/* 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, see . */ /* * 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 #include #include "flist.h" /** * SECTION:linked_lists_double * @title: Doubly-Linked Lists * @short_description: linked lists that can be iterated over in both directions * * The #FList 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 [GSList][glib-Singly-Linked-Lists], * which only allows movement through the list in the forward direction). * * The double linked list does not keep track of the number of items * and does not keep track of both the start and end of the list. If * you want fast access to both the start and the end of the list, * and/or the number of items in the list, use a * [GQueue][glib-Double-ended-Queues] instead. * * The data contained in each element can be either integer values, by * using one of the [Type Conversion Macros][glib-Type-Conversion-Macros], * or simply pointers to any type of data. * * List elements are allocated from the [slice allocator][glib-Memory-Slices], * which is more efficient than allocating elements individually. * * Note that most of the #FList 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 #FList. %NULL is considered to be * a valid, empty list so you simply set a #FList* to %NULL to initialize * it. * * To add elements, use f_list_append(), f_list_prepend(), * f_list_insert() and f_list_insert_sorted(). * * To visit all elements in the list, use a loop over the list: * |[ * FList *l; * for (l = list; l != NULL; l = l->next) * { * // do something with l->data * } * ]| * * To call a function for each element in the list, use f_list_foreach(). * * To loop over the list and modify it (e.g. remove a certain element) * a while loop is more appropriate, for example: * |[ * FList *l = list; * while (l != NULL) * { * FList *next = l->next; * if (should_be_removed (l)) * { * // possibly free l->data * list = f_list_delete_link (list, l); * } * l = next; * } * ]| * * To remove elements, use f_list_remove(). * * To navigate in a list, use f_list_first(), f_list_last(), * f_list_next(), f_list_previous(). * * To find elements in the list use f_list_nth(), f_list_nth_data(), * f_list_find() and f_list_find_custom(). * * To find the index of an element use f_list_position() and * f_list_index(). * * To free the entire list, use f_list_free() or f_list_free_full(). */ /** * FList: * @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][glib-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 #FList struct is used for each element in a doubly-linked list. **/ /** * f_list_previous: * @list: an element in a #FList * * A convenience macro to get the previous element in a #FList. * Note that it is considered perfectly acceptable to access * @list->previous directly. * * Returns: the previous element, or %NULL if there are no previous * elements **/ /** * f_list_next: * @list: an element in a #FList * * A convenience macro to get the next element in a #FList. * Note that it is considered perfectly acceptable to access * @list->next directly. * * Returns: the next element, or %NULL if there are no more elements **/ #define _f_list_alloc() ((FList *) malloc (sizeof (FList))) #define _f_list_alloc0() ((FList *) calloc (1, sizeof (FList))) #define _f_list_free1(list) free (list) /** * f_list_alloc: * * Allocates space for one #FList element. It is called by * f_list_append(), f_list_prepend(), f_list_insert() and * f_list_insert_sorted() and so is rarely used on its own. * * Returns: a pointer to the newly-allocated #FList element **/ FList * f_list_alloc (void) { return _f_list_alloc0 (); } /** * f_list_free: * @list: a #FList * * Frees all of the memory used by a #FList. * The freed elements are returned to the slice allocator. * * If list elements contain dynamically-allocated memory, you should * either use f_list_free_full() or free them manually first. */ void f_list_free (FList *list) { FList *n; while (list != NULL) { n = list->next; free (list); list = n; } } /** * f_list_free_1: * @list: a #FList element * * Frees one #FList element, but does not update links from the next and * previous elements in the list, so you should not call this function on an * element that is currently part of a list. * * It is usually used after f_list_remove_link(). */ /** * f_list_free1: * * Another name for f_list_free_1(). **/ void f_list_free_1 (FList *list) { _f_list_free1 (list); } /** * f_list_free_full: * @list: a pointer to a #FList * @free_func: the function to be called to free each element's data * * Convenience method, which frees all the memory used by a #FList, * and calls @free_func on every element's data. * * Since: 2.28 */ void f_list_free_full (FList *list, FDestroyNotify free_func) { f_list_foreach (list, (FFunc) free_func, NULL); f_list_free (list); } /** * f_list_append: * @list: a pointer to a #FList * @data: the data for the new element * * Adds a new element on to the end of the list. * * Note that the return value is the new start of the list, * if @list was empty; make sure you store the new value. * * f_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 use f_list_prepend() and reverse * the list with f_list_reverse() when all elements have been added. * * |[ * // Notice that these are initialized to the empty list. * FList *strinf_list = NULL, *number_list = NULL; * * // This is a list of strings. * strinf_list = f_list_append (strinf_list, "first"); * strinf_list = f_list_append (strinf_list, "second"); * * // This is a list of integers. * number_list = f_list_append (number_list, int_TO_POINTER (27)); * number_list = f_list_append (number_list, int_TO_POINTER (14)); * ]| * * Returns: either @list or the new start of the #FList if @list was %NULL */ FList * f_list_append (FList *list, void * data) { FList *new_list; FList *last; new_list = _f_list_alloc (); new_list->data = data; new_list->next = NULL; if (list) { last = f_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; } } /** * f_list_prepend: * @list: a pointer to a #FList, this must point to the top of the list * @data: the data for the new element * * Prepends a new element on to the start of the list. * * Note that the return value is the new start of the list, * which will have changed, so make sure you store the new value. * * |[ * // Notice that it is initialized to the empty list. * FList *list = NULL; * * list = f_list_prepend (list, "last"); * list = f_list_prepend (list, "first"); * ]| * * Do not use this function to prepend a new element to a different * element than the start of the list. Use f_list_insert_before() instead. * * Returns: a pointer to the newly prepended element, which is the new * start of the #FList */ FList * f_list_prepend (FList *list, void * data) { FList *new_list; new_list = _f_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; } /** * f_list_insert: * @list: a pointer to a #FList, this must point to the top of the list * @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 (possibly changed) start of the #FList */ FList * f_list_insert (FList *list, void * data, int position) { FList *new_list; FList *tmp_list; if (position < 0) return f_list_append (list, data); else if (position == 0) return f_list_prepend (list, data); tmp_list = f_list_nth (list, position); if (!tmp_list) return f_list_append (list, data); new_list = _f_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; } /** * f_list_insert_before: * @list: a pointer to a #FList, this must point to the top of the list * @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 (possibly changed) start of the #FList */ FList * f_list_insert_before (FList *list, FList *sibling, void * data) { if (!list) { list = f_list_alloc (); list->data = data; //if (sibling != NULL) return list; //g_return_val_if_fail (sibling == NULL, list); return list; } else if (sibling) { FList *node; node = _f_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 { FList *last; last = list; while (last->next) last = last->next; last->next = _f_list_alloc (); last->next->data = data; last->next->prev = last; last->next->next = NULL; return list; } } /** * f_list_concat: * @list1: a #FList, this must point to the top of the list * @list2: the #FList to add to the end of the first #FList, * this must point to the top of the list * * Adds the second #FList onto the end of the first #FList. * Note that the elements of the second #FList are not copied. * They are used directly. * * This function is for example used to move an element in the list. * The following example moves an element to the top of the list: * |[ * list = f_list_remove_link (list, llink); * list = f_list_concat (llink, list); * ]| * * Returns: the start of the new #FList, which equals @list1 if not %NULL */ FList * f_list_concat (FList *list1, FList *list2) { FList *tmp_list; if (list2) { tmp_list = f_list_last (list1); if (tmp_list) tmp_list->next = list2; else list1 = list2; list2->prev = tmp_list; } return list1; } static inline FList * _f_list_remove_link (FList *list, FList *link) { if (link == NULL) return list; if (link->prev) { if (link->prev->next == link) link->prev->next = link->next; //else printf ("corrupted double-linked list detected"); } if (link->next) { if (link->next->prev == link) link->next->prev = link->prev; else printf ("corrupted double-linked list detected"); } if (link == list) list = list->next; link->next = NULL; link->prev = NULL; return list; } /** * f_list_remove: * @list: a #FList, this must point to the top of the list * @data: the data of the element to remove * * Removes an element from a #FList. * If two elements contain the same data, only the first is removed. * If none of the elements contain the data, the #FList is unchanged. * * Returns: the (possibly changed) start of the #FList */ FList * f_list_remove (FList *list, const void * data) { FList *tmp; tmp = list; while (tmp) { if (tmp->data != data) tmp = tmp->next; else { list = _f_list_remove_link (list, tmp); _f_list_free1 (tmp); break; } } return list; } /** * f_list_remove_all: * @list: a #FList, this must point to the top of the list * @data: data to remove * * Removes all list nodes with data equal to @data. * Returns the new head of the list. Contrast with * f_list_remove() which removes only the first node * matching the given data. * * Returns: the (possibly changed) start of the #FList */ FList * f_list_remove_all (FList *list, const void * data) { FList *tmp = list; while (tmp) { if (tmp->data != data) tmp = tmp->next; else { FList *next = tmp->next; if (tmp->prev) tmp->prev->next = next; else list = next; if (next) next->prev = tmp->prev; _f_list_free1 (tmp); tmp = next; } } return list; } /** * f_list_remove_link: * @list: a #FList, this must point to the top of the list * @llink: an element in the #FList * * Removes an element from a #FList, 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. * * This function is for example used to