracks the structure of the hash table, not its contents: is only + * incremented when a node is added or removed (is not incremented + * when the key or data of a node is modified). + */ + int version; +#endif + GDestroyNotify key_destroy_func; + GDestroyNotify value_destroy_func; +}; + +typedef struct +{ + GHashTable *hash_table; + gpointer dummy1; + gpointer dummy2; + int position; + gboolean dummy3; + int version; +} RealIter; + +/* Each table size has an associated prime modulo (the first prime + * lower than the table size) used to find the initial bucket. Probing + * then works modulo 2^n. The prime modulo is necessary to get a + * good distribution with poor hash functions. */ +static const gint prime_mod [] = +{ + 1, /* For 1 << 0 */ + 2, + 3, + 7, + 13, + 31, + 61, + 127, + 251, + 509, + 1021, + 2039, + 4093, + 8191, + 16381, + 32749, + 65521, /* For 1 << 16 */ + 131071, + 262139, + 524287, + 1048573, + 2097143, + 4194301, + 8388593, + 16777213, + 33554393, + 67108859, + 134217689, + 268435399, + 536870909, + 1073741789, + 2147483647 /* For 1 << 31 */ +}; + +static void +g_hash_table_set_shift (GHashTable *hash_table, gint shift) +{ + gint i; + guint mask = 0; + + hash_table->size = 1 << shift; + hash_table->mod = prime_mod [shift]; + + for (i = 0; i < shift; i++) + { + mask <<= 1; + mask |= 1; + } + + hash_table->mask = mask; +} + +static gint +g_hash_table_find_closest_shift (gint n) +{ + gint i; + + for (i = 0; n; i++) + n >>= 1; + + return i; +} + +static void +g_hash_table_set_shift_from_size (GHashTable *hash_table, gint size) +{ + gint shift; + + shift = g_hash_table_find_closest_shift (size); + shift = MAX (shift, HASH_TABLE_MIN_SHIFT); + + g_hash_table_set_shift (hash_table, shift); +} + +/* + * g_hash_table_lookup_node: + * @hash_table: our #GHashTable + * @key: the key to lookup against + * @hash_return: optional key hash return location + * Return value: index of the described #GHashNode + * + * Performs a lookup in the hash table. Virtually all hash operations + * will use this function internally. + * + * This function first computes the hash value of the key using the + * user's hash function. + * + * If an entry in the table matching @key is found then this function + * returns the index of that entry in the table, and if not, the + * index of an empty node (never a tombstone). + */ +static inline guint +g_hash_table_lookup_node (GHashTable *hash_table, + gconstpointer key) +{ + GHashNode *node; + guint node_index; + guint hash_value; + guint step = 0; + + /* Empty buckets have hash_value set to 0, and for tombstones, it's 1. + * We need to make sure our hash value is not one of these. */ + + hash_value = (* hash_table->hash_func) (key); + if (G_UNLIKELY (hash_value <= 1)) + hash_value = 2; + + node_index = hash_value % hash_table->mod; + node = &hash_table->nodes [node_index]; + + while (node->key_hash) + { + /* We first check if our full hash values + * are equal so we can avoid calling the full-blown + * key equality function in most cases. + */ + + if (node->key_hash == hash_value) + { + if (hash_table->key_equal_func) + { + if (hash_table->key_equal_func (node->key, key)) + break; + } + else if (node->key == key) + { + break; + } + } + + step++; + node_index += step; + node_index &= hash_table->mask; + node = &hash_table->nodes [node_index]; + } + + return node_index; +} + +/* + * g_hash_table_lookup_node_for_insertion: + * @hash_table: our #GHashTable + * @key: the key to lookup against + * @hash_return: key hash return location + * Return value: index of the described #GHashNode + * + * Performs a lookup in the hash table, preserving extra information + * usually needed for insertion. + * + * This function first computes the hash value of the key using the + * user's hash function. + * + * If an entry in the table matching @key is found then this function + * returns the index of that entry in the table, and if not, the + * index of an unused node (empty or tombstone) where the key can be + * inserted. + * + * The computed hash value is returned in the variable pointed to + * by @hash_return. This is to save insertions from having to compute + * the hash record again for the new record. + */ +static inline guint +g_hash_table_lookup_node_for_insertion (GHashTable *hash_table, + gconstpointer key, + guint *hash_return) +{ + GHashNode *node; + guint node_index; + guint hash_value; + guint first_tombstone; + gboolean have_tombstone = FALSE; + guint step = 0; + + /* Empty buckets have hash_value set to 0, and for tombstones, it's 1. + * We need to make sure our hash value is not one of these. */ + + hash_value = (* hash_table->hash_func) (key); + if (G_UNLIKELY (hash_value <= 1)) + hash_value = 2; + + *hash_return = hash_value; + + node_index = hash_value % hash_table->mod; + node = &hash_table->nodes [node_index]; + + while (node->key_hash) + { + /* We first check if our full hash values + * are equal so we can avoid calling the full-blown + * key equality function in most cases. + */ + + if (node->key_hash == hash_value) + { + if (hash_table->key_equal_func) + { + if (hash_table->key_equal_func (node->key, key)) + return node_index; + } + else if (node->key == key) + { + return node_index; + } + } + else if (node->key_hash == 1 && !have_tombstone) + { + first_tombstone = node_index; + have_tombstone = TRUE; + } + + step++; + node_index += step; + node_index &= hash_table->mask; + node = &hash_table->nodes [node_index]; + } + + if (have_tombstone) + return first_tombstone; + + return node_index; +} + +/* + * g_hash_table_remove_node: + * @hash_table: our #GHashTable + * @node: pointer to node to remove + * @notify: %TRUE if the destroy notify handlers are to be called + * + * Removes a node from the hash table and updates the node count. + * The node is replaced by a tombstone. No table resize is performed. + * + * If @notify is %TRUE then the destroy notify functions are called + * for the key and value of the hash node. + */ +static void +g_hash_table_remove_node (GHashTable *hash_table, + GHashNode *node, + gboolean notify) +{ + if (notify && hash_table->key_destroy_func) + hash_table->key_destroy_func (node->key); + + if (notify && hash_table->value_destroy_func) + hash_table->value_destroy_func (node->value); + + /* Erect tombstone */ + node->key_hash = 1; + + /* Be GC friendly */ + node->key = NULL; + node->value = NULL; + + hash_table->nnodes--; +} + +/* + * g_hash_table_remove_all_nodes: + * @hash_table: our #GHashTable + * @notify: %TRUE if the destroy notify handlers are to be called + * + * Removes all nodes from the table. Since this may be a precursor to + * freeing the table entirely, no resize is performed. + * + * If @notify is %TRUE then the destroy notify functions are called + * for the key and value of the hash node. + */ +static void +g_hash_table_remove_all_nodes (GHashTable *hash_table, + gboolean notify) +{ + int i; + + for (i = 0; i < hash_table->size; i++) + { + GHashNode *node = &hash_table->nodes [i]; + + if (node->key_hash > 1) + { + if (notify && hash_table->key_destroy_func) + hash_table->key_destroy_func (node->key); + + if (notify && hash_table->value_destroy_func) + hash_table->value_destroy_func (node->value); + } + } + + /* We need to set node->key_hash = 0 for all nodes - might as well be GC + * friendly and clear everything */ + memset (hash_table->nodes, 0, hash_table->size * sizeof (GHashNode)); + + hash_table->nnodes = 0; + hash_table->noccupied = 0; +} + +/* + * g_hash_table_resize: + * @hash_table: our #GHashTable + * + * Resizes the hash table to the optimal size based on the number of + * nodes currently held. If you call this function then a resize will + * occur, even if one does not need to occur. Use + * g_hash_table_maybe_resize() instead. + * + * This function may "resize" the hash table to its current size, with + * the side effect of cleaning up tombstones and otherwise optimizing + * the probe sequences. + */ +static void +g_hash_table_resize (GHashTable *hash_table) +{ + GHashNode *new_nodes; + gint old_size; + gint i; + + old_size = hash_table->size; + g_hash_table_set_shift_from_size (hash_table, hash_table->nnodes * 2); + + new_nodes = g_new0 (GHashNode, hash_table->size); + + for (i = 0; i < old_size; i++) + { + GHashNode *node = &hash_table->nodes [i]; + GHashNode *new_node; + guint hash_val; + guint step = 0; + + if (node->key_hash <= 1) + continue; + + hash_val = node->key_hash % hash_table->mod; + new_node = &new_nodes [hash_val]; + + while (new_node->key_hash) + { + step++; + hash_val += step; + hash_val &= hash_table->mask; + new_node = &new_nodes [hash_val]; + } + + *new_node = *node; + } + + g_free (hash_table->nodes); + hash_table->nodes = new_nodes; + hash_table->noccupied = hash_table->nnodes; +} + +/* + * g_hash_table_maybe_resize: + * @hash_table: our #GHashTable + * + * Resizes the hash table, if needed. + * + * Essentially, calls g_hash_table_resize() if the table has strayed + * too far from its ideal size for its number of nodes. + */ +static inline void +g_hash_table_maybe_resize (GHashTable *hash_table) +{ + gint noccupied = hash_table->noccupied; + gint size = hash_table->size; + + if ((size > hash_table->nnodes * 4 && size > 1 << HASH_TABLE_MIN_SHIFT) || + (size <= noccupied + (noccupied / 16))) + g_hash_table_resize (hash_table); +} + +/** + * g_hash_table_new: + * @hash_func: a function to create a hash value from a key. + * Hash values are used to determine where keys are stored within the + * #GHashTable data structure. The g_direct_hash(), g_int_hash(), + * g_int64_hash(), g_double_hash() and g_str_hash() functions are provided + * for some common types of keys. + * If hash_func is %NULL, g_direct_hash() is used. + * @key_equal_func: a function to check two keys for equality. This is + * used when looking up keys in the #GHashTable. The g_direct_equal(), + * g_int_equal(), g_int64_equal(), g_double_equal() and g_str_equal() + * functions are provided for the most common types of keys. + * If @key_equal_func is %NULL, keys are compared directly in a similar + * fashion to g_direct_equal(), but without the overhead of a function call. + * + * Creates a new #GHashTable with a reference count of 1. + * + * Return value: a new #GHashTable. + **/ +GHashTable* +g_hash_table_new (GHashFunc hash_func, + GEqualFunc key_equal_func) +{ + return g_hash_table_new_full (hash_func, key_equal_func, NULL, NULL); +} + + +/** + * g_hash_table_new_full: + * @hash_func: a function to create a hash value from a key. + * @key_equal_func: a function to check two keys for equality. + * @key_destroy_func: a function to free the memory allocated for the key + * used when removing the entry from the #GHashTable or %NULL if you + * don't want to supply such a function. + * @value_destroy_func: a function to free the memory allocated for the + * value used when removing the entry from the #GHashTable or %NULL if + * you don't want to supply such a function. + * + * Creates a new #GHashTable like g_hash_table_new() with a reference count + * of 1 and allows to specify functions to free the memory allocated for the + * key and value that get called when removing the entry from the #GHashTable. + * + * Return value: a new #GHashTable. + **/ +GHashTable* +g_hash_table_new_full (GHashFunc hash_func, + GEqualFunc key_equal_func, + GDestroyNotify key_destroy_func, + GDestroyNotify value_destroy_func) +{ + GHashTable *hash_table; + + hash_table = g_slice_new (GHashTable); + g_hash_table_set_shift (hash_table, HASH_TABLE_MIN_SHIFT); + hash_table->nnodes = 0; + hash_table->noccupied = 0; + hash_table->hash_func = hash_func ? hash_func : g_direct_hash; + hash_table->key_equal_func = key_equal_func; + hash_table->ref_count = 1; +#ifndef G_DISABLE_ASSERT + hash_table->version = 0; +#endif + hash_table->key_destroy_func = key_destroy_func; + hash_table->value_destroy_func = value_destroy_func; + hash_table->nodes = g_new0 (GHashNode, hash_table->size); + + return hash_table; +} + +/** + * g_hash_table_iter_init: + * @iter: an uninitialized #GHashTableIter. + * @hash_table: a #GHashTable. + * + * Initializes a key/value pair iterator and associates it with + * @hash_table. Modifying the hash table after calling this function + * invalidates the returned iterator. + * |[ + * GHashTableIter iter; + * gpointer key, value; + * + * g_hash_table_iter_init (&iter, hash_table); + * while (g_hash_table_iter_next (&iter, &key, &value)) + * { + * /* do something with key and value */ + * } + * ]| + * + * Since: 2.16 + **/ +void +g_hash_table_iter_init (GHashTableIter *iter, + GHashTable *hash_table) +{ + RealIter *ri = (RealIter *) iter; + + g_return_if_fail (iter != NULL); + g_return_if_fail (hash_table != NULL); + + ri->hash_table = hash_table; + ri->position = -1; +#ifndef G_DISABLE_ASSERT + ri->version = hash_table->version; +#endif +} + +/** + * g_hash_table_iter_next: + * @iter: an initialized #GHashTableIter. + * @key: a location to store the key, or %NULL. + * @value: a location to store the value, or %NULL. + * + * Advances @iter and retrieves the key and/or value that are now + * pointed to as a result of this advancement. If %FALSE is returned, + * @key and @value are not set, and the iterator becomes invalid. + * + * Return value: %FALSE if the end of the #GHashTable has been reached. + * + * Since: 2.16 + **/ +gboolean +g_hash_table_iter_next (GHashTableIter *iter, + gpointer *key, + gpointer *value) +{ + RealIter *ri = (RealIter *) iter; + GHashNode *node; + gint position; + + g_return_val_if_fail (iter != NULL, FALSE); +#ifndef G_DISABLE_ASSERT + g_return_val_if_fail (ri->version == ri->hash_table->version, FALSE); +#endif + g_return_val_if_fail (ri->position < ri->hash_table->size, FALSE); + + position = ri->position; + + do + { + position++; + if (position >= ri->hash_table->size) + { + ri->position = position; + return FALSE; + } + + node = &ri->hash_table->nodes [position]; + } + while (node->key_hash <= 1); + + if (key != NULL) + *key = node->key; + if (value != NULL) + *value = node->value; + + ri->position = position; + return TRUE; +} + +/** + * g_hash_table_iter_get_hash_table: + * @iter: an initialized #GHashTableIter. + * + * Returns the #GHashTable associated with @iter. + * + * Return value: the #GHashTable associated with @iter. + * + * Since: 2.16 + **/ +GHashTable * +g_hash_table_iter_get_hash_table (GHashTableIter *iter) +{ + g_return_val_if_fail (iter != NULL, NULL); + + return ((RealIter *) iter)->hash_table; +} + +static void +iter_remove_or_steal (RealIter *ri, gboolean notify) +{ + g_return_if_fail (ri != NULL); +#ifndef G_DISABLE_ASSERT + g_return_if_fail (ri->version == ri->hash_table->version); +#endif + g_return_if_fail (ri->position >= 0); + g_return_if_fail (ri->position < ri->hash_table->size); + + g_hash_table_remove_node (ri->hash_table, &ri->hash_table->nodes [ri->position], notify); + +#ifndef G_DISABLE_ASSERT + ri->version++; + ri->hash_table->version++; +#endif +} + +/** + * g_hash_table_iter_remove: + * @iter: an initialized #GHashTableIter. + * + * Removes the key/value pair currently pointed to by the iterator + * from its associated #GHashTable. Can only be called after + * g_hash_table_iter_next() returned %TRUE, and cannot be called more + * than once for the same key/value pair. + * + * If the #GHashTable was created using g_hash_table_new_full(), the + * key and value are freed using the supplied destroy functions, otherwise + * you have to make sure that any dynamically allocated values are freed + * yourself. + * + * Since: 2.16 + **/ +void +g_hash_table_iter_remove (GHashTableIter *iter) +{ + iter_remove_or_steal ((RealIter *) iter, TRUE); +} + +/** + * g_hash_table_iter_steal: + * @iter: an initialized #GHashTableIter. + * + * Removes the key/value pair currently pointed to by the iterator + * from its associated #GHashTable, without calling the key and value + * destroy functions. Can only be called after + * g_hash_table_iter_next() returned %TRUE, and cannot be called more + * than once for the same key/value pair. + * + * Since: 2.16 + **/ +void +g_hash_table_iter_steal (GHashTableIter *iter) +{ + iter_remove_or_steal ((RealIter *) iter, FALSE); +} + + +/** + * g_hash_table_ref: + * @hash_table: a valid #GHashTable. + * + * Atomically increments the reference count of @hash_table by one. + * This function is MT-safe and may be called from any thread. + * + * Return value: the passed in #GHashTable. + * + * Since: 2.10 + **/ +GHashTable* +g_hash_table_ref (GHashTable *hash_table) +{ + g_return_val_if_fail (hash_table != NULL, NULL); + g_return_val_if_fail (hash_table->ref_count > 0, hash_table); + + g_atomic_int_add (&hash_table->ref_count, 1); + return hash_table; +} + +/** + * g_hash_table_unref: + * @hash_table: a valid #GHashTable. + * + * Atomically decrements the reference count of @hash_table by one. + * If the reference count drops to 0, all keys and values will be + * destroyed, and all memory allocated by the hash table is released. + * This function is MT-safe and may be called from any thread. + * + * Since: 2.10 + **/ +void +g_hash_table_unref (GHashTable *hash_table) +{ + g_return_if_fail (hash_table != NULL); + g_return_if_fail (hash_table->ref_count > 0); + + if (g_atomic_int_exchange_and_add (&hash_table->ref_count, -1) - 1 == 0) + { + g_hash_table_remove_all_nodes (hash_table, TRUE); + g_free (hash_table->nodes); + g_slice_free (GHashTable, hash_table); + } +} + +/** + * g_hash_table_destroy: + * @hash_table: a #GHashTable. + * + * Destroys all keys and values in the #GHashTable and decrements its + * reference count by 1. If keys and/or values are dynamically allocated, + * you should either free them first or create the #GHashTable with destroy + * notifiers using g_hash_table_new_full(). In the latter case the destroy + * functions you supplied will be called on all keys and values during the + * destruction phase. + **/ +void +g_hash_table_destroy (GHashTable *hash_table) +{ + g_return_if_fail (hash_table != NULL); + g_return_if_fail (hash_table->ref_count > 0); + + g_hash_table_remove_all (hash_table); + g_hash_table_unref (hash_table); +} + +/** + * g_hash_table_lookup: + * @hash_table: a #GHashTable. + * @key: the key to look up. + * + * Looks up a key in a #GHashTable. Note that this function cannot + * distinguish between a key that is not present and one which is present + * and has the value %NULL. If you need this distinction, use + * g_hash_table_lookup_extended(). + * + * Return value: the associated value, or %NULL if the key is not found. + **/ +gpointer +g_hash_table_lookup (GHashTable *hash_table, + gconstpointer key) +{ + GHashNode *node; + guint node_index; + + g_return_val_if_fail (hash_table != NULL, NULL); + + node_index = g_hash_table_lookup_node (hash_table, key); + node = &hash_table->nodes [node_index]; + + return node->key_hash ? node->value : NULL; +} + +/** + * g_hash_table_lookup_extended: + * @hash_table: a #GHashTable + * @lookup_key: the key to look up + * @orig_key: return location for the original key, or %NULL + * @value: return location for the value associated with the key, or %NULL + * + * Looks up a key in the #GHashTable, returning the original key and the + * associated value and a #gboolean which is %TRUE if the key was found. This + * is useful if you need to free the memory allocated for the original key, + * for example before calling g_hash_table_remove(). + * + * You can actually pass %NULL for @lookup_key to test + * whether the %NULL key exists. + * + * Return value: %TRUE if the key was found in the #GHashTable. + **/ +gboolean +g_hash_table_lookup_extended (GHashTable *hash_table, + gconstpointer lookup_key, + gpointer *orig_key, + gpointer *value) +{ + GHashNode *node; + guint node_index; + + g_return_val_if_fail (hash_table != NULL, FALSE); + + node_index = g_hash_table_lookup_node (hash_table, lookup_key); + node = &hash_table->nodes [node_index]; + + if (!node->key_hash) + return FALSE; + + if (orig_key) + *orig_key = node->key; + + if (value) + *value = node->value; + + return TRUE; +} + +/* + * g_hash_table_insert_internal: + * @hash_table: our #GHashTable + * @key: the key to insert + * @value: the value to insert + * @keep_new_key: if %TRUE and this key already exists in the table + * then call the destroy notify function on the old key. If %FALSE + * then call the destroy notify function on the new key. + * + * Implements the common logic for the g_hash_table_insert() and + * g_hash_table_replace() functions. + * + * Do a lookup of @key. If it is found, replace it with the new + * @value (and perhaps the new @key). If it is not found, create a + * new node. + */ +static void +g_hash_table_insert_internal (GHashTable *hash_table, + gpointer key, + gpointer value, + gboolean keep_new_key) +{ + GHashNode *node; + guint node_index; + guint key_hash; + guint old_hash; + + g_return_if_fail (hash_table != NULL); + g_return_if_fail (hash_table->ref_count > 0); + + node_index = g_hash_table_lookup_node_for_insertion (hash_table, key, &key_hash); + node = &hash_table->nodes [node_index]; + + old_hash = node->key_hash; + + if (old_hash > 1) + { + if (keep_new_key) + { + if (hash_table->key_destroy_func) + hash_table->key_destroy_func (node->key); + node->key = key; + } + else + { + if (hash_table->key_destroy_func) + hash_table->key_destroy_func (key); + } + + if (hash_table->value_destroy_func) + hash_table->value_destroy_func (node->value); + + node->value = value; + } + else + { + node->key = key; + node->value = value; + node->key_hash = key_hash; + + hash_table->nnodes++; + + if (old_hash == 0) + { + /* We replaced an empty node, and not a tombstone */ + hash_table->noccupied++; + g_hash_table_maybe_resize (hash_table); + } + +#ifndef G_DISABLE_ASSERT + hash_table->version++; +#endif + } +} + +/** + * g_hash_table_insert: + * @hash_table: a #GHashTable. + * @key: a key to insert. + * @value: the value to associate with the key. + * + * Inserts a new key and value into a #GHashTable. + * + * If the key already exists in the #GHashTable its current value is replaced + * with the new value. If you supplied a @value_destroy_func when creating the + * #GHashTable, the old value is freed using that function. If you supplied + * a @key_destroy_func when creating the #GHashTable, the passed key is freed + * using that function. + **/ +void +g_hash_table_insert (GHashTable *hash_table, + gpointer key, + gpointer value) +{ + g_hash_table_insert_internal (hash_table, key, value, FALSE); +} + +/** + * g_hash_table_replace: + * @hash_table: a #GHashTable. + * @key: a key to insert. + * @value: the value to associate with the key. + * + * Inserts a new key and value into a #GHashTable similar to + * g_hash_table_insert(). The difference is that if the key already exists + * in the #GHashTable, it gets replaced by the new key. If you supplied a + * @value_destroy_func when creating the #GHashTable, the old value is freed + * using that function. If you supplied a @key_destroy_func when creating the + * #GHashTable, the old key is freed using that function. + **/ +void +g_hash_table_replace (GHashTable *hash_table, + gpointer key, + gpointer value) +{ + g_hash_table_insert_internal (hash_table, key, value, TRUE); +} + +/* + * g_hash_table_remove_internal: + * @hash_table: our #GHashTable + * @key: the key to remove + * @notify: %TRUE if the destroy notify handlers are to be called + * Return value: %TRUE if a node was found and removed, else %FALSE + * + * Implements the common logic for the g_hash_table_remove() and + * g_hash_table_steal() functions. + * + * Do a lookup of @key and remove it if it is found, calling the + * destroy notify handlers only if @notify is %TRUE. + */ +static gboolean +g_hash_table_remove_internal (GHashTable *hash_table, + gconstpointer key, + gboolean notify) +{ + GHashNode *node; + guint node_index; + + g_return_val_if_fail (hash_table != NULL, FALSE); + + node_index = g_hash_table_lookup_node (hash_table, key); + node = &hash_table->nodes [node_index]; + + /* g_hash_table_lookup_node() never returns a tombstone, so this is safe */ + if (!node->key_hash) + return FALSE; + + g_hash_table_remove_node (hash_table, node, notify); + g_hash_table_maybe_resize (hash_table); + +#ifndef G_DISABLE_ASSERT + hash_table->version++; +#endif + + return TRUE; +} + +/** + * g_hash_table_remove: + * @hash_table: a #GHashTable. + * @key: the key to remove. + * + * Removes a key and its associated value from a #GHashTable. + * + * If the #GHashTable was created using g_hash_table_new_full(), the + * key and value are freed using the supplied destroy functions, otherwise + * you have to make sure that any dynamically allocated values are freed + * yourself. + * + * Return value: %TRUE if the key was found and removed from the #GHashTable. + **/ +gboolean +g_hash_table_remove (GHashTable *hash_table, + gconstpointer key) +{ + return g_hash_table_remove_internal (hash_table, key, TRUE); +} + +/** + * g_hash_table_steal: + * @hash_table: a #GHashTable. + * @key: the key to remove. + * + * Removes a key and its associated value from a #GHashTable without + * calling the key and value destroy functions. + * + * Return value: %TRUE if the key was found and removed from the #GHashTable. + **/ +gboolean +g_hash_table_steal (GHashTable *hash_table, + gconstpointer key) +{ + return g_hash_table_remove_internal (hash_table, key, FALSE); +} + +/** + * g_hash_table_remove_all: + * @hash_table: a #GHashTable + * + * Removes all keys and their associated values from a #GHashTable. + * + * If the #GHashTable was created using g_hash_table_new_full(), the