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glib/glib/ghash.c
Simon McVittie f778564ba2 Be clear that g_str_hash etc. don't accept NULL 
This covers the str, double, int, int64 hash and equal functions, but not
anything that takes an "object", since the convention is that "object
methods" never accept NULL anyway.

Bug: https://bugzilla.gnome.org/show_bug.cgi?id=592715
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Colin Walters <walters@verbum.org>
2011-10-04 09:48:35 +01:00

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/* 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 "gstrfuncs.h"
#include "gatomic.h"
#include "gtestutils.h"
#include "gslice.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().
*
* g_hash_table_lookup_extended() can also be used to simply
* check if a key is present in the hash table.
*
* 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().
*
* <example>
* <title>Using a GHashTable as a set</title>
* <para>
* A common use-case for hash tables is to store information about
* a set of keys, without associating any particular value with each
* key. GHashTable optimizes one way of doing so: If you store only
* key-value pairs where key == value, then GHashTable does not
* allocate memory to store the values, which can be a considerable
* space saving, if your set is large.
* </para>
* <programlisting>
* GHashTable *
* set_new (GHashFunc hash_func,
* GEqualFunc equal_func,
* GDestroyNotify destroy)
* {
* return g_hash_table_new_full (hash_func, equal_func, destroy, NULL);
* }
*
* void
* set_insert (GHashTable *set,
* gpointer element)
* {
* g_hash_table_insert (set, element, element);
* }
*
* gboolean
* set_contains (GHashTable *set,
* gpointer element)
* {
* return g_hash_table_lookup_extended (set, element, NULL, NULL);
* }
*
* gboolean
* set_remove (GHashTable *set,
* gpointer element)
* {
* return g_hash_table_remove (set, element);
* }
* </programlisting>
* </example>
*/
/**
* 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
*
* 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.
*
* g_direct_hash() is also the appropriate hash function for keys
* of the form <literal>GINT_TO_POINTER (n)</literal> (or similar macros).
*
* <!-- 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.
*
* Returns: the hash value corresponding to the key
*/
/**
* 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()
*
* 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.
*
* Returns: %TRUE if the key/value pair should be removed from the
* #GHashTable
*/
/**
* GEqualFunc:
* @a: a value
* @b: a value to compare with
*
* 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.
*
* Returns: %TRUE if @a = @b; %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().
*/
/**
* g_hash_table_freeze:
* @hash_table: a #GHashTable
*
* This function is deprecated and will be removed in the next major
* release of GLib. It does nothing.
*/
/**
* g_hash_table_thaw:
* @hash_table: a #GHashTable
*
* This function is deprecated and will be removed in the next major
* release of GLib. It does nothing.
*/
#define HASH_TABLE_MIN_SHIFT 3 /* 1 << 3 == 8 buckets */
#define UNUSED_HASH_VALUE 0
#define TOMBSTONE_HASH_VALUE 1
#define HASH_IS_UNUSED(h_) ((h_) == UNUSED_HASH_VALUE)
#define HASH_IS_TOMBSTONE(h_) ((h_) == TOMBSTONE_HASH_VALUE)
#define HASH_IS_REAL(h_) ((h_) >= 2)
struct _GHashTable
{
gint size;
gint mod;
guint mask;
gint nnodes;
gint noccupied; /* nnodes + tombstones */
gpointer *keys;
guint *hashes;
gpointer *values;
GHashFunc hash_func;
GEqualFunc key_equal_func;
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: key hash return location
*
* 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.
