glib/ghash.c

/* 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 "glib.h"
#include "galias.h"


#define HASH_TABLE_MIN_SIZE 11
#define HASH_TABLE_MAX_SIZE 13845163


typedef struct _GHashNode      GHashNode;

struct _GHashNode
{
  gpointer   key;
  gpointer   value;
  GHashNode *next;
  guint      key_hash;
};

struct _GHashTable
{
  gint             size;
  gint             nnodes;
  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;
  GHashNode	*prev_node;
  GHashNode	*node;
  int		position;
  gboolean	pre_advanced;
  int		version;
} RealIter;

/*
 * g_hash_table_lookup_node:
 * @hash_table: our #GHashTable
 * @key: the key to lookup against
 * @hash_return: optional key hash return location
 * Return value: a pointer to the described #GHashNode pointer
 *
 * 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 a pointer to the pointer to that entry in the table.  In
 * the case that the entry is at the head of a chain, this pointer
 * will be an item in the nodes[] array.  In the case that the entry
 * is not at the head of a chain, this pointer will be the ->next
 * pointer on the node that preceeds it.
 *
 * In the case that no matching entry exists in the table, a pointer
 * to a %NULL pointer will be returned.  To insert a item, this %NULL
 * pointer should be updated to point to the new #GHashNode.
 *
 * If @hash_return is a pass-by-reference parameter.  If it is
 * non-%NULL then the computed hash value is returned.  This is to
 * save insertions from having to compute the hash record again for
 * the new record.
 */
static inline GHashNode **
g_hash_table_lookup_node (GHashTable    *hash_table,
                          gconstpointer  key,
                          guint         *hash_return)
{
  GHashNode **node_ptr, *node;
  guint hash_value;

  hash_value = (* hash_table->hash_func) (key);
  node_ptr = &hash_table->nodes[hash_value % hash_table->size];

  if (hash_return)
    *hash_return = hash_value;

  /* Hash table lookup needs to be fast.
   *  We therefore remove the extra conditional of testing
   *  whether to call the key_equal_func or not from
   *  the inner loop.
   *
   *  Additional optimisation: first check if our full hash
   *  values are equal so we can avoid calling the full-blown
   *  key equality function in most cases.
   */
  if (hash_table->key_equal_func)
    {
      while ((node = *node_ptr))
        {
          if (node->key_hash == hash_value &&
              hash_table->key_equal_func (node->key, key))
            break;

          node_ptr = &(*node_ptr)->next;
        }
    }
  else
    {
      while ((node = *node_ptr))
        {
          if (node->key == key)
            break;

          node_ptr = &(*node_ptr)->next;
        }
    }

  return node_ptr;
}

/*
 * g_hash_table_remove_node:
 * @hash_table: our #GHashTable
 * @node_ptr_ptr: a pointer to the return value from
 *   g_hash_table_lookup_node()
 * @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 freed.  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.
 *
 * @node_ptr_ptr is a pass-by-reference in/out parameter.  When the
 * function is called, it should point to the pointer to the node to
 * remove.  This level of indirection is required so that the pointer
 * may be updated appropriately once the node has been removed.
 *
 * Before the function returns, the pointer at @node_ptr_ptr will be
 * updated to point to the position in the table that contains the
 * pointer to the "next" node in the chain.  This makes this function
 * convenient to use from functions that iterate over the entire
 * table.  If there is no further item in the chain then the
 * #GHashNode pointer will be %NULL (ie: **node_ptr_ptr == %NULL).
 *
 * Since the pointer in the table to the removed node is replaced with
 * either a pointer to the next node or a %NULL pointer as
 * appropriate, the pointer at the end of @node_ptr_ptr will never be
 * modified at all.  Stay tuned. :)
 */
static void
g_hash_table_remove_node (GHashTable   *hash_table,
                          GHashNode  ***node_ptr_ptr,
                          gboolean      notify)
{
  GHashNode **node_ptr, *node;

  node_ptr = *node_ptr_ptr;
  node = *node_ptr;

  *node_ptr = node->next;

  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);

  g_slice_free (GHashNode, node);

  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)
{
  GHashNode **node_ptr;
  int i;

  for (i = 0; i < hash_table->size; i++)
    for (node_ptr = &hash_table->nodes[i]; *node_ptr != NULL;)
      g_hash_table_remove_node (hash_table, &node_ptr, notify);

  hash_table->nnodes = 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.
 */
static void
g_hash_table_resize (GHashTable *hash_table)
{
  GHashNode **new_nodes;
  GHashNode *node;
  GHashNode *next;
  guint hash_val;
  gint new_size;
  gint i;

  new_size = g_spaced_primes_closest (hash_table->nnodes);
  new_size = CLAMP (new_size, HASH_TABLE_MIN_SIZE, HASH_TABLE_MAX_SIZE);

  new_nodes = g_new0 (GHashNode*, new_size);

  for (i = 0; i < hash_table->size; i++)
    for (node = hash_table->nodes[i]; node; node = next)
      {
	next = node->next;

	hash_val = node->key_hash % new_size;

	node->next = new_nodes[hash_val];
	new_nodes[hash_val] = node;
      }

  g_free (hash_table->nodes);
  hash_table->nodes = new_nodes;
  hash_table->size = new_size;
}

