/* 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 "glist.h"
#include "gslice.h"
#include "gtestutils.h"
/**
* SECTION:linked_lists_double
* @title: Doubly-Linked Lists
* @short_description: linked lists that can be iterated over in both directions
*
* The #GList structure and its associated functions provide a standard
* doubly-linked list data structure.
*
* Each element in the list contains a piece of data, together with
* pointers which link to the previous and next elements in the list.
* Using these pointers it is possible to move through the list in both
* directions (unlike the <link
* linkend="glib-Singly-Linked-Lists">Singly-Linked Lists</link> which
* only allows movement through the list in the forward direction).
*
* 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 <link
* linkend="glib-Memory-Slices">slice allocator</link>, which is more
* efficient than allocating elements individually.
*
* Note that most of the #GList 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 #GList. %NULL is considered to be
* the empty list so you simply set a #GList* to %NULL.
*
* To add elements, use g_list_append(), g_list_prepend(),
* g_list_insert() and g_list_insert_sorted().
*
* To remove elements, use g_list_remove().
*
* To find elements in the list use g_list_first(), g_list_last(),
* g_list_next(), g_list_previous(), g_list_nth(), g_list_nth_data(),
* g_list_find() and g_list_find_custom().
*
* To find the index of an element use g_list_position() and
* g_list_index().
*
* To call a function for each element in the list use g_list_foreach().
*
* To free the entire list, use g_list_free().
**/
/**
* GList:
* @data: holds the element's data, which can be a pointer to any kind
* of data, or any integer value using the <link
* linkend="glib-Type-Conversion-Macros">Type Conversion
* Macros</link>.
* @next: contains the link to the next element in the list.
* @prev: contains the link to the previous element in the list.
*
* The #GList struct is used for each element in a doubly-linked list.
**/
/**
* g_list_previous:
* @list: an element in a #GList.
* @Returns: the previous element, or %NULL if there are no previous
* elements.
*
* A convenience macro to get the previous element in a #GList.
**/
/**
* g_list_next:
* @list: an element in a #GList.
* @Returns: the next element, or %NULL if there are no more elements.
*
* A convenience macro to get the next element in a #GList.
**/
#define _g_list_alloc() g_slice_new (GList)
#define _g_list_alloc0() g_slice_new0 (GList)
#define _g_list_free1(list) g_slice_free (GList, list)
/**
* g_list_alloc:
* @Returns: a pointer to the newly-allocated #GList element.
*
* Allocates space for one #GList element. It is called by
* g_list_append(), g_list_prepend(), g_list_insert() and
* g_list_insert_sorted() and so is rarely used on its own.
**/
GList*
g_list_alloc (void)
{
return _g_list_alloc0 ();
}
/**
* g_list_free:
* @list: a #GList
*
* Frees all of the memory used by a #GList.
* The freed elements are returned to the slice allocator.
*
* <note><para>
* If list elements contain dynamically-allocated memory,
* you should either use g_list_free_full() or free them manually
* first.
* </para></note>
*/
void
g_list_free (GList *list)
{
g_slice_free_chain (GList, list, next);
}
/**
* g_list_free_1:
* @list: a #GList element
*
* Frees one #GList element.
* It is usually used after g_list_remove_link().
*/
/**
* g_list_free1:
*
* Another name for g_list_free_1().
**/
void
g_list_free_1 (GList *list)
{
_g_list_free1 (list);
}
/**
* g_list_free_full:
* @list: a pointer to a #GList
* @free_func: the function to be called to free each element's data
*
* Convenience method, which frees all the memory used by a #GList, and
* calls the specified destroy function on every element's data.