*
* Returns: index of the described node
*/
static inline guint
g_hash_table_lookup_node (GHashTable *hash_table,
gconstpointer key,
guint *hash_return)
{
guint node_index;
guint node_hash;
guint hash_value;
guint first_tombstone = 0;
gboolean have_tombstone = FALSE;
guint step = 0;
hash_value = hash_table->hash_func (key);
if (G_UNLIKELY (!HASH_IS_REAL (hash_value)))
hash_value = 2;
*hash_return = hash_value;
node_index = hash_value % hash_table->mod;
node_hash = hash_table->hashes[node_index];
while (!HASH_IS_UNUSED (node_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_hash == hash_value)
{
gpointer node_key = hash_table->keys[node_index];
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 (HASH_IS_TOMBSTONE (node_hash) && !have_tombstone)
{
first_tombstone = node_index;
have_tombstone = TRUE;
}
step++;
node_index += step;
node_index &= hash_table->mask;
node_hash = hash_table->hashes[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,
gint i,
gboolean notify)
{
gpointer key;
gpointer value;
key = hash_table->keys[i];
value = hash_table->values[i];
/* Erect tombstone */
hash_table->hashes[i] = TOMBSTONE_HASH_VALUE;
/* Be GC friendly */
hash_table->keys[i] = NULL;
hash_table->values[i] = NULL;
hash_table->nnodes--;
if (notify && hash_table->key_destroy_func)
hash_table->key_destroy_func (key);
if (notify && hash_table->value_destroy_func)
hash_table->value_destroy_func (value);
}
/*
* 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;
gpointer key;
gpointer value;
hash_table->nnodes = 0;
hash_table->noccupied = 0;
if (!notify ||
(hash_table->key_destroy_func == NULL &&
hash_table->value_destroy_func == NULL))
{
memset (hash_table->hashes, 0, hash_table->size * sizeof (guint));
memset (hash_table->keys, 0, hash_table->size * sizeof (gpointer));
memset (hash_table->values, 0, hash_table->size * sizeof (gpointer));
return;
}
for (i = 0; i < hash_table->size; i++)
{
if (HASH_IS_REAL (hash_table->hashes[i]))
{
key = hash_table->keys[i];
value = hash_table->values[i];
hash_table->hashes[i] = UNUSED_HASH_VALUE;
hash_table->keys[i] = NULL;
hash_table->values[i] = NULL;
if (hash_table->key_destroy_func != NULL)
hash_table->key_destroy_func (key);
if (hash_table->value_destroy_func != NULL)
hash_table->value_destroy_func (value);
}
else if (HASH_IS_TOMBSTONE (hash_table->hashes[i]))
{
hash_table->hashes[i] = UNUSED_HASH_VALUE;
}
}
}
/*
* 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)
{
gpointer *new_keys;
gpointer *new_values;
guint *new_hashes;
gint old_size;
gint i;
old_size = hash_table->size;
g_hash_table_set_shift_from_size (hash_table, hash_table->nnodes * 2);
new_keys = g_new0 (gpointer, hash_table->size);
if (hash_table->keys == hash_table->values)
new_values = new_keys;
else
new_values = g_new0 (gpointer, hash_table->size);
new_hashes = g_new0 (guint, hash_table->size);
for (i = 0; i < old_size; i++)
{
guint node_hash = hash_table->hashes[i];
guint hash_val;
guint step = 0;
if (!HASH_IS_REAL (node_hash))
continue;
hash_val = node_hash % hash_table->mod;
while (!HASH_IS_UNUSED (new_hashes[hash_val]))
{
step++;
hash_val += step;
hash_val &= hash_table->mask;
}
new_hashes[hash_val] = hash_table->hashes[i];
new_keys[hash_val] = hash_table->keys[i];
new_values[hash_val] = hash_table->values[i];
}
if (hash_table->keys != hash_table->values)
g_free (hash_table->values);
g_free (hash_table->keys);
g_free (hash_table->hashes);
hash_table->keys = new_keys;
hash_table->values = new_values;
hash_table->hashes = new_hashes;
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
* @key_equal_func: a function to check two keys for equality
*
* Creates a new #GHashTable with a reference count of 1.
*
* Hash values returned by @hash_func 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 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.
*
* 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->keys = g_new0 (gpointer, hash_table->size);
hash_table->values = hash_table->keys;
hash_table->hashes = g_new0 (guint, 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))
* {
* /&ast; do something with key and value &ast;/
* }
* ]|
*
* 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;
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;
}
}
while (!HASH_IS_REAL (ri->hash_table->hashes[position]));
if (key != NULL)
*key = ri->hash_table->keys[position];
if (value != NULL)
*value = ri->hash_table->values[position];
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->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_insert_node:
* @hash_table: our #GHashTable
* @node_index: pointer to node to insert/replace
* @key_hash: key hash
* @key: key to replace with
* @value: value to replace with
*
* Inserts a value at @node_index in the hash table and updates it.
