/* 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 "gslist.h"

#include "gtestutils.h"

#include "gslice.h"

/**

 * SECTION:linked_lists_single

 * @title: Singly-Linked Lists

 * @short_description: linked lists that can be iterated in one direction

 *

 * The #GSList structure and its associated functions provide a

 * standard singly-linked list data structure.

 *

 * Each element in the list contains a piece of data, together with a

 * pointer which links to the next element in the list. Using this

 * pointer it is possible to move through the list in one direction

 * only (unlike the 

 * linkend="glib-Doubly-Linked-Lists">Doubly-Linked Lists</link> which

 * allow movement in both directions).

 *

 * The data contained in each element can be either integer values, by

 * using one of the <link linkend="glib-Type-Conversion-Macros">Type

 * Conversion Macros</link>, or simply pointers to any type of data.

 *

 * List elements are allocated from the 

 * linkend="glib-Memory-Slices">slice allocator</link>, which is more

 * efficient than allocating elements individually.

 *

 * Note that most of the #GSList functions expect to be passed a

 * pointer to the first element in the list. The functions which insert

 * elements return the new start of the list, which may have changed.

 *

 * There is no function to create a #GSList. %NULL is considered to be

 * the empty list so you simply set a #GSList* to %NULL.

 *

 * To add elements, use g_slist_append(), g_slist_prepend(),

 * g_slist_insert() and g_slist_insert_sorted().

 *

 * To remove elements, use g_slist_remove().

 *

 * To find elements in the list use g_slist_last(), g_slist_next(),

 * g_slist_nth(), g_slist_nth_data(), g_slist_find() and

 * g_slist_find_custom().

 *

 * To find the index of an element use g_slist_position() and

 * g_slist_index().

 *

 * To call a function for each element in the list use

 * g_slist_foreach().

 *

 * To free the entire list, use g_slist_free().

 **/

/**

 * GSList:

 * @data: holds the element's data, which can be a pointer to any kind

 *        of data, or any integer value using the 

 *        linkend="glib-Type-Conversion-Macros">Type Conversion

 *        Macros</link>.

 * @next: contains the link to the next element in the list.

 *

 * The #GSList struct is used for each element in the singly-linked

 * list.

 **/

/**

 * g_slist_next:

 * @slist: an element in a #GSList.

 * @Returns: the next element, or %NULL if there are no more elements.

 *

 * A convenience macro to get the next element in a #GSList.

 **/

#define _g_slist_alloc0()       g_slice_new0 (GSList)

#define _g_slist_alloc()        g_slice_new (GSList)

#define _g_slist_free1(slist)   g_slice_free (GSList, slist)

/**

 * g_slist_alloc:

 * @Returns: a pointer to the newly-allocated #GSList element.

 *

 * Allocates space for one #GSList element. It is called by the

 * g_slist_append(), g_slist_prepend(), g_slist_insert() and

 * g_slist_insert_sorted() functions and so is rarely used on its own.

 **/

GSList*

g_slist_alloc (void)

{

  return _g_slist_alloc0 ();

}

/**

 * g_slist_free:

 * @list: a #GSList

 *

 * Frees all of the memory used by a #GSList.

 * The freed elements are returned to the slice allocator.

 *

 * <note><para>

 * If list elements contain dynamically-allocated memory,

 * you should either use g_slist_free_full() or free them manually

 * first.

 * </para></note>

 */

void

g_slist_free (GSList *list)

{

  g_slice_free_chain (GSList, list, next);

}

/**

 * g_slist_free_1:

 * @list: a #GSList element

 *

 * Frees one #GSList element.

 * It is usually used after g_slist_remove_link().

 */

/**

 * g_slist_free1:

 *

 * A macro which does the same as g_slist_free_1().

 *

 * Since: 2.10

 **/

void

g_slist_free_1 (GSList *list)

{

  _g_slist_free1 (list);

}

/**

 * g_slist_free_full:

 * @list: a pointer to a #GSList

 * @free_func: the function to be called to free each element's data

 *

 * Convenience method, which frees all the memory used by a #GSList, and

 * calls the specified destroy function on every element's data.

 *

 * Since: 2.28

 **/

void

g_slist_free_full (GSList         *list,

		   GDestroyNotify  free_func)

{

  g_slist_foreach (list, (GFunc) free_func, NULL);

  g_slist_free (list);

}

/**

 * g_slist_append:

 * @list: a #GSList

 * @data: the data for the new element

 *

 * Adds a new element on to the end of the list.

 *

 * <note><para>

 * The return value is the new start of the list, which may

 * have changed, so make sure you store the new value.

