/* 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 Singly-Linked Lists 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 Type * Conversion Macros, or simply pointers to any type of data. * * List elements are allocated from the slice allocator, 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 Type Conversion * Macros. * @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. * * A convenience macro to get the previous element in a #GList. * * Returns: the previous element, or %NULL if there are no previous * elements. **/ /** * g_list_next: * @list: an element in a #GList. * * A convenience macro to get the next element in a #GList. * * Returns: the next element, or %NULL if there are no more elements. **/ #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: * * 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. * * Returns: a pointer to the newly-allocated #GList element. **/ 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. * * * If list elements contain dynamically-allocated memory, * you should either use g_list_free_full() or free them manually * first. * */ 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. * * * The return value is the new start of the list, which * may have changed, so make sure you store the new value. * * * * 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. * * * |[ * /* 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. * * * The return value is the new start of the list, which * may have changed, so make sure you store the new value. * * * |[ * /* 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 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. See g_list_copy_deep() if you need * to copy the data as well. * * * Returns: a copy of @list */ GList* g_list_copy (GList *list) { return g_list_copy_deep (list, NULL, NULL); } /** * g_list_copy_deep: * @list: a #GList * @func: a copy function used to copy every element in the list * @user_data: user data passed to the copy function @func, or #NULL * * Makes a full (deep) copy of a #GList. * * In contrast with g_list_copy(), this function uses @func to make a copy of * each list element, in addition to copying the list container itself. * * @func, as a #GCopyFunc, takes two arguments, the data to be copied and a user * pointer. It's safe to pass #NULL as user_data, if the copy function takes only * one argument. * * For instance, if @list holds a list of GObjects, you can do: * |[ * another_list = g_list_copy_deep (list, (GCopyFunc) g_object_ref, NULL); * ]| * * And, to entirely free the new list, you could do: * |[ * g_list_free_full (another_list, g_object_unref); * ]| * * Returns: a full copy of @list, use #g_list_free_full to free it * * Since: 2.34 */ GList* g_list_copy_deep (GList *list, GCopyFunc func, gpointer user_data) { GList *new_list = NULL; if (list) { GList *last; new_list = _g_list_alloc (); if (func) new_list->data = func (list->data, user_data); else 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; if (func) last->data = func (list->data, user_data); else 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. * * * This function iterates over the whole list to * count its elements. * * * 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. * * 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. * * Returns: negative value if @a < @b; zero if @a = @b; positive * value if @a > @b. **/ 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. * * 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. * * Returns: negative value if @a < @b; zero if @a = @b; positive * value if @a > @b. **/ 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); }