tinc/lib/list.c
2019-08-26 13:44:37 +02:00

186 lines
3.3 KiB
C

/*
list.c -- functions to deal with double linked lists
Copyright (C) 2000-2005 Ivo Timmermans
2000-2006 Guus Sliepen <guus@tinc-vpn.org>
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 1452 2006-04-26 13:52:58Z guus $
*/
#include "system.h"
#include "list.h"
#include "xalloc.h"
/* (De)constructors */
list_t *list_alloc(list_action_t delete)
{
list_t *list;
list = xmalloc_and_zero(sizeof(list_t));
list->delete = delete;
return list;
}
void list_free(list_t *list)
{
free(list);
}
list_node_t *list_alloc_node(void)
{
return xmalloc_and_zero(sizeof(list_node_t));
}
void list_free_node(list_t *list, list_node_t *node)
{
if(node->data && list->delete)
list->delete(node->data);
free(node);
}
/* Insertion and deletion */
list_node_t *list_insert_head(list_t *list, void *data)
{
list_node_t *node;
node = list_alloc_node();
node->data = data;
node->prev = NULL;
node->next = list->head;
list->head = node;
if(node->next)
node->next->prev = node;
else
list->tail = node;
list->count++;
return node;
}
list_node_t *list_insert_tail(list_t *list, void *data)
{
list_node_t *node;
node = list_alloc_node();
node->data = data;
node->next = NULL;
node->prev = list->tail;
list->tail = node;
if(node->prev)
node->prev->next = node;
else
list->head = node;
list->count++;
return node;
}
void list_unlink_node(list_t *list, list_node_t *node)
{
if(node->prev)
node->prev->next = node->next;
else
list->head = node->next;
if(node->next)
node->next->prev = node->prev;
else
list->tail = node->prev;
list->count--;
}
void list_delete_node(list_t *list, list_node_t *node)
{
list_unlink_node(list, node);
list_free_node(list, node);
}
void list_delete_head(list_t *list)
{
list_delete_node(list, list->head);
}
void list_delete_tail(list_t *list)
{
list_delete_node(list, list->tail);
}
/* Head/tail lookup */
void *list_get_head(list_t *list)
{
if(list->head)
return list->head->data;
else
return NULL;
}
void *list_get_tail(list_t *list)
{
if(list->tail)
return list->tail->data;
else
return NULL;
}
/* Fast list deletion */
void list_delete_list(list_t *list)
{
list_node_t *node, *next;
for(node = list->head; node; node = next) {
next = node->next;
list_free_node(list, node);
}
list_free(list);
}
/* Traversing */
void list_foreach_node(list_t *list, list_action_node_t action)
{
list_node_t *node, *next;
for(node = list->head; node; node = next) {
next = node->next;
action(node);
}
}
void list_foreach(list_t *list, list_action_t action)
{
list_node_t *node, *next;
for(node = list->head; node; node = next) {
next = node->next;
if(node->data)
action(node->data);
}
}