 * </para></note>

 *

 * <note><para>

 * Note that g_slist_append() has to traverse the entire list

 * to find the end, which is inefficient when adding multiple

 * elements. A common idiom to avoid the inefficiency is to prepend

 * the elements and reverse the list when all elements have been added.

 * </para></note>

 *

 * |[

 * /* Notice that these are initialized to the empty list. */

 * GSList *list = NULL, *number_list = NULL;

 *

 * /* This is a list of strings. */

 * list = g_slist_append (list, "first");

 * list = g_slist_append (list, "second");

 *

 * /* This is a list of integers. */

 * number_list = g_slist_append (number_list, GINT_TO_POINTER (27));

 * number_list = g_slist_append (number_list, GINT_TO_POINTER (14));

 * ]|

 *

 * Returns: the new start of the #GSList

 */

GSList*

g_slist_append (GSList   *list,

                gpointer  data)

{

  GSList *new_list;

  GSList *last;

  new_list = _g_slist_alloc ();

  new_list->data = data;

  new_list->next = NULL;

  if (list)

    {

      last = g_slist_last (list);

      /* g_assert (last != NULL); */

      last->next = new_list;

      return list;

    }

  else

    return new_list;

}

/**

 * g_slist_prepend:

 * @list: a #GSList

 * @data: the data for the new element

 *

 * Adds a new element on to the start of the list.

 *

 * <note><para>

 * The return value is the new start of the list, which

 * may have changed, so make sure you store the new value.

 * </para></note>

 *

 * |[

 * /* Notice that it is initialized to the empty list. */

 * GSList *list = NULL;

 * list = g_slist_prepend (list, "last");

 * list = g_slist_prepend (list, "first");

 * ]|

 *

 * Returns: the new start of the #GSList

 */

GSList*

g_slist_prepend (GSList   *list,

                 gpointer  data)

{

  GSList *new_list;

  new_list = _g_slist_alloc ();

  new_list->data = data;

  new_list->next = list;

  return new_list;

}

/**

 * g_slist_insert:

 * @list: a #GSList

 * @data: the data for the new element

 * @position: the position to insert the element.

 *     If this is negative, or is larger than the number

 *     of elements in the list, the new element is added on

 *     to the end of the list.

 *

 * Inserts a new element into the list at the given position.

 *

 * Returns: the new start of the #GSList

 */

GSList*

g_slist_insert (GSList   *list,

                gpointer  data,

                gint      position)

{

  GSList *prev_list;

  GSList *tmp_list;

  GSList *new_list;

  if (position < 0)

    return g_slist_append (list, data);

  else if (position == 0)

    return g_slist_prepend (list, data);

  new_list = _g_slist_alloc ();

  new_list->data = data;

  if (!list)

    {

      new_list->next = NULL;

      return new_list;

    }

  prev_list = NULL;

  tmp_list = list;

  while ((position-- > 0) && tmp_list)

    {

      prev_list = tmp_list;

      tmp_list = tmp_list->next;

    }

  new_list->next = prev_list->next;

  prev_list->next = new_list;

  return list;

}

/**

 * g_slist_insert_before:

 * @slist: a #GSList

 * @sibling: node to insert @data before

 * @data: data to put in the newly-inserted node

 *

 * Inserts a node before @sibling containing @data.

 *

 * Returns: the new head of the list.

 */

GSList*

g_slist_insert_before (GSList  *slist,

                       GSList  *sibling,

                       gpointer data)

{

  if (!slist)

    {

      slist = _g_slist_alloc ();

      slist->data = data;

      slist->next = NULL;

      g_return_val_if_fail (sibling == NULL, slist);

      return slist;

    }

  else

    {

      GSList *node, *last = NULL;

      for (node = slist; node; last = node, node = last->next)

        if (node == sibling)

          break;

      if (!last)

        {

          node = _g_slist_alloc ();

          node->data = data;

          node->next = slist;

          return node;

        }

      else

        {

          node = _g_slist_alloc ();

          node->data = data;

          node->next = last->next;

          last->next = node;

          return slist;

        }

    }

}

/**

 * g_slist_concat:

 * @list1: a #GSList

 * @list2: the #GSList to add to the end of the first #GSList

 *

 * Adds the second #GSList onto the end of the first #GSList.

 * Note that the elements of the second #GSList are not copied.

 * They are used directly.

 *

 * Returns: the start of the new #GSList

 */

GSList *

g_slist_concat (GSList *list1, GSList *list2)

{

  if (list2)

    {

      if (list1)

        g_slist_last (list1)->next = list2;

      else

        list1 = list2;

    }

  return list1;

}

/**

 * g_slist_remove:

 * @list: a #GSList

 * @data: the data of the element to remove

 *

 * Removes an element from a #GSList.

