1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
20 * file for a list of people on the GLib Team. See the ChangeLog
21 * files for a list of changes. These files are distributed with
22 * GLib at ftp://ftp.gtk.org/pub/gtk/.
33 #include "gtestutils.h"
37 * SECTION:linked_lists_single
38 * @title: Singly-Linked Lists
39 * @short_description: linked lists that can be iterated in one direction
41 * The #GSList structure and its associated functions provide a
42 * standard singly-linked list data structure. The benefit of this
43 * data-structure is to provide insertion/deletion operations in O(1)
44 * complexity where access/search operations are in O(n). The benefit
45 * of #GSList over #GList (doubly linked list) is that they are lighter
46 * in space as they only need to retain one pointer but it double the
47 * cost of the worst case access/search operations.
49 * Each element in the list contains a piece of data, together with a
50 * pointer which links to the next element in the list. Using this
51 * pointer it is possible to move through the list in one direction
52 * only (unlike the [double-linked lists][glib-Doubly-Linked-Lists],
53 * which allow movement in both directions).
55 * The data contained in each element can be either integer values, by
56 * using one of the [Type Conversion Macros][glib-Type-Conversion-Macros],
57 * or simply pointers to any type of data.
59 * List elements are allocated from the [slice allocator][glib-Memory-Slices],
60 * which is more efficient than allocating elements individually.
62 * Note that most of the #GSList functions expect to be passed a
63 * pointer to the first element in the list. The functions which insert
64 * elements return the new start of the list, which may have changed.
66 * There is no function to create a #GSList. %NULL is considered to be
67 * the empty list so you simply set a #GSList* to %NULL.
69 * To add elements, use g_slist_append(), g_slist_prepend(),
70 * g_slist_insert() and g_slist_insert_sorted().
72 * To remove elements, use g_slist_remove().
74 * To find elements in the list use g_slist_last(), g_slist_next(),
75 * g_slist_nth(), g_slist_nth_data(), g_slist_find() and
76 * g_slist_find_custom().
78 * To find the index of an element use g_slist_position() and
81 * To call a function for each element in the list use
84 * To free the entire list, use g_slist_free().
89 * @data: holds the element's data, which can be a pointer to any kind
90 * of data, or any integer value using the
91 * [Type Conversion Macros][glib-Type-Conversion-Macros]
92 * @next: contains the link to the next element in the list.
94 * The #GSList struct is used for each element in the singly-linked
100 * @slist: an element in a #GSList.
102 * A convenience macro to get the next element in a #GSList.
103 * Note that it is considered perfectly acceptable to access
104 * @slist->next directly.
106 * Returns: the next element, or %NULL if there are no more elements.
109 #define _g_slist_alloc0() g_slice_new0 (GSList)
110 #define _g_slist_alloc() g_slice_new (GSList)
111 #define _g_slist_free1(slist) g_slice_free (GSList, slist)
116 * Allocates space for one #GSList element. It is called by the
117 * g_slist_append(), g_slist_prepend(), g_slist_insert() and
118 * g_slist_insert_sorted() functions and so is rarely used on its own.
120 * Returns: a pointer to the newly-allocated #GSList element.
125 return _g_slist_alloc0 ();
130 * @list: the first link of a #GSList
132 * Frees all of the memory used by a #GSList.
133 * The freed elements are returned to the slice allocator.
135 * If list elements contain dynamically-allocated memory,
136 * you should either use g_slist_free_full() or free them manually
139 * It can be combined with g_steal_pointer() to ensure the list head pointer
140 * is not left dangling:
141 * |[<!-- language="C" -->
142 * GSList *list_of_borrowed_things = …; /<!-- -->* (transfer container) *<!-- -->/
143 * g_slist_free (g_steal_pointer (&list_of_borrowed_things));
147 g_slist_free (GSList *list)
149 g_slice_free_chain (GSList, list, next);
154 * @list: a #GSList element
156 * Frees one #GSList element.