*/
static void
g_hash_table_insert_node (GHashTable *hash_table,
guint node_index,
guint key_hash,
gpointer key,
gpointer value,
gboolean keep_new_key)
{
guint old_hash;
gpointer old_key;
gpointer old_value;
if (G_UNLIKELY (hash_table->keys == hash_table->values && key != value))
hash_table->values = g_memdup (hash_table->keys, sizeof (gpointer) * hash_table->size);
old_hash = hash_table->hashes[node_index];
old_key = hash_table->keys[node_index];
old_value = hash_table->values[node_index];
if (HASH_IS_REAL (old_hash))
{
if (keep_new_key)
hash_table->keys[node_index] = key;
hash_table->values[node_index] = value;
}
else
{
hash_table->keys[node_index] = key;
hash_table->values[node_index] = value;
hash_table->hashes[node_index] = key_hash;
hash_table->nnodes++;
if (HASH_IS_UNUSED (old_hash))
{
/* 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
}
if (HASH_IS_REAL (old_hash))
{
if (hash_table->key_destroy_func)
hash_table->key_destroy_func (keep_new_key ? old_key : key);
if (hash_table->value_destroy_func)
hash_table->value_destroy_func (old_value);
}
}
/**
* g_hash_table_iter_replace:
* @iter: an initialized #GHashTableIter
* @value: the value to replace with
*
* Replaces the value currently pointed to by the iterator
* from its associated #GHashTable. Can only be called after
* g_hash_table_iter_next() returned %TRUE.
*
* If you supplied a @value_destroy_func when creating the
* #GHashTable, the old value is freed using that function.
*
* Since: 2.30
*/
void
g_hash_table_iter_replace (GHashTableIter *iter,
gpointer value)
{
RealIter *ri;
guint node_hash;
gpointer key;
ri = (RealIter *) iter;
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);
node_hash = ri->hash_table->hashes[ri->position];
key = ri->hash_table->keys[ri->position];
g_hash_table_insert_node (ri->hash_table, ri->position, node_hash, key, value, TRUE);
#ifndef G_DISABLE_ASSERT
ri->version++;
ri->hash_table->version++;
#endif
}
/**
* 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_atomic_int_inc (&hash_table->ref_count);
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);
if (g_atomic_int_dec_and_test (&hash_table->ref_count))
{
g_hash_table_remove_all_nodes (hash_table, TRUE);
if (hash_table->keys != hash_table->values)
g_free (hash_table->values);
g_free (hash_table->keys);
g_free (hash_table->hashes);
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_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)
{
guint node_index;
guint node_hash;
g_return_val_if_fail (hash_table != NULL, NULL);
node_index = g_hash_table_lookup_node (hash_table, key, &node_hash);
return HASH_IS_REAL (hash_table->hashes[node_index])
? hash_table->values[node_index]
: 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, provided the hash and equal functions
* of @hash_table are %NULL-safe.
*
* 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)
{
guint node_index;
guint node_hash;
g_return_val_if_fail (hash_table != NULL, FALSE);
node_index = g_hash_table_lookup_node (hash_table, lookup_key, &node_hash);
if (!HASH_IS_REAL (hash_table->hashes[node_index]))
return FALSE;
if (orig_key)
*orig_key = hash_table->keys[node_index];
if (value)
*value = hash_table->values[node_index];
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)
{
guint key_hash;
guint node_index;
g_return_if_fail (hash_table != NULL);
node_index = g_hash_table_lookup_node (hash_table, key, &key_hash);
g_hash_table_insert_node (hash_table, node_index, key_hash, key, value, keep_new_key);
}
/**
* 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)
{
guint node_index;
guint node_hash;
g_return_val_if_fail (hash_table != NULL, FALSE);
node_index = g_hash_table_lookup_node (hash_table, key, &node_hash);
if (!HASH_IS_REAL (hash_table->hashes[node_index]))
return FALSE;
g_hash_table_remove_node (hash_table, node_index, 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.
*
* Returns: %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.