 * If two elements contain the same data, only the first is removed.

 * If none of the elements contain the data, the #GSList is unchanged.

 *

 * Returns: the new start of the #GSList

 */

GSList*

g_slist_remove (GSList        *list,

                gconstpointer  data)

{

  GSList *tmp, *prev = NULL;

  tmp = list;

  while (tmp)

    {

      if (tmp->data == data)

        {

          if (prev)

            prev->next = tmp->next;

          else

            list = tmp->next;

          g_slist_free_1 (tmp);

          break;

        }

      prev = tmp;

      tmp = prev->next;

    }

  return list;

}

/**

 * g_slist_remove_all:

 * @list: a #GSList

 * @data: data to remove

 *

 * Removes all list nodes with data equal to @data.

 * Returns the new head of the list. Contrast with

 * g_slist_remove() which removes only the first node

 * matching the given data.

 *

 * Returns: new head of @list

 */

GSList*

g_slist_remove_all (GSList        *list,

                    gconstpointer  data)

{

  GSList *tmp, *prev = NULL;

  tmp = list;

  while (tmp)

    {

      if (tmp->data == data)

        {

          GSList *next = tmp->next;

          if (prev)

            prev->next = next;

          else

            list = next;

          g_slist_free_1 (tmp);

          tmp = next;

        }

      else

        {

          prev = tmp;

          tmp = prev->next;

        }

    }

  return list;

}

static inline GSList*

_g_slist_remove_link (GSList *list,

                      GSList *link)

{

  GSList *tmp;

  GSList *prev;

  prev = NULL;

  tmp = list;

  while (tmp)

    {

      if (tmp == link)

        {

          if (prev)

            prev->next = tmp->next;

          if (list == tmp)

            list = list->next;

          tmp->next = NULL;

          break;

        }

      prev = tmp;

      tmp = tmp->next;

    }

  return list;

}

/**

 * g_slist_remove_link:

 * @list: a #GSList

 * @link_: an element in the #GSList

 *

 * Removes an element from a #GSList, without

 * freeing the element. The removed element's next

 * link is set to %NULL, so that it becomes a

 * self-contained list with one element.

 *

 * Returns: the new start of the #GSList, without the element

 */

GSList*

g_slist_remove_link (GSList *list,

                     GSList *link_)

{

  return _g_slist_remove_link (list, link_);

}

/**

 * g_slist_delete_link:

 * @list: a #GSList

 * @link_: node to delete

 *

 * Removes the node link_ from the list and frees it.

 * Compare this to g_slist_remove_link() which removes the node

 * without freeing it.

 *

 * Returns: the new head of @list

 */

GSList*

g_slist_delete_link (GSList *list,

                     GSList *link_)

{

  list = _g_slist_remove_link (list, link_);

  _g_slist_free1 (link_);

  return list;

}

/**

 * g_slist_copy:

 * @list: a #GSList

 *

 * Copies a #GSList.

 *

 * <note><para>

 * Note that this is a "shallow" copy. If the list elements

 * consist of pointers to data, the pointers are copied but

 * the actual data isn't.

 * </para></note>

 *

 * Returns: a copy of @list

 */

GSList*

g_slist_copy (GSList *list)

{

  GSList *new_list = NULL;

  if (list)

    {

      GSList *last;

      new_list = _g_slist_alloc ();

      new_list->data = list->data;

      last = new_list;

      list = list->next;

      while (list)

        {

          last->next = _g_slist_alloc ();

          last = last->next;

          last->data = list->data;

          list = list->next;

        }

      last->next = NULL;

    }

  return new_list;

}

/**

 * g_slist_reverse:

 * @list: a #GSList

 *

 * Reverses a #GSList.

 *

 * Returns: the start of the reversed #GSList

 */

GSList*

g_slist_reverse (GSList *list)

{

  GSList *prev = NULL;

  while (list)

    {

      GSList *next = list->next;

      list->next = prev;

      prev = list;

      list = next;

    }

  return prev;

}

/**

 * g_slist_nth:

 * @list: a #GSList

 * @n: the position of the element, counting from 0

 *

 * Gets the element at the given position in a #GSList.

 *

 * Returns: the element, or %NULL if the position is off

 *     the end of the #GSList

 */

GSList*

g_slist_nth (GSList *list,

             guint   n)

{

  while (n-- > 0 && list)

    list = list->next;

  return list;

}

/**

 * g_slist_nth_data:

 * @list: a #GSList

 * @n: the position of the element

 *

 * Gets the data of the element at the given position.

