/* GLIB - Library of useful routines for C programming

 * Copyright (C) 1995-1998  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 2.1 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, see <http://www.gnu.org/licenses/>.

 */

/*

 * 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/. 

 */

#include "config.h"

#include "gtrashstack.h"

/**

 * SECTION:trash_stack

 * @title: Trash Stacks

 * @short_description: maintain a stack of unused allocated memory chunks

 *

 * A #GTrashStack is an efficient way to keep a stack of unused allocated

 * memory chunks. Each memory chunk is required to be large enough to hold

 * a #gpointer. This allows the stack to be maintained without any space

 * overhead, since the stack pointers can be stored inside the memory chunks.

 *

 * There is no function to create a #GTrashStack. A %NULL #GTrashStack*

 * is a perfectly valid empty stack.

 *

 * There is no longer any good reason to use #GTrashStack.  If you have

 * extra pieces of memory, free() them and allocate them again later.

 *

 * Deprecated: 2.48: #GTrashStack is deprecated without replacement

 */

/**

 * GTrashStack:

 * @next: pointer to the previous element of the stack,

 *     gets stored in the first `sizeof (gpointer)`

 *     bytes of the element

 *

 * Each piece of memory that is pushed onto the stack

 * is cast to a GTrashStack*.

 *

 * Deprecated: 2.48: #GTrashStack is deprecated without replacement

 */

/**

 * g_trash_stack_push:

 * @stack_p: a #GTrashStack

 * @data_p: (not nullable): the piece of memory to push on the stack

 *

 * Pushes a piece of memory onto a #GTrashStack.

 * Deprecated: 2.48: #GTrashStack is deprecated without replacement

 */

void

g_trash_stack_push (GTrashStack **stack_p,

                    gpointer      data_p)

{

  GTrashStack *data = (GTrashStack *) data_p;

  data->next = *stack_p;

  *stack_p = data;

}

/**

 * g_trash_stack_pop:

 * @stack_p: a #GTrashStack

 *

 * Pops a piece of memory off a #GTrashStack.

 *

 * Returns: the element at the top of the stack

 * Deprecated: 2.48: #GTrashStack is deprecated without replacement

 */

gpointer

g_trash_stack_pop (GTrashStack **stack_p)

{

  GTrashStack *data;

  data = *stack_p;

  if (data)

    {

      *stack_p = data->next;

      /* NULLify private pointer here, most platforms store NULL as

       * subsequent 0 bytes

       */

      data->next = NULL;

    }

  return data;

}

/**

 * g_trash_stack_peek:

 * @stack_p: a #GTrashStack

 *

 * Returns the element at the top of a #GTrashStack

 * which may be %NULL.

 *

 * Returns: the element at the top of the stack

 * Deprecated: 2.48: #GTrashStack is deprecated without replacement

 */

gpointer

g_trash_stack_peek (GTrashStack **stack_p)

{

  GTrashStack *data;

  data = *stack_p;

  return data;

}

/**

 * g_trash_stack_height:

 * @stack_p: a #GTrashStack

 *

 * Returns the height of a #GTrashStack.

 *

 * Note that execution of this function is of O(N) complexity

 * where N denotes the number of items on the stack.

 *

 * Returns: the height of the stack

 * Deprecated: 2.48: #GTrashStack is deprecated without replacement

 */

guint

g_trash_stack_height (GTrashStack **stack_p)

{

  GTrashStack *data;

  guint i = 0;

  for (data = *stack_p; data; data = data->next)

    i++;

  return i;

}