157 * It is usually used after g_slist_remove_link().
162 * A macro which does the same as g_slist_free_1().
167 g_slist_free_1 (GSList *list)
169 _g_slist_free1 (list);
174 * @list: the first link of a #GSList
175 * @free_func: the function to be called to free each element's data
177 * Convenience method, which frees all the memory used by a #GSList, and
178 * calls the specified destroy function on every element's data.
180 * @free_func must not modify the list (eg, by removing the freed
183 * It can be combined with g_steal_pointer() to ensure the list head pointer
184 * is not left dangling — this also has the nice property that the head pointer
185 * is cleared before any of the list elements are freed, to prevent double frees
187 * |[<!-- language="C" -->
188 * GSList *list_of_owned_things = …; /<!-- -->* (transfer full) (element-type GObject) *<!-- -->/
189 * g_slist_free_full (g_steal_pointer (&list_of_owned_things), g_object_unref);
195 g_slist_free_full (GSList *list,
196 GDestroyNotify free_func)
198 g_slist_foreach (list, (GFunc) free_func, NULL);
205 * @data: the data for the new element
207 * Adds a new element on to the end of the list.
209 * The return value is the new start of the list, which may
210 * have changed, so make sure you store the new value.
212 * Note that g_slist_append() has to traverse the entire list
213 * to find the end, which is inefficient when adding multiple
214 * elements. A common idiom to avoid the inefficiency is to prepend
215 * the elements and reverse the list when all elements have been added.
217 * |[<!-- language="C" -->
218 * // Notice that these are initialized to the empty list.
219 * GSList *list = NULL, *number_list = NULL;
221 * // This is a list of strings.
222 * list = g_slist_append (list, "first");
223 * list = g_slist_append (list, "second");
225 * // This is a list of integers.
226 * number_list = g_slist_append (number_list, GINT_TO_POINTER (27));
227 * number_list = g_slist_append (number_list, GINT_TO_POINTER (14));
230 * Returns: the new start of the #GSList
233 g_slist_append (GSList *list,
239 new_list = _g_slist_alloc ();
240 new_list->data = data;
241 new_list->next = NULL;
245 last = g_slist_last (list);
246 /* g_assert (last != NULL); */
247 last->next = new_list;
258 * @data: the data for the new element
260 * Adds a new element on to the start of the list.
262 * The return value is the new start of the list, which
263 * may have changed, so make sure you store the new value.
265 * |[<!-- language="C" -->
266 * // Notice that it is initialized to the empty list.
267 * GSList *list = NULL;
268 * list = g_slist_prepend (list, "last");
269 * list = g_slist_prepend (list, "first");
272 * Returns: the new start of the #GSList
275 g_slist_prepend (GSList *list,
280 new_list = _g_slist_alloc ();
281 new_list->data = data;
282 new_list->next = list;
290 * @data: the data for the new element
291 * @position: the position to insert the element.
292 * If this is negative, or is larger than the number
293 * of elements in the list, the new element is added on
294 * to the end of the list.
296 * Inserts a new element into the list at the given position.
298 * Returns: the new start of the #GSList
301 g_slist_insert (GSList *list,
310 return g_slist_append (list, data);
311 else if (position == 0)
312 return g_slist_prepend (list, data);
314 new_list = _g_slist_alloc ();
315 new_list->data = data;
319 new_list->next = NULL;
326 while ((position-- > 0) && tmp_list)
328 prev_list = tmp_list;
329 tmp_list = tmp_list->next;
332 new_list->next = prev_list->next;
333 prev_list->next = new_list;
339 * g_slist_insert_before:
341 * @sibling: node to insert @data before
342 * @data: data to put in the newly-inserted node
344 * Inserts a node before @sibling containing @data.
346 * Returns: the new head of the list.