 *

 * Returns: the element's data, or %NULL if the position

 *     is off the end of the #GSList

 */

gpointer

g_slist_nth_data (GSList   *list,

                  guint     n)

{

  while (n-- > 0 && list)

    list = list->next;

  return list ? list->data : NULL;

}

/**

 * g_slist_find:

 * @list: a #GSList

 * @data: the element data to find

 *

 * Finds the element in a #GSList which

 * contains the given data.

 *

 * Returns: the found #GSList element,

 *     or %NULL if it is not found

 */

GSList*

g_slist_find (GSList        *list,

              gconstpointer  data)

{

  while (list)

    {

      if (list->data == data)

        break;

      list = list->next;

    }

  return list;

}

/**

 * g_slist_find_custom:

 * @list: a #GSList

 * @data: user data passed to the function

 * @func: the function to call for each element.

 *     It should return 0 when the desired element is found

 *

 * Finds an element in a #GSList, using a supplied function to

 * find the desired element. It iterates over the list, calling

 * the given function which should return 0 when the desired

 * element is found. The function takes two #gconstpointer arguments,

 * the #GSList element's data as the first argument and the

 * given user data.

 *

 * Returns: the found #GSList element, or %NULL if it is not found

 */

GSList*

g_slist_find_custom (GSList        *list,

                     gconstpointer  data,

                     GCompareFunc   func)

{

  g_return_val_if_fail (func != NULL, list);

  while (list)

    {

      if (! func (list->data, data))

        return list;

      list = list->next;

    }

  return NULL;

}

/**

 * g_slist_position:

 * @list: a #GSList

 * @llink: an element in the #GSList

 *

 * Gets the position of the given element

 * in the #GSList (starting from 0).

 *

 * Returns: the position of the element in the #GSList,

 *     or -1 if the element is not found

 */

gint

g_slist_position (GSList *list,

                  GSList *llink)

{

  gint i;

  i = 0;

  while (list)

    {

      if (list == llink)

        return i;

      i++;

      list = list->next;

    }

  return -1;

}

/**

 * g_slist_index:

 * @list: a #GSList

 * @data: the data to find

 *

 * Gets the position of the element containing

 * the given data (starting from 0).

 *

 * Returns: the index of the element containing the data,

 *     or -1 if the data is not found

 */

gint

g_slist_index (GSList        *list,

               gconstpointer  data)

{

  gint i;

  i = 0;

  while (list)

    {

      if (list->data == data)

        return i;

      i++;

      list = list->next;

    }

  return -1;

}

/**

 * g_slist_last:

 * @list: a #GSList

 *

 * Gets the last element in a #GSList.

 *

 * <note><para>

 * This function iterates over the whole list.

 * </para></note>

 *

 * Returns: the last element in the #GSList,

 *     or %NULL if the #GSList has no elements

 */

GSList*

g_slist_last (GSList *list)

{

  if (list)

    {

      while (list->next)

        list = list->next;

    }

  return list;

}

/**

 * g_slist_length:

 * @list: a #GSList

 *

 * Gets the number of elements in a #GSList.

 *

 * <note><para>

 * This function iterates over the whole list to

 * count its elements.

 * </para></note>

 *

 * Returns: the number of elements in the #GSList

 */

guint

g_slist_length (GSList *list)

{

  guint length;

  length = 0;

  while (list)

    {

      length++;

      list = list->next;

    }

  return length;

}

/**

 * g_slist_foreach:

 * @list: a #GSList

 * @func: the function to call with each element's data

 * @user_data: user data to pass to the function

 *

 * Calls a function for each element of a #GSList.

 */

void

g_slist_foreach (GSList   *list,

                 GFunc     func,

                 gpointer  user_data)

{

  while (list)

    {

      GSList *next = list->next;

      (*func) (list->data, user_data);

      list = next;

    }

}

static GSList*

g_slist_insert_sorted_real (GSList   *list,

                            gpointer  data,

                            GFunc     func,

                            gpointer  user_data)

{

  GSList *tmp_list = list;

  GSList *prev_list = NULL;

  GSList *new_list;

  gint cmp;

  g_return_val_if_fail (func != NULL, list);

  if (!list)

    {

      new_list = _g_slist_alloc ();

      new_list->data = data;

      new_list->next = NULL;

      return new_list;

    }

  cmp = ((GCompareDataFunc) func) (data, tmp_list->data, user_data);

  while ((tmp_list->next) && (cmp > 0))

    {

      prev_list = tmp_list;

      tmp_list = tmp_list->next;

      cmp = ((GCompareDataFunc) func) (data, tmp_list->data, user_data);

    }

  new_list = _g_slist_alloc ();

  new_list->data = data;

  if ((!tmp_list->next) && (cmp > 0))

    {