/*
 * 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 nnodes = hash_table->nnodes;
  gint size = hash_table->size;

  if ((size >= 3 * nnodes && size > HASH_TABLE_MIN_SIZE) ||
      (3 * size <= nnodes && size < HASH_TABLE_MAX_SIZE))
    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() 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() 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);
  hash_table->size               = HASH_TABLE_MIN_SIZE;
  hash_table->nnodes             = 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)) 
 *   {
 *     /&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->prev_node = NULL;
  ri->node = NULL;
  ri->position = -1;
  ri->pre_advanced = FALSE;
#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;

  g_return_val_if_fail (iter != NULL, FALSE);
  g_return_val_if_fail (ri->version == ri->hash_table->version, FALSE);

  if (ri->pre_advanced)
    {
      ri->pre_advanced = FALSE;

      if (ri->node == NULL)
	return FALSE;
    }
  else
    {
      if (ri->node != NULL)
	{
	  ri->prev_node = ri->node;
	  ri->node = ri->node->next;
	}

      while (ri->node == NULL)
	{
	  ri->position++;
	  if (ri->position >= ri->hash_table->size)
	    return FALSE;

	  ri->prev_node = NULL;
	  ri->node = ri->hash_table->nodes[ri->position];
	}
    }

  if (key != NULL)
    *key = ri->node->key;
  if (value != NULL)
    *value = ri->node->value;

  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)
{
  GHashNode *prev;
  GHashNode *node;
  int position;

  g_return_if_fail (ri != NULL);
  g_return_if_fail (ri->version == ri->hash_table->version);
  g_return_if_fail (ri->node != NULL);

  prev = ri->prev_node;
  node = ri->node;
  position = ri->position;

  /* pre-advance the iterator since we will remove the node */

  ri->node = ri->node->next;
  /* ri->prev_node is still the correct previous node */

  while (ri->node == NULL)
    {
      ri->position++;
      if (ri->position >= ri->hash_table->size)
	break;

      ri->prev_node = NULL;
      ri->node = ri->hash_table->nodes[ri->position];
    }

  ri->pre_advanced = TRUE;

  /* remove the node */

  if (prev != NULL)
    prev->next = node->next;
  else
    ri->hash_table->nodes[position] = node->next;

  if (notify)
    {
      if (ri->hash_table->key_destroy_func)
	ri->hash_table->key_destroy_func(node->key);
      if (ri->hash_table->value_destroy_func)
	ri->hash_table->value_destroy_func(node->value);
    }

  g_slice_free (GHashNode, node);

  ri->hash_table->nnodes--;
}

/**
 * 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;

  g_return_val_if_fail (hash_table != NULL, NULL);

  node = *g_hash_table_lookup_node (hash_table, key, NULL);

  return node ? node->value : NULL;
}

/**
 * g_hash_table_lookup_extended:
 * @hash_table: a #GHashTable.
 * @lookup_key: the key to look up.
 * @orig_key: returns the original key.
 * @value: returns the value associated with the key.
 *
 * 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().
 *
 * 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;

  g_return_val_if_fail (hash_table != NULL, FALSE);

  node = *g_hash_table_lookup_node (hash_table, lookup_key, NULL);

  if (node == NULL)
    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_ptr, *node;
  guint key_hash;

  g_return_if_fail (hash_table != NULL);
  g_return_if_fail (hash_table->ref_count > 0);

  node_ptr = g_hash_table_lookup_node (hash_table, key, &key_hash);

  if ((node = *node_ptr))
    {
      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 = g_slice_new (GHashNode);

      node->key = key;
      node->value = value;
      node->key_hash = key_hash;
      node->next = NULL;

      *node_ptr = node;
      hash_table->nnodes++;
      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_ptr;

  g_return_val_if_fail (hash_table != NULL, FALSE);

  node_ptr = g_hash_table_lookup_node (hash_table, key, NULL);
  if (*node_ptr == NULL)
    return FALSE;

  g_hash_table_remove_node (hash_table, &node_ptr, 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)
{
  GHashNode *node, **node_ptr;
  guint deleted = 0;
  gint i;

  for (i = 0; i < hash_table->size; i++)
    for (node_ptr = &hash_table->nodes[i]; (node = *node_ptr) != NULL;)
      if ((* func) (node->key, node->value, user_data))
        {
          g_hash_table_remove_node (hash_table, &node_ptr, notify);
          deleted++;
        }
      else
        node_ptr = &node->next;

  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 #GHashTableIterator 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 #GHashTableIterator 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)
{
  GHashNode *node;
  gint i;

  g_return_if_fail (hash_table != NULL);
  g_return_if_fail (func != NULL);

  for (i = 0; i < hash_table->size; i++)
    for (node = hash_table->nodes[i]; node; node = node->next)
      (* 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)
{
  GHashNode *node;
  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++)
    for (node = hash_table->nodes[i]; node; node = node->next)
      if (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)
{
  GHashNode *node;
  gint i;
  GList *retval;

  g_return_val_if_fail (hash_table != NULL, NULL);

  retval = NULL;
  for (i = 0; i < hash_table->size; i++)
    for (node = hash_table->nodes[i]; node; node = node->next)
      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)
{
  GHashNode *node;
  gint i;
  GList *retval;

  g_return_val_if_fail (hash_table != NULL, NULL);

  retval = NULL;
  for (i = 0; i < hash_table->size; i++)
    for (node = hash_table->nodes[i]; node; node = node->next)
      retval = g_list_prepend (retval, node->value);

  return retval;
}

#define __G_HASH_C__
#include "galiasdef.c"