349 g_slist_insert_before (GSList *slist,
355 slist = _g_slist_alloc ();
358 g_return_val_if_fail (sibling == NULL, slist);
363 GSList *node, *last = NULL;
365 for (node = slist; node; last = node, node = last->next)
370 node = _g_slist_alloc ();
378 node = _g_slist_alloc ();
380 node->next = last->next;
391 * @list2: the #GSList to add to the end of the first #GSList
393 * Adds the second #GSList onto the end of the first #GSList.
394 * Note that the elements of the second #GSList are not copied.
395 * They are used directly.
397 * Returns: the start of the new #GSList
400 g_slist_concat (GSList *list1, GSList *list2)
405 g_slist_last (list1)->next = list2;
414 _g_slist_remove_data (GSList *list,
419 GSList **previous_ptr = &list;
421 while (*previous_ptr)
424 if (tmp->data == data)
426 *previous_ptr = tmp->next;
427 g_slist_free_1 (tmp);
433 previous_ptr = &tmp->next;
442 * @data: the data of the element to remove
444 * Removes an element from a #GSList.
445 * If two elements contain the same data, only the first is removed.
446 * If none of the elements contain the data, the #GSList is unchanged.
448 * Returns: the new start of the #GSList
451 g_slist_remove (GSList *list,
454 return _g_slist_remove_data (list, data, FALSE);
458 * g_slist_remove_all:
460 * @data: data to remove
462 * Removes all list nodes with data equal to @data.
463 * Returns the new head of the list. Contrast with
464 * g_slist_remove() which removes only the first node
465 * matching the given data.
467 * Returns: new head of @list
470 g_slist_remove_all (GSList *list,
473 return _g_slist_remove_data (list, data, TRUE);
476 static inline GSList*
477 _g_slist_remove_link (GSList *list,
481 GSList **previous_ptr = &list;
483 while (*previous_ptr)
488 *previous_ptr = tmp->next;
493 previous_ptr = &tmp->next;
500 * g_slist_remove_link:
502 * @link_: an element in the #GSList
504 * Removes an element from a #GSList, without
505 * freeing the element. The removed element's next
506 * link is set to %NULL, so that it becomes a
507 * self-contained list with one element.
509 * Removing arbitrary nodes from a singly-linked list
510 * requires time that is proportional to the length of the list
511 * (ie. O(n)). If you find yourself using g_slist_remove_link()
512 * frequently, you should consider a different data structure,
513 * such as the doubly-linked #GList.
515 * Returns: the new start of the #GSList, without the element
518 g_slist_remove_link (GSList *list,
521 return _g_slist_remove_link (list, link_);
525 * g_slist_delete_link:
527 * @link_: node to delete
529 * Removes the node link_ from the list and frees it.
530 * Compare this to g_slist_remove_link() which removes the node
531 * without freeing it.
533 * Removing arbitrary nodes from a singly-linked list requires time
534 * that is proportional to the length of the list (ie. O(n)). If you
535 * find yourself using g_slist_delete_link() frequently, you should
536 * consider a different data structure, such as the doubly-linked
539 * Returns: the new head of @list
542 g_slist_delete_link (GSList *list,
545 list = _g_slist_remove_link (list, link_);
546 _g_slist_free1 (link_);
557 * Note that this is a "shallow" copy. If the list elements
558 * consist of pointers to data, the pointers are copied but
559 * the actual data isn't. See g_slist_copy_deep() if you need
560 * to copy the data as well.
562 * Returns: a copy of @list
565 g_slist_copy (GSList *list)
567 return g_slist_copy_deep (list, NULL, NULL);
573 * @func: a copy function used to copy every element in the list
574 * @user_data: user data passed to the copy function @func, or #NULL
576 * Makes a full (deep) copy of a #GSList.
578 * In contrast with g_slist_copy(), this function uses @func to make a copy of
579 * each list element, in addition to copying the list container itself.
581 * @func, as a #GCopyFunc, takes two arguments, the data to be copied
582 * and a @user_data pointer. On common processor architectures, it's safe to
583 * pass %NULL as @user_data if the copy function takes only one argument. You
584 * may get compiler warnings from this though if compiling with GCC’s
585 * `-Wcast-function-type` warning.