*
* Returns: %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: a #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;
#ifndef G_DISABLE_ASSERT
gint version = hash_table->version;
#endif
for (i = 0; i < hash_table->size; i++)
{
guint node_hash = hash_table->hashes[i];
gpointer node_key = hash_table->keys[i];
gpointer node_value = hash_table->values[i];
if (HASH_IS_REAL (node_hash) &&
(* func) (node_key, node_value, user_data))
{
g_hash_table_remove_node (hash_table, i, notify);
deleted++;
}
#ifndef G_DISABLE_ASSERT
g_return_val_if_fail (version == hash_table->version, 0);
#endif
}
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;
#ifndef G_DISABLE_ASSERT
gint version = hash_table->version;
#endif
g_return_if_fail (hash_table != NULL);
g_return_if_fail (func != NULL);
for (i = 0; i < hash_table->size; i++)
{
guint node_hash = hash_table->hashes[i];
gpointer node_key = hash_table->keys[i];
gpointer node_value = hash_table->values[i];
if (HASH_IS_REAL (node_hash))
(* func) (node_key, node_value, user_data);
#ifndef G_DISABLE_ASSERT
g_return_if_fail (version == hash_table->version);
#endif
}
}
/**
* 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 @predicate 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;
#ifndef G_DISABLE_ASSERT
gint version = hash_table->version;
#endif
gboolean match;
g_return_val_if_fail (hash_table != NULL, NULL);
g_return_val_if_fail (predicate != NULL, NULL);
match = FALSE;
for (i = 0; i < hash_table->size; i++)
{
guint node_hash = hash_table->hashes[i];
gpointer node_key = hash_table->keys[i];
gpointer node_value = hash_table->values[i];
if (HASH_IS_REAL (node_hash))
match = predicate (node_key, node_value, user_data);
#ifndef G_DISABLE_ASSERT
g_return_val_if_fail (version == hash_table->version, NULL);
#endif
if (match)
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++)
{
if (HASH_IS_REAL (hash_table->hashes[i]))
retval = g_list_prepend (retval, hash_table->keys[i]);
}
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++)
{
if (HASH_IS_REAL (hash_table->hashes[i]))
retval = g_list_prepend (retval, hash_table->values[i]);
}
return retval;
}
/* Hash functions.
*/
/**
* g_str_equal:
* @v1: a key
* @v2: a key to compare with @v1
*
* Compares two strings for byte-by-byte equality and returns %TRUE
* if they are equal. It can be passed to g_hash_table_new() as the
* @key_equal_func parameter, when using non-%NULL strings as keys in a
* #GHashTable.
*
* Note that this function is primarily meant as a hash table comparison
* function. For a general-purpose, %NULL-safe string comparison function,
* see g_strcmp0().
*
* Returns: %TRUE if the two keys match
*/
gboolean
g_str_equal (gconstpointer v1,
gconstpointer v2)
{
const gchar *string1 = v1;
const gchar *string2 = v2;
return strcmp (string1, string2) == 0;
}
/**
* g_str_hash:
* @v: a string key
*
* Converts a string to a hash value.
*
* This function implements the widely used "djb" hash apparently posted
* by Daniel Bernstein to comp.lang.c some time ago. The 32 bit
* unsigned hash value starts at 5381 and for each byte 'c' in the
* string, is updated: <literal>hash = hash * 33 + c</literal>. This
* function uses the signed value of each byte.
*
* It can be passed to g_hash_table_new() as the @hash_func parameter,
* when using non-%NULL strings as keys in a #GHashTable.
*
* Returns: a hash value corresponding to the key
*/
guint
g_str_hash (gconstpointer v)
{
const signed char *p;
guint32 h = 5381;
for (p = v; *p != '\0'; p++)
h = (h << 5) + h + *p;
return h;
}
/**
* g_direct_hash:
* @v: (allow-none): a #gpointer key
*
* Converts a gpointer to a hash value.
* It can be passed to g_hash_table_new() as the @hash_func parameter,
* when using opaque pointers compared by pointer value as keys in a
* #GHashTable.
*
* This hash function is also appropriate for keys that are integers stored
* in pointers, such as <literal>GINT_TO_POINTER (n)</literal>.
*
* Returns: a hash value corresponding to the key.
*/
guint
g_direct_hash (gconstpointer v)
{
return GPOINTER_TO_UINT (v);
}
/**
* g_direct_equal:
* @v1: (allow-none): a key
* @v2: (allow-none): a key to compare with @v1
*
* Compares two #gpointer arguments and returns %TRUE if they are equal.