*
* Since: 2.28
*/
void
g_list_free_full (GList *list,
GDestroyNotify free_func)
{
g_list_foreach (list, (GFunc) free_func, NULL);
g_list_free (list);
}
/**
* g_list_append:
* @list: a pointer to a #GList
* @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_list_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. */
* GList *list = NULL, *number_list = NULL;
*
* /* This is a list of strings. */
* list = g_list_append (list, "first");
* list = g_list_append (list, "second");
*
* /* This is a list of integers. */
* number_list = g_list_append (number_list, GINT_TO_POINTER (27));
* number_list = g_list_append (number_list, GINT_TO_POINTER (14));
* ]|
*
* Returns: the new start of the #GList
*/
GList*
g_list_append (GList *list,
gpointer data)
{
GList *new_list;
GList *last;
new_list = _g_list_alloc ();
new_list->data = data;
new_list->next = NULL;
if (list)
{
last = g_list_last (list);
/* g_assert (last != NULL); */
last->next = new_list;
new_list->prev = last;
return list;
}
else
{
new_list->prev = NULL;
return new_list;
}
}
/**
* g_list_prepend:
* @list: a pointer to a #GList
* @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. */
* GList *list = NULL;
* list = g_list_prepend (list, "last");
* list = g_list_prepend (list, "first");
* ]|
*
* Returns: the new start of the #GList
*/
GList*
g_list_prepend (GList *list,
gpointer data)
{
GList *new_list;
new_list = _g_list_alloc ();
new_list->data = data;
new_list->next = list;
if (list)
{
new_list->prev = list->prev;
if (list->prev)
list->prev->next = new_list;
list->prev = new_list;
}
else
new_list->prev = NULL;
return new_list;
}
/**
* g_list_insert:
* @list: a pointer to a #GList
* @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 #GList
*/
GList*
g_list_insert (GList *list,
gpointer data,
gint position)
{
GList *new_list;
GList *tmp_list;
if (position < 0)
return g_list_append (list, data);
else if (position == 0)
return g_list_prepend (list, data);
tmp_list = g_list_nth (list, position);
if (!tmp_list)
return g_list_append (list, data);
new_list = _g_list_alloc ();
new_list->data = data;
new_list->prev = tmp_list->prev;
tmp_list->prev->next = new_list;
new_list->next = tmp_list;
tmp_list->prev = new_list;
return list;
}
/**
* g_list_insert_before:
* @list: a pointer to a #GList
* @sibling: the list element before which the new element
* is inserted or %NULL to insert at the end of the list
* @data: the data for the new element
*
* Inserts a new element into the list before the given position.
*
* Returns: the new start of the #GList
*/
GList*
g_list_insert_before (GList *list,
GList *sibling,
gpointer data)
{
if (!list)
{
list = g_list_alloc ();
list->data = data;
g_return_val_if_fail (sibling == NULL, list);
return list;
}
else if (sibling)
{
GList *node;
node = _g_list_alloc ();
node->data = data;
node->prev = sibling->prev;
node->next = sibling;
sibling->prev = node;
if (node->prev)
{
node->prev->next = node;
return list;
}
else
{
g_return_val_if_fail (sibling == list, node);
return node;
}
}
else
{
GList *last;
last = list;
while (last->next)
last = last->next;
last->next = _g_list_alloc ();
last->next->data = data;
last->next->prev = last;
last->next->next = NULL;
return list;
}
}
/**
* g_list_concat:
* @list1: a #GList
* @list2: the #GList to add to the end of the first #GList
*
* Adds the second #GList onto the end of the first #GList.
* Note that the elements of the second #GList are not copied.
* They are used directly.
*
* Returns: the start of the new #GList
*/
GList *
g_list_concat (GList *list1, GList *list2)
{
GList *tmp_list;
if (list2)
{
tmp_list = g_list_last (list1);
if (tmp_list)
tmp_list->next = list2;
else
list1 = list2;
list2->prev = tmp_list;
}
return list1;
}
/**
* g_list_remove:
* @list: a #GList
* @data: the data of the element to remove
*
* Removes an element from a #GList.
* If two elements contain the same data, only the first is removed.
* If none of the elements contain the data, the #GList is unchanged.
