/* GLIB - Library of useful routines for C programming

 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald

 * Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

 *

 * 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;

};

struct _GHashTable

{

  gint             size;

  gint             nnodes;

  GHashNode      **nodes;

  GHashFunc        hash_func;

  GEqualFunc       key_equal_func;

  volatile guint   ref_count;

  GDestroyNotify   key_destroy_func;

  GDestroyNotify   value_destroy_func;

};

#define G_HASH_TABLE_RESIZE(hash_table)				\

   G_STMT_START {						\

     if ((hash_table->size >= 3 * hash_table->nnodes &&	        \

	  hash_table->size > HASH_TABLE_MIN_SIZE) ||		\

	 (3 * hash_table->size <= hash_table->nnodes &&	        \

	  hash_table->size < HASH_TABLE_MAX_SIZE))		\

	   g_hash_table_resize (hash_table);			\

   } G_STMT_END

static void		g_hash_table_resize	  (GHashTable	  *hash_table);

static GHashNode**	g_hash_table_lookup_node  (GHashTable     *hash_table,

                                                   gconstpointer   key);

static GHashNode*	g_hash_node_new		  (gpointer	   key,

                                                   gpointer        value);

static void		g_hash_node_destroy	  (GHashNode	  *hash_node,

                                                   GDestroyNotify  key_destroy_func,

                                                   GDestroyNotify  value_destroy_func);

static void		g_hash_nodes_destroy	  (GHashNode	  *hash_node,

						  GDestroyNotify   key_destroy_func,

						  GDestroyNotify   value_destroy_func);

static guint g_hash_table_foreach_remove_or_steal (GHashTable     *hash_table,

                                                   GHRFunc	   func,

                                                   gpointer	   user_data,

                                                   gboolean        notify);

/**

 * 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.

 **/

EXPORT_C 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.

 **/

EXPORT_C 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;

  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_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

 **/

EXPORT_C 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 (FIX_CASTING(volatile int *)&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

 **/

EXPORT_C 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 (FIX_CASTING(volatile int *)&hash_table->ref_count, -1) - 1 == 0)

    {

      gint i;

      for (i = 0; i < hash_table->size; i++)

        g_hash_nodes_destroy (hash_table->nodes[i], 

                              hash_table->key_destroy_func,

                              hash_table->value_destroy_func);

      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.

 **/

EXPORT_C void

g_hash_table_destroy (GHashTable *hash_table)

{

  gint i;

  g_return_if_fail (hash_table != NULL);

  g_return_if_fail (hash_table->ref_count > 0);

  for (i = 0; i < hash_table->size; i++)

    {

      g_hash_nodes_destroy (hash_table->nodes[i], 

                            hash_table->key_destroy_func,

                            hash_table->value_destroy_func);

      hash_table->nodes[i] = NULL;

    }

  hash_table->nnodes = 0;

  hash_table->size = HASH_TABLE_MIN_SIZE;

  g_hash_table_unref (hash_table);

}

static inline GHashNode**

g_hash_table_lookup_node (GHashTable	*hash_table,

			  gconstpointer	 key)

{

  GHashNode **node;

  node = &hash_table->nodes

    [(* hash_table->hash_func) (key) % hash_table->size];

  /* 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.

   */

  if (hash_table->key_equal_func)

    while (*node && !(*hash_table->key_equal_func) ((*node)->key, key))

      node = &(*node)->next;

  else

    while (*node && (*node)->key != key)

      node = &(*node)->next;

  return node;

}

/**

 * 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.

 **/

EXPORT_C 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);

  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.

 **/

EXPORT_C 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);

  if (node)

    {

      if (orig_key)

	*orig_key = node->key;

      if (value)

	*value = node->value;

      return TRUE;

    }

  else

    return FALSE;

}

/**

 * 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.

 **/

EXPORT_C void

g_hash_table_insert (GHashTable *hash_table,

		     gpointer	 key,

		     gpointer	 value)

{

  GHashNode **node;

  g_return_if_fail (hash_table != NULL);

  g_return_if_fail (hash_table->ref_count > 0);

  node = g_hash_table_lookup_node (hash_table, key);

  if (*node)

    {

      /* do not reset node->key in this place, keeping

       * the old key is the intended behaviour. 

       * g_hash_table_replace() can be used instead.

       */

      /* free the passed key */

      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_hash_node_new (key, value);

      hash_table->nnodes++;

      G_HASH_TABLE_RESIZE (hash_table);

    }

}

/**

 * 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. 

 **/

EXPORT_C void

g_hash_table_replace (GHashTable *hash_table,

		      gpointer	  key,

		      gpointer	  value)

{

  GHashNode **node;

  g_return_if_fail (hash_table != NULL);

  g_return_if_fail (hash_table->ref_count > 0);

  node = g_hash_table_lookup_node (hash_table, key);

  if (*node)

    {

      if (hash_table->key_destroy_func)

	hash_table->key_destroy_func ((*node)->key);

      if (hash_table->value_destroy_func)

	hash_table->value_destroy_func ((*node)->value);

      (*node)->key   = key;

      (*node)->value = value;

    }

  else

    {

      *node = g_hash_node_new (key, value);

      hash_table->nnodes++;

      G_HASH_TABLE_RESIZE (hash_table);

    }

}

/**

 * 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.

 **/

EXPORT_C gboolean

g_hash_table_remove (GHashTable	   *hash_table,

		     gconstpointer  key)

{

  GHashNode **node, *dest;

  g_return_val_if_fail (hash_table != NULL, FALSE);

  node = g_hash_table_lookup_node (hash_table, key);

  if (*node)

    {

      dest = *node;

      (*node) = dest->next;

      g_hash_node_destroy (dest, 

			   hash_table->key_destroy_func,

			   hash_table->value_destroy_func);

      hash_table->nnodes--;

      G_HASH_TABLE_RESIZE (hash_table);

      return TRUE;

    }

  return FALSE;

}

/**

 * 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.

 **/

EXPORT_C gboolean

g_hash_table_steal (GHashTable    *hash_table,

                    gconstpointer  key)

{

  GHashNode **node, *dest;

  g_return_val_if_fail (hash_table != NULL, FALSE);

  node = g_hash_table_lookup_node (hash_table, key);

  if (*node)

    {

      dest = *node;

      (*node) = dest->next;

      g_hash_node_destroy (dest, NULL, NULL);

      hash_table->nnodes--;

      G_HASH_TABLE_RESIZE (hash_table);

      return TRUE;

    }

  return FALSE;

}

/**

 * 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.

 * 

 * Return value: the number of key/value pairs removed.

 **/

EXPORT_C 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.

 * 

 * Return value: the number of key/value pairs removed.

 **/

EXPORT_C guint