keys + * and values are freed using the supplied destroy functions, otherwise you + * have to make sure that any dynamically allocated values are freed + * yourself. + * + * Since: 2.12 + **/ +void +g_hash_table_remove_all (GHashTable *hash_table) +{ + g_return_if_fail (hash_table != NULL); + +#ifndef G_DISABLE_ASSERT + if (hash_table->nnodes != 0) + hash_table->version++; +#endif + + g_hash_table_remove_all_nodes (hash_table, TRUE); + g_hash_table_maybe_resize (hash_table); +} + +/** + * g_hash_table_steal_all: + * @hash_table: a #GHashTable. + * + * Removes all keys and their associated values from a #GHashTable + * without calling the key and value destroy functions. + * + * Since: 2.12 + **/ +void +g_hash_table_steal_all (GHashTable *hash_table) +{ + g_return_if_fail (hash_table != NULL); + +#ifndef G_DISABLE_ASSERT + if (hash_table->nnodes != 0) + hash_table->version++; +#endif + + g_hash_table_remove_all_nodes (hash_table, FALSE); + g_hash_table_maybe_resize (hash_table); +} + +/* + * g_hash_table_foreach_remove_or_steal: + * @hash_table: our #GHashTable + * @func: the user's callback function + * @user_data: data for @func + * @notify: %TRUE if the destroy notify handlers are to be called + * + * Implements the common logic for g_hash_table_foreach_remove() and + * g_hash_table_foreach_steal(). + * + * Iterates over every node in the table, calling @func with the key + * and value of the node (and @user_data). If @func returns %TRUE the + * node is removed from the table. + * + * If @notify is true then the destroy notify handlers will be called + * for each removed node. + */ +static guint +g_hash_table_foreach_remove_or_steal (GHashTable *hash_table, + GHRFunc func, + gpointer user_data, + gboolean notify) +{ + guint deleted = 0; + gint i; + + for (i = 0; i < hash_table->size; i++) + { + GHashNode *node = &hash_table->nodes [i]; + + if (node->key_hash > 1 && (* func) (node->key, node->value, user_data)) + { + g_hash_table_remove_node (hash_table, node, notify); + deleted++; + } + } + + g_hash_table_maybe_resize (hash_table); + +#ifndef G_DISABLE_ASSERT + if (deleted > 0) + hash_table->version++; +#endif + + return deleted; +} + +/** + * g_hash_table_foreach_remove: + * @hash_table: a #GHashTable. + * @func: the function to call for each key/value pair. + * @user_data: user data to pass to the function. + * + * Calls the given function for each key/value pair in the #GHashTable. + * If the function returns %TRUE, then the key/value pair is removed from the + * #GHashTable. If you supplied key or value destroy functions when creating + * the #GHashTable, they are used to free the memory allocated for the removed + * keys and values. + * + * See #GHashTableIter for an alternative way to loop over the + * key/value pairs in the hash table. + * + * Return value: the number of key/value pairs removed. + **/ +guint +g_hash_table_foreach_remove (GHashTable *hash_table, + GHRFunc func, + gpointer user_data) +{ + g_return_val_if_fail (hash_table != NULL, 0); + g_return_val_if_fail (func != NULL, 0); + + return g_hash_table_foreach_remove_or_steal (hash_table, func, user_data, TRUE); +} + +/** + * g_hash_table_foreach_steal: + * @hash_table: a #GHashTable. + * @func: the function to call for each key/value pair. + * @user_data: user data to pass to the function. + * + * Calls the given function for each key/value pair in the #GHashTable. + * If the function returns %TRUE, then the key/value pair is removed from the + * #GHashTable, but no key or value destroy functions are called. + * + * See #GHashTableIter for an alternative way to loop over the + * key/value pairs in the hash table. + * + * Return value: the number of key/value pairs removed. + **/ +guint +g_hash_table_foreach_steal (GHashTable *hash_table, + GHRFunc func, + gpointer user_data) +{ + g_return_val_if_fail (hash_table != NULL, 0); + g_return_val_if_fail (func != NULL, 0); + + return g_hash_table_foreach_remove_or_steal (hash_table, func, user_data, FALSE); +} + +/** + * g_hash_table_foreach: + * @hash_table: a #GHashTable. + * @func: the function to call for each key/value pair. + * @user_data: user data to pass to the function. + * + * Calls the given function for each of the key/value pairs in the + * #GHashTable. The