587 * For instance, if @list holds a list of GObjects, you can do:
588 * |[<!-- language="C" -->
589 * another_list = g_slist_copy_deep (list, (GCopyFunc) g_object_ref, NULL);
592 * And, to entirely free the new list, you could do:
593 * |[<!-- language="C" -->
594 * g_slist_free_full (another_list, g_object_unref);
597 * Returns: a full copy of @list, use g_slist_free_full() to free it
602 g_slist_copy_deep (GSList *list, GCopyFunc func, gpointer user_data)
604 GSList *new_list = NULL;
610 new_list = _g_slist_alloc ();
612 new_list->data = func (list->data, user_data);
614 new_list->data = list->data;
619 last->next = _g_slist_alloc ();
622 last->data = func (list->data, user_data);
624 last->data = list->data;
637 * Reverses a #GSList.
639 * Returns: the start of the reversed #GSList
642 g_slist_reverse (GSList *list)
648 GSList *next = list->next;
662 * @n: the position of the element, counting from 0
664 * Gets the element at the given position in a #GSList.
666 * Returns: the element, or %NULL if the position is off
667 * the end of the #GSList
670 g_slist_nth (GSList *list,
673 while (n-- > 0 && list)
682 * @n: the position of the element
684 * Gets the data of the element at the given position.
686 * Returns: the element's data, or %NULL if the position
687 * is off the end of the #GSList
690 g_slist_nth_data (GSList *list,
693 while (n-- > 0 && list)
696 return list ? list->data : NULL;
702 * @data: the element data to find
704 * Finds the element in a #GSList which
705 * contains the given data.
707 * Returns: the found #GSList element,
708 * or %NULL if it is not found
711 g_slist_find (GSList *list,
716 if (list->data == data)
726 * g_slist_find_custom:
728 * @data: user data passed to the function
729 * @func: the function to call for each element.
730 * It should return 0 when the desired element is found
732 * Finds an element in a #GSList, using a supplied function to
733 * find the desired element. It iterates over the list, calling
734 * the given function which should return 0 when the desired
735 * element is found. The function takes two #gconstpointer arguments,
736 * the #GSList element's data as the first argument and the
739 * Returns: the found #GSList element, or %NULL if it is not found
742 g_slist_find_custom (GSList *list,
746 g_return_val_if_fail (func != NULL, list);
750 if (! func (list->data, data))
761 * @llink: an element in the #GSList
763 * Gets the position of the given element
764 * in the #GSList (starting from 0).
766 * Returns: the position of the element in the #GSList,
767 * or -1 if the element is not found
770 g_slist_position (GSList *list,
790 * @data: the data to find
792 * Gets the position of the element containing
793 * the given data (starting from 0).
795 * Returns: the index of the element containing the data,
796 * or -1 if the data is not found
799 g_slist_index (GSList *list,
807 if (list->data == data)
820 * Gets the last element in a #GSList.
822 * This function iterates over the whole list.
824 * Returns: the last element in the #GSList,
825 * or %NULL if the #GSList has no elements
828 g_slist_last (GSList *list)
843 * Gets the number of elements in a #GSList.
845 * This function iterates over the whole list to
846 * count its elements. To check whether the list is non-empty, it is faster to
847 * check @list against %NULL.
849 * Returns: the number of elements in the #GSList
852 g_slist_length (GSList *list)
869 * @func: the function to call with each element's data
870 * @user_data: user data to pass to the function
872 * Calls a function for each element of a #GSList.
874 * It is safe for @func to remove the element from @list, but it must
875 * not modify any part of the list after that element.
