+/*
+ list.c -- functions to deal with double linked lists
+ Copyright (C) 2000 Ivo Timmermans <itimmermans@bigfoot.com>
+ 2000 Guus Sliepen <guus@sliepen.warande.net>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ $Id: list.c,v 1.1 2000/10/20 16:44:32 zarq Exp $
+*/
+
+#include "config.h"
+
+#include <string.h>
+
+#include <error.h>
+#include <list.h>
+#include <xalloc.h>
+
+#include <system.h>
+
+/*
+ list_new
+
+ Initialize a new list.
+*/
+list_t *list_new(void)
+{
+ list_t *list;
+
+ list = xmalloc_and_zero(sizeof(list_t));
+ return list;
+}
+
+/*
+ list_delete
+
+ Delete the element pointed to by idx from the list.
+*/
+list_node_t *list_delete(list_t *list, list_node_t *idx)
+{
+ list_node_t *res;
+
+ if(!list)
+ return NULL;
+ if(!idx)
+ return NULL;
+
+ if(list->callbacks->delete != NULL)
+ if(list->callbacks->delete(idx->data))
+ error(ERR_WARNING, N_("List callback[delete] failed for %08lx - freeing anyway"), idx->data);
+
+ free(idx->data);
+
+ if(idx->prev == NULL)
+ /* First element in list */
+ {
+ res = idx->next;
+ list->head = idx->next;
+ }
+ if(idx->next == NULL)
+ /* Last element in list */
+ {
+ res = NULL;
+ list->tail = idx->prev;
+ }
+ if(idx->prev != NULL && idx->next != NULL)
+ /* Neither first nor last element */
+ {
+ idx->prev->next = idx->next;
+ idx->next->prev = idx->prev;
+ }
+ if(list->head == NULL)
+ list->tail = NULL;
+ else
+ if(list->tail == NULL)
+ list->head = NULL;
+ free(idx);
+ return res;
+}
+
+/*
+ list_forall_nodes
+
+ Call function() on each element in the list. If this function
+ returns non-zero, the element will be removed from the list.
+*/
+void list_forall_nodes(list_t *list, int (*function)(void *data))
+{
+ list_node_t *p;
+ int res;
+
+ if(!list) /* no list given */
+ return;
+ if(!function) /* no function given */
+ return;
+ if(!list->head) /* list is empty */
+ return;
+ for(p = list->head; p != NULL; p = p->next)
+ {
+ res = function(p->data);
+ if(res != 0)
+ p = list_delete(list, p);
+ }
+}
+
+/*
+ list_destroy
+
+ Free all datastructures contained in this list. It uses the delete
+ callback for this list to free each element.
+*/
+void list_destroy(list_t *list)
+{
+ if(!list)
+ return;
+ list_destroy_nodes(list);
+ free(list);
+}
+
+/*
+ list_append
+
+ Append a new node to the list that points to data.
+*/
+list_append(list_t *list, void *data)
+{
+ list_node_t *n;
+
+ n = xmalloc_and_zero(sizeof(list_node_t));
+ n->data = data;
+ n->prev = list->tail;
+ list->tail->next = n;
+ list->tail = n;
+}