function is passed the key and value of each + * pair, and the given @user_data parameter. The hash table may not + * be modified while iterating over it (you can't add/remove + * items). To remove all items matching a predicate, use + * g_hash_table_foreach_remove(). + * + * See g_hash_table_find() for performance caveats for linear + * order searches in contrast to g_hash_table_lookup(). + **/ +void +g_hash_table_foreach (GHashTable *hash_table, + GHFunc func, + gpointer user_data) +{ + gint i; + + g_return_if_fail (hash_table != NULL); + g_return_if_fail (func != NULL); + + for (i = 0; i < hash_table->size; i++) + { + GHashNode *node = &hash_table->nodes [i]; + + if (node->key_hash > 1) + (* func) (node->key, node->value, user_data); + } +} + +/** + * g_hash_table_find: + * @hash_table: a #GHashTable. + * @predicate: function to test the key/value pairs for a certain property. + * @user_data: user data to pass to the function. + * + * Calls the given function for key/value pairs in the #GHashTable until + * @predicate returns %TRUE. The function is passed the key and value of + * each pair, and the given @user_data parameter. The hash table may not + * be modified while iterating over it (you can't add/remove items). + * + * Note, that hash tables are really only optimized for forward lookups, + * i.e. g_hash_table_lookup(). + * So code that frequently issues g_hash_table_find() or + * g_hash_table_foreach() (e.g. in the order of once per every entry in a + * hash table) should probably be reworked to use additional or different + * data structures for reverse lookups (keep in mind that an O(n) find/foreach + * operation issued for all n values in a hash table ends up needing O(n*n) + * operations). + * + * Return value: The value of the first key/value pair is returned, for which + * func evaluates to %TRUE. If no pair with the requested property is found, + * %NULL is returned. + * + * Since: 2.4 + **/ +gpointer +g_hash_table_find (GHashTable *hash_table, + GHRFunc predicate, + gpointer user_data) +{ + gint i; + + g_return_val_if_fail (hash_table != NULL, NULL); + g_return_val_if_fail (predicate != NULL, NULL); + + for (i = 0; i < hash_table->size; i++) + { + GHashNode *node = &hash_table->nodes [i]; + + if (node->key_hash > 1 && predicate (node->key, node->value, user_data)) + return node->value; + } + + return NULL; +} + +/** + * g_hash_table_size: + * @hash_table: a #GHashTable. + * + * Returns the number of elements contained in the #GHashTable. + * + * Return value: the number of key/value pairs in the #GHashTable. + **/ +guint +g_hash_table_size (GHashTable *hash_table) +{ + g_return_val_if_fail (hash_table != NULL, 0); + + return hash_table->nnodes; +} + +/** + * g_hash_table_get_keys: + * @hash_table: a #GHashTable + * + * Retrieves every key inside @hash_table. The returned data is valid + * until @hash_table is modified. + * + * Return value: a #GList containing all the keys inside the hash + * table. The content of the list is owned by the hash table and + * should not be modified or freed. Use g_list_free() when done + * using the list. + * + * Since: 2.14 + */ +GList * +g_hash_table_get_keys (GHashTable *hash_table) +{ + gint i; + GList *retval; + + g_return_val_if_fail (hash_table != NULL, NULL); + + retval = NULL; + for (i = 0; i < hash_table->size; i++) + { + GHashNode *node = &hash_table->nodes [i]; + + if (node->key_hash > 1) + retval = g_list_prepend (retval, node->key); + } + + return retval; +} + +/** + * g_hash_table_get_values: + * @hash_table: a #GHashTable + * + * Retrieves every value inside @hash_table. The returned data is + * valid until @hash_table is modified. + * + * Return value: a #GList containing all the values inside the hash + * table. The content of the list is owned by the hash table and + * should not be modified or freed. Use g_list_free() when done + * using the list. + * + * Since: 2.14 + */ +GList * +g_hash_table_get_values (GHashTable *hash_table) +{ + gint i; + GList *retval; + + g_return_val_if_fail (hash_table != NULL, NULL); + + retval = NULL; + for (i = 0; i < hash_table->size; i++) + { + GHashNode *node = &hash_table->nodes [i]; + + if (node->key_hash > 1) + retval = g_list_prepend (retval, node->value); + } + + return retval; +} |