*
* Returns: the new start of the #GList
*/
GList*
g_list_remove (GList *list,
gconstpointer data)
{
GList *tmp;
tmp = list;
while (tmp)
{
if (tmp->data != data)
tmp = tmp->next;
else
{
if (tmp->prev)
tmp->prev->next = tmp->next;
if (tmp->next)
tmp->next->prev = tmp->prev;
if (list == tmp)
list = list->next;
_g_list_free1 (tmp);
break;
}
}
return list;
}
/**
* g_list_remove_all:
* @list: a #GList
* @data: data to remove
*
* Removes all list nodes with data equal to @data.
* Returns the new head of the list. Contrast with
* g_list_remove() which removes only the first node
* matching the given data.
*
* Returns: new head of @list
*/
GList*
g_list_remove_all (GList *list,
gconstpointer data)
{
GList *tmp = list;
while (tmp)
{
if (tmp->data != data)
tmp = tmp->next;
else
{
GList *next = tmp->next;
if (tmp->prev)
tmp->prev->next = next;
else
list = next;
if (next)
next->prev = tmp->prev;
_g_list_free1 (tmp);
tmp = next;
}
}
return list;
}
static inline GList*
_g_list_remove_link (GList *list,
GList *link)
{
if (link)
{
if (link->prev)
link->prev->next = link->next;
if (link->next)
link->next->prev = link->prev;
if (link == list)
list = list->next;
link->next = NULL;
link->prev = NULL;
}
return list;
}
/**
* g_list_remove_link:
* @list: a #GList
* @llink: an element in the #GList
*
* Removes an element from a #GList, without freeing the element.
* The removed element's prev and next links are set to %NULL, so
* that it becomes a self-contained list with one element.
*
* Returns: the new start of the #GList, without the element
*/
GList*
g_list_remove_link (GList *list,
GList *llink)
{
return _g_list_remove_link (list, llink);
}
/**
* g_list_delete_link:
* @list: a #GList
* @link_: node to delete from @list
*
* Removes the node link_ from the list and frees it.
* Compare this to g_list_remove_link() which removes the node
* without freeing it.
*
* Returns: the new head of @list
*/
GList*
g_list_delete_link (GList *list,
GList *link_)
{
list = _g_list_remove_link (list, link_);
_g_list_free1 (link_);
return list;
}
/**
* g_list_copy:
* @list: a #GList
*
* Copies a #GList.
*
* <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 is not.
* </para></note>
*
* Returns: a copy of @list
*/
GList*
g_list_copy (GList *list)
{
GList *new_list = NULL;
if (list)
{
GList *last;
new_list = _g_list_alloc ();
new_list->data = list->data;
new_list->prev = NULL;
last = new_list;
list = list->next;
while (list)
{
last->next = _g_list_alloc ();
last->next->prev = last;
last = last->next;
last->data = list->data;
list = list->next;
}
last->next = NULL;
}
return new_list;
}
/**
* g_list_reverse:
* @list: a #GList
*
* Reverses a #GList.
* It simply switches the next and prev pointers of each element.
*
* Returns: the start of the reversed #GList
*/
GList*
g_list_reverse (GList *list)
{
GList *last;
last = NULL;
while (list)
{
last = list;
list = last->next;
last->next = last->prev;
last->prev = list;
}
return last;
}
/**
* g_list_nth:
* @list: a #GList
* @n: the position of the element, counting from 0
*
* Gets the element at the given position in a #GList.
*
* Returns: the element, or %NULL if the position is off
* the end of the #GList
*/
GList*
g_list_nth (GList *list,
guint n)
{
while ((n-- > 0) && list)
list = list->next;
return list;
}
/**
* g_list_nth_prev:
* @list: a #GList
* @n: the position of the element, counting from 0
*
* Gets the element @n places before @list.
*
* Returns: the element, or %NULL if the position is
* off the end of the #GList
*/
GList*
g_list_nth_prev (GList *list,
guint n)
{
while ((n-- > 0) && list)
list = list->prev;
return list;
}
/**
* g_list_nth_data:
* @list: a #GList
* @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 #GList
*/
gpointer
g_list_nth_data (GList *list,
guint n)
{
while ((n-- > 0) && list)
list = list->next;
return list ? list->data : NULL;
}
/**
* g_list_find:
* @list: a #GList
* @data: the element data to find
*
* Finds the element in a #GList which
* contains the given data.