move an element in the list * (see the example for f_list_concat()) or to remove an element in * the list before freeing its data: * |[ * list = f_list_remove_link (list, llink); * free_some_data_that_may_access_the_list_again (llink->data); * f_list_free (llink); * ]| * * Returns: the (possibly changed) start of the #FList */ FList * f_list_remove_link (FList *list, FList *llink) { return _f_list_remove_link (list, llink); } /** * f_list_delete_link: * @list: a #FList, this must point to the top of the list * @link_: node to delete from @list * * Removes the node link_ from the list and frees it. * Compare this to f_list_remove_link() which removes the node * without freeing it. * * Returns: the (possibly changed) start of the #FList */ FList * f_list_delete_link (FList *list, FList *link_) { list = _f_list_remove_link (list, link_); _f_list_free1 (link_); return list; } /** * f_list_copy: * @list: a #FList, this must point to the top of the list * * Copies a #FList. * * 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 f_list_copy_deep() if you need * to copy the data as well. * * Returns: the start of the new list that holds the same data as @list */ FList * f_list_copy (FList *list) { return f_list_copy_deep (list, NULL, NULL); } /** * f_list_copy_deep: * @list: a #FList, this must point to the top of the list * @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 #FList. * * In contrast with f_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 #FCopyFunc, takes two arguments, the data to be copied * and a @user_data 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 = f_list_copy_deep (list, (FCopyFunc) g_object_ref, NULL); * ]| * * And, to entirely free the new list, you could do: * |[ * f_list_free_full (another_list, g_object_unref); * ]| * * Returns: the start of the new list that holds a full copy of @list, * use f_list_free_full() to free it * * Since: 2.34 */ FList * f_list_copy_deep (FList *list, FCopyFunc func, void * user_data) { FList *new_list = NULL; if (list) { FList *last; new_list = _f_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 = _f_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; } /** * f_list_reverse: * @list: a #FList, this must point to the top of the list * * Reverses a #FList. * It simply switches the next and prev pointers of each element. * * Returns: the start of the reversed #FList */ FList * f_list_reverse (FList *list) { FList *last; last = NULL; while (list) { last = list; list = last->next; last->next = last->prev; last->prev = list; } return last; } /** * f_list_nth: * @list: a #FList, this must point to the top of the list * @n: the position of the element, counting from 0 * * Gets the element at the given position in a #FList. * * This iterates over the list until it reaches the @n-th position. If you * intend to iterate over every element, it is better to use a for-loop as * described in the #FList introduction. * * Returns: the element, or %NULL if the position is off * the end of the #FList */ FList * f_list_nth (FList *list, unsigned int n) { while ((n-- > 0) && list) list = list->next; return list; } /** * f_list_nth_prev: * @list: a #FList * @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 #FList */ FList * f_list_nth_prev (FList *list, unsigned int n) { while ((n-- > 0) && list) list = list->prev; return list; } /** * f_list_nth_data: * @list: a #FList, this must point to the top of the list * @n: the position of the element * * Gets the data of the element at the given position. * * This iterates over the list until it reaches the @n-th position. If you * intend to iterate over every element, it is better to use a for-loop as * described in the #FList introduction. * * Returns: the element's data, or %NULL if the position * is off the end of the #FList */ void * f_list_nth_data (FList *list, unsigned int n) { while ((n-- > 0) && list) list = list->next; return list ? list->data : NULL; } /** * f_list_find: * @list: a #FList, this must point to the top of the list * @data: the element data to find * * Finds the element in a #FList which contains the given data. * * Returns: the found #FList element, or %NULL if it is not found */ FList * f_list_find (FList *list, const void * data) { while (list) { if (list->data == data) break; list = list->next; } return list; } /** * f_list_find_custom: * @list: a #FList, this must point to the top of the list * @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 #FList, 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 #const void * arguments, * the #FList element's data as the first argument and the * given user data. * * Returns: the found #FList element, or %NULL if it is not found */ FList * f_list_find_custom (FList *list, const void * data, FCompareFunc func) { if (func == NULL) return list; //g_return_val_if_fail (func != NULL, list); while (list) { if (! func (list->data, data)) return list; list = list->next; } return NULL; } /** * f_list_position: * @list: a #FList, this must point to the top of the list * @llink: an element in the #FList * * Gets the position of the given element * in the #FList (starting from 0). * * Returns: the position of the element in the #FList, * or -1 if the element is not found */ int f_list_position (FList *list, FList *llink) { int i; i = 0; while (list) { if (list == llink) return i; i++; list = list->next; } return -1; } /** * f_list_index: * @list: a #FList, this must point to the top of the list * @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 */ int f_list_index (FList *list, const void * data) { int i; i = 0; while (list) { if (list->data == data) return i; i++; list = list->next; } return -1; } /** * f_list_last: * @list: any #FList element * * Gets the last element in a #FList. * * Returns: the last element in the #FList, * or %NULL if the #FList has no elements */ FList * f_list_last (FList *list) { if (list) { while (list->next) list = list->next; } return list; } /** * f_list_first: * @list: any #FList element * * Gets the first element in a #FList. * * Returns: the first element in the #FList, * or %NULL if the #FList has no elements */ FList * f_list_first (FList *list) { if (list) { while (list->prev) list = list->prev; } return list; } /** * f_list_length: * @list: a #FList, this must point to the top of the list * * Gets the number of elements in a #FList. * * This function iterates over the whole list to count its elements. * Use a #GQueue instead of a FList if you regularly need the number * of items. To check whether the list is non-empty, it is faster to check * @list against %NULL. * * Returns: the number of elements in the #FList */ unsigned int f_list_length (FList *list) { unsigned int length; length = 0; while (list) { length++; list = list->next; } return length; } /** * f_list_foreach: * @list: a #FList, this must point to the top of the list * @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 #FList. */ /** * FFunc: * @data: the element's data * @user_data: user data passed to f_list_foreach() or g_slist_foreach() * * Specifies the type of functions passed to f_list_foreach() and * g_slist_foreach(). */ void f_list_foreach (FList *list, FFunc func, void * user_data) { while (list) { FList *next = list->next; (*func) (list->data, user_data); list = next; } } static FList* f_list_insert_sorted_real (FList *list, void * data, FFunc func, void * user_data) { FList *tmp_list = list; FList *new_list; int cmp; if (func == NULL) return list; //g_return_val_if_fail (func != NULL, list); if (!list) { new_list = _f_list_alloc0 (); new_list->data = data; return new_list; } cmp = ((FCompareDataFunc) func) (data, tmp_list->data, user_data); while ((tmp_list->next) && (cmp > 0)) { tmp_list = tmp_list->next; cmp = ((FCompareDataFunc) func) (data, tmp_list->data, user_data); } new_list = _f_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; } /** * f_list_insert_sorted: * @list: a pointer to a #FList, this must point to the top of the * already sorted list * @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. * * If you are adding many new elements to a list, and the number of * new elements is much larger than the length of the list, use * f_list_prepend() to add the new items and sort the list afterwards * with f_list_sort(). * * Returns: the (possibly changed) start of the #FList */ FList * f_list_insert_sorted (FList *list, void * data, FCompareFunc func) { return f_list_insert_sorted_real (list, data, (FFunc) func, NULL); } /** * f_list_insert_sorted_with_data: * @list: a pointer to a #FList, this must point to the top of the * already sorted list * @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. * * If you are adding many new elements to a list, and the number of * new elements is much larger than the length of the list, use * f_list_prepend() to add the new items and sort the list afterwards * with f_list_sort(). * * Returns: the (possibly changed) start of the #FList * * Since: 2.10 */ FList * f_list_insert_sorted_with_data (FList *list, void * data, FCompareDataFunc func, void * user_data) { return f_list_insert_sorted_real (list, data, (FFunc) func, user_data); } static FList * f_list_sort_merge (FList *l1, FList *l2, FFunc compare_func, void * user_data) { FList list, *l, *lprev; int cmp; l = &list; lprev = NULL; while (l1 && l2) { cmp = ((FCompareDataFunc) 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 FList * f_list_sort_real (FList *list, FFunc compare_func, void * user_data) { FList *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 f_list_sort_merge (f_list_sort_real (list, compare_func, user_data), f_list_sort_real (l2, compare_func, user_data), compare_func, user_data); } /** * f_list_sort: * @list: a #FList, this must point to the top of the list * @compare_func: the comparison function used to sort the #FList. * This function is passed the data from 2 elements of the #FList * 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 #FList using the given comparison function. The algorithm * used is a stable sort. * * Returns: the (possibly changed) start of the #FList */ /** * FCompareFunc: * @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 */ FList * f_list_sort (FList *list, FCompareFunc compare_func) { return f_list_sort_real (list, (FFunc) compare_func, NULL); } /** * f_list_sort_with_data: * @list: a #FList, this must point to the top of the list * @compare_func: comparison function * @user_data: user data to pass to comparison function * * Like f_list_sort(), but the comparison function accepts * a user data argument. * * Returns: the (possibly changed) start of the #FList */ /** * FCompareDataFunc: * @a: a value * @b: a value to compare with * @user_data: user data * * 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 */ FList * f_list_sort_with_data (FList *list, FCompareDataFunc compare_func, void * user_data) { return f_list_sort_real (list, (FFunc) compare_func, user_data); }