878 g_slist_foreach (GSList *list,
884 GSList *next = list->next;
885 (*func) (list->data, user_data);
891 g_slist_insert_sorted_real (GSList *list,
896 GSList *tmp_list = list;
897 GSList *prev_list = NULL;
901 g_return_val_if_fail (func != NULL, list);
905 new_list = _g_slist_alloc ();
906 new_list->data = data;
907 new_list->next = NULL;
911 cmp = ((GCompareDataFunc) func) (data, tmp_list->data, user_data);
913 while ((tmp_list->next) && (cmp > 0))
915 prev_list = tmp_list;
916 tmp_list = tmp_list->next;
918 cmp = ((GCompareDataFunc) func) (data, tmp_list->data, user_data);
921 new_list = _g_slist_alloc ();
922 new_list->data = data;
924 if ((!tmp_list->next) && (cmp > 0))
926 tmp_list->next = new_list;
927 new_list->next = NULL;
933 prev_list->next = new_list;
934 new_list->next = tmp_list;
939 new_list->next = list;
945 * g_slist_insert_sorted:
947 * @data: the data for the new element
948 * @func: the function to compare elements in the list.
949 * It should return a number > 0 if the first parameter
950 * comes after the second parameter in the sort order.
952 * Inserts a new element into the list, using the given
953 * comparison function to determine its position.
955 * Returns: the new start of the #GSList
958 g_slist_insert_sorted (GSList *list,
962 return g_slist_insert_sorted_real (list, data, (GFunc) func, NULL);
966 * g_slist_insert_sorted_with_data:
968 * @data: the data for the new element
969 * @func: the function to compare elements in the list.
970 * It should return a number > 0 if the first parameter
971 * comes after the second parameter in the sort order.
972 * @user_data: data to pass to comparison function
974 * Inserts a new element into the list, using the given
975 * comparison function to determine its position.
977 * Returns: the new start of the #GSList
982 g_slist_insert_sorted_with_data (GSList *list,
984 GCompareDataFunc func,
987 return g_slist_insert_sorted_real (list, data, (GFunc) func, user_data);
991 g_slist_sort_merge (GSList *l1,
1003 cmp = ((GCompareDataFunc) compare_func) (l1->data, l2->data, user_data);
1016 l->next= l1 ? l1 : l2;
1022 g_slist_sort_real (GSList *list,
1036 while ((l2 = l2->next) != NULL)
1038 if ((l2 = l2->next) == NULL)
1045 return g_slist_sort_merge (g_slist_sort_real (list, compare_func, user_data),
1046 g_slist_sort_real (l2, compare_func, user_data),
1054 * @compare_func: the comparison function used to sort the #GSList.
1055 * This function is passed the data from 2 elements of the #GSList
1056 * and should return 0 if they are equal, a negative value if the
1057 * first element comes before the second, or a positive value if
1058 * the first element comes after the second.
1060 * Sorts a #GSList using the given comparison function. The algorithm
1061 * used is a stable sort.
1063 * Returns: the start of the sorted #GSList
1066 g_slist_sort (GSList *list,
1067 GCompareFunc compare_func)
1069 return g_slist_sort_real (list, (GFunc) compare_func, NULL);
1073 * g_slist_sort_with_data:
1075 * @compare_func: comparison function
1076 * @user_data: data to pass to comparison function
1078 * Like g_slist_sort(), but the sort function accepts a user data argument.
1080 * Returns: new head of the list
1083 g_slist_sort_with_data (GSList *list,
1084 GCompareDataFunc compare_func,
1087 return g_slist_sort_real (list, (GFunc) compare_func, user_data);
1091 * g_clear_slist: (skip)
1092 * @slist_ptr: (not nullable): a #GSList return location
1093 * @destroy: (nullable): the function to pass to g_slist_free_full() or %NULL to not free elements
1095 * Clears a pointer to a #GSList, freeing it and, optionally, freeing its elements using @destroy.
1097 * @slist_ptr must be a valid pointer. If @slist_ptr points to a null #GSList, this does nothing.
1102 (g_clear_slist) (GSList **slist_ptr,
1103 GDestroyNotify destroy)
1113 g_slist_free_full (slist, destroy);
1115 g_slist_free (slist);