*
* Returns: the found #GList element,
* or %NULL if it is not found
*/
GList*
g_list_find (GList *list,
gconstpointer data)
{
while (list)
{
if (list->data == data)
break;
list = list->next;
}
return list;
}
/**
* g_list_find_custom:
* @list: a #GList
* @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 #GList, 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 #GList element's data as the first argument and the
* given user data.
*
* Returns: the found #GList element, or %NULL if it is not found
*/
GList*
g_list_find_custom (GList *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_list_position:
* @list: a #GList
* @llink: an element in the #GList
*
* Gets the position of the given element
* in the #GList (starting from 0).
*
* Returns: the position of the element in the #GList,
* or -1 if the element is not found
*/
gint
g_list_position (GList *list,
GList *llink)
{
gint i;
i = 0;
while (list)
{
if (list == llink)
return i;
i++;
list = list->next;
}
return -1;
}
/**
* g_list_index:
* @list: a #GList
* @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_list_index (GList *list,
gconstpointer data)
{
gint i;
i = 0;
while (list)
{
if (list->data == data)
return i;
i++;
list = list->next;
}
return -1;
}
/**
* g_list_last:
* @list: a #GList
*
* Gets the last element in a #GList.
*
* Returns: the last element in the #GList,
* or %NULL if the #GList has no elements
*/
GList*
g_list_last (GList *list)
{
if (list)
{
while (list->next)
list = list->next;
}
return list;
}
/**
* g_list_first:
* @list: a #GList
*
* Gets the first element in a #GList.
*
* Returns: the first element in the #GList,
* or %NULL if the #GList has no elements
*/
GList*
g_list_first (GList *list)
{
if (list)
{
while (list->prev)
list = list->prev;
}
return list;
}
/**
* g_list_length:
* @list: a #GList
*
* Gets the number of elements in a #GList.
*
* <note><para>
* This function iterates over the whole list to
* count its elements.
* </para></note>
*
* Returns: the number of elements in the #GList
*/
guint
g_list_length (GList *list)
{
guint length;
length = 0;
while (list)
{
length++;
list = list->next;
}
return length;
}
/**
* g_list_foreach:
* @list: a #GList
* @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 #GList.
*/
/**
* GFunc:
* @data: the element's data.
* @user_data: user data passed to g_list_foreach() or
* g_slist_foreach().
*
* Specifies the type of functions passed to g_list_foreach() and
* g_slist_foreach().
**/
void
g_list_foreach (GList *list,
GFunc func,
gpointer user_data)
{
while (list)
{
GList *next = list->next;
(*func) (list->data, user_data);
list = next;
}
}
static GList*
g_list_insert_sorted_real (GList *list,
gpointer data,
GFunc func,
gpointer user_data)
{
GList *tmp_list = list;
GList *new_list;
gint cmp;
g_return_val_if_fail (func != NULL, list);
if (!list)
{
new_list = _g_list_alloc0 ();
new_list->data = data;
return new_list;
}
cmp = ((GCompareDataFunc) func) (data, tmp_list->data, user_data);
while ((tmp_list->next) && (cmp > 0))
{
tmp_list = tmp_list->next;
cmp = ((GCompareDataFunc) func) (data, tmp_list->data, user_data);
}
new_list = _g_list_alloc0 ();
new_list->data = data;
if ((!tmp_list->next) && (cmp > 0))
{
tmp_list->next = new_list;
new_list->prev = tmp_list;
return list;
}
if (tmp_list->prev)
{
tmp_list->prev->next = new_list;
new_list->prev = tmp_list->prev;
}
new_list->next = tmp_list;
tmp_list->prev = new_list;
if (tmp_list == list)
return new_list;
else
return list;
}
/**
* g_list_insert_sorted:
* @list: a pointer to a #GList
* @data: the data for the new element
* @func: the function to compare elements in the list. It should
* return a number > 0 if the first parameter comes after the
* second parameter in the sort order.