* It can be passed to g_hash_table_new() as the @key_equal_func
* parameter, when using opaque pointers compared by pointer value as keys
* in a #GHashTable.
*
* This equality function is also appropriate for keys that are integers stored
* in pointers, such as <literal>GINT_TO_POINTER (n)</literal>.
*
* Returns: %TRUE if the two keys match.
*/
gboolean
g_direct_equal (gconstpointer v1,
gconstpointer v2)
{
return v1 == v2;
}
/**
* g_int_equal:
* @v1: a pointer to a #gint key
* @v2: a pointer to a #gint key to compare with @v1
*
* Compares the two #gint values being pointed to and returns
* %TRUE if they are equal.
* It can be passed to g_hash_table_new() as the @key_equal_func
* parameter, when using non-%NULL pointers to integers as keys in a
* #GHashTable.
*
* Note that this function acts on pointers to #gint, not on #gint directly:
* if your hash table's keys are of the form
* <literal>GINT_TO_POINTER (n)</literal>, use g_direct_equal() instead.
*
* Returns: %TRUE if the two keys match.
*/
gboolean
g_int_equal (gconstpointer v1,
gconstpointer v2)
{
return *((const gint*) v1) == *((const gint*) v2);
}
/**
* g_int_hash:
* @v: a pointer to a #gint key
*
* Converts a pointer to a #gint to a hash value.
* It can be passed to g_hash_table_new() as the @hash_func parameter,
* when using non-%NULL pointers to integer values as keys in a #GHashTable.
*
* Note that this function acts on pointers to #gint, not on #gint directly:
* if your hash table's keys are of the form
* <literal>GINT_TO_POINTER (n)</literal>, use g_direct_hash() instead.
*
* Returns: a hash value corresponding to the key.
*/
guint
g_int_hash (gconstpointer v)
{
return *(const gint*) v;
}
/**
* g_int64_equal:
* @v1: a pointer to a #gint64 key
* @v2: a pointer to a #gint64 key to compare with @v1
*
* Compares the two #gint64 values being pointed to and returns
* %TRUE if they are equal.
* It can be passed to g_hash_table_new() as the @key_equal_func
* parameter, when using non-%NULL pointers to 64-bit integers as keys in a
* #GHashTable.
*
* Returns: %TRUE if the two keys match.
*
* Since: 2.22
*/
gboolean
g_int64_equal (gconstpointer v1,
gconstpointer v2)
{
return *((const gint64*) v1) == *((const gint64*) v2);
}
/**
* g_int64_hash:
* @v: a pointer to a #gint64 key
*
* Converts a pointer to a #gint64 to a hash value.
*
* It can be passed to g_hash_table_new() as the @hash_func parameter,
* when using non-%NULL pointers to 64-bit integer values as keys in a
* #GHashTable.
*
* Returns: a hash value corresponding to the key.
*
* Since: 2.22
*/
guint
g_int64_hash (gconstpointer v)
{
return (guint) *(const gint64*) v;
}
/**
* g_double_equal:
* @v1: a pointer to a #gdouble key
* @v2: a pointer to a #gdouble key to compare with @v1
*
* Compares the two #gdouble values being pointed to and returns
* %TRUE if they are equal.
* It can be passed to g_hash_table_new() as the @key_equal_func
* parameter, when using non-%NULL pointers to doubles as keys in a
* #GHashTable.
*
* Returns: %TRUE if the two keys match.
*
* Since: 2.22
*/
gboolean
g_double_equal (gconstpointer v1,
gconstpointer v2)
{
return *((const gdouble*) v1) == *((const gdouble*) v2);
}
/**
* g_double_hash:
* @v: a pointer to a #gdouble key
*
* Converts a pointer to a #gdouble to a hash value.
* It can be passed to g_hash_table_new() as the @hash_func parameter,
* It can be passed to g_hash_table_new() as the @hash_func parameter,
* when using non-%NULL pointers to doubles as keys in a #GHashTable.
*
* Returns: a hash value corresponding to the key.
*
* Since: 2.22
*/
guint
g_double_hash (gconstpointer v)
{
return (guint) *(const gdouble*) v;
}
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