*
* Inserts a new element into the list, using the given comparison
* function to determine its position.
*
* Returns: the new start of the #GList
*/
GList*
g_list_insert_sorted (GList *list,
gpointer data,
GCompareFunc func)
{
return g_list_insert_sorted_real (list, data, (GFunc) func, NULL);
}
/**
* g_list_insert_sorted_with_data:
* @list: a pointer to a #GList
* @data: the data for the new element
* @func: the function to compare elements in the list.
* It should return a number > 0 if the first parameter
* comes after the second parameter in the sort order.
* @user_data: user data to pass to comparison function.
*
* Inserts a new element into the list, using the given comparison
* function to determine its position.
*
* Returns: the new start of the #GList
*
* Since: 2.10
*/
GList*
g_list_insert_sorted_with_data (GList *list,
gpointer data,
GCompareDataFunc func,
gpointer user_data)
{
return g_list_insert_sorted_real (list, data, (GFunc) func, user_data);
}
static GList *
g_list_sort_merge (GList *l1,
GList *l2,
GFunc compare_func,
gpointer user_data)
{
GList list, *l, *lprev;
gint cmp;
l = &list;
lprev = NULL;
while (l1 && l2)
{
cmp = ((GCompareDataFunc) compare_func) (l1->data, l2->data, user_data);
if (cmp <= 0)
{
l->next = l1;
l1 = l1->next;
}
else
{
l->next = l2;
l2 = l2->next;
}
l = l->next;
l->prev = lprev;
lprev = l;
}
l->next = l1 ? l1 : l2;
l->next->prev = l;
return list.next;
}
static GList*
g_list_sort_real (GList *list,
GFunc compare_func,
gpointer user_data)
{
GList *l1, *l2;
if (!list)
return NULL;
if (!list->next)
return list;
l1 = list;
l2 = list->next;
while ((l2 = l2->next) != NULL)
{
if ((l2 = l2->next) == NULL)
break;
l1 = l1->next;
}
l2 = l1->next;
l1->next = NULL;
return g_list_sort_merge (g_list_sort_real (list, compare_func, user_data),
g_list_sort_real (l2, compare_func, user_data),
compare_func,
user_data);
}
/**
* g_list_sort:
* @list: a #GList
* @compare_func: the comparison function used to sort the #GList.
* This function is passed the data from 2 elements of the #GList
* and should return 0 if they are equal, a negative value if the
* first element comes before the second, or a positive value if
* the first element comes after the second.
*
* Sorts a #GList using the given comparison function. The algorithm
* used is a stable sort.
*
* Returns: the start of the sorted #GList
*/
/**
* GCompareFunc:
* @a: a value.
* @b: a value to compare with.
* @Returns: negative value if @a < @b; zero if @a = @b; positive
* value if @a > @b.
*
* Specifies the type of a comparison function used to compare two
* values. The function should return a negative integer if the first
* value comes before the second, 0 if they are equal, or a positive
* integer if the first value comes after the second.
**/
GList *
g_list_sort (GList *list,
GCompareFunc compare_func)
{
return g_list_sort_real (list, (GFunc) compare_func, NULL);
}
/**
* g_list_sort_with_data:
* @list: a #GList
* @compare_func: comparison function
* @user_data: user data to pass to comparison function
*
* Like g_list_sort(), but the comparison function accepts
* a user data argument.
*
* Returns: the new head of @list
*/
/**
* GCompareDataFunc:
* @a: a value.
* @b: a value to compare with.
* @user_data: user data to pass to comparison function.
* @Returns: negative value if @a < @b; zero if @a = @b; positive
* value if @a > @b.
*
* Specifies the type of a comparison function used to compare two
* values. The function should return a negative integer if the first
* value comes before the second, 0 if they are equal, or a positive
* integer if the first value comes after the second.
**/
GList *
g_list_sort_with_data (GList *list,
GCompareDataFunc compare_func,
gpointer user_data)
{
return g_list_sort_real (list, (GFunc) compare_func, user_data);
}