systemd/list.h
2010-02-03 13:03:47 +01:00

120 lines
6.0 KiB
C

/*-*- Mode: C; c-basic-offset: 8 -*-*/
#ifndef foolisthfoo
#define foolisthfoo
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd 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.
systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/
/* The head of the linked list. Use this in the structure that shall
* contain the head of the linked list */
#define LIST_HEAD(t,name) \
t *name
/* The pointers in the linked list's items. Use this in the item structure */
#define LIST_FIELDS(t,name) \
t *name##_next, *name##_prev
/* Initialize the list's head */
#define LIST_HEAD_INIT(t,head) \
do { \
(head) = NULL; } \
while(false)
/* Initialize a list item */
#define LIST_INIT(t,name,item) \
do { \
t *_item = (item); \
assert(_item); \
_item->name##_prev = _item->name##_next = NULL; \
} while(false)
/* Prepend an item to the list */
#define LIST_PREPEND(t,name,head,item) \
do { \
t **_head = &(head), *_item = (item); \
assert(_item); \
if ((_item->name##_next = *_head)) \
_item->name##_next->name##_prev = _item; \
_item->name##_prev = NULL; \
*_head = _item; \
} while(false)
/* Remove an item from the list */
#define LIST_REMOVE(t,name,head,item) \
do { \
t **_head = &(head), *_item = (item); \
assert(_item); \
if (_item->name##_next) \
_item->name##_next->name##_prev = _item->name##_prev; \
if (_item->name##_prev) \
_item->name##_prev->name##_next = _item->name##_next; \
else { \
assert(*_head == _item); \
*_head = _item->name##_next; \
} \
_item->name##_next = _item->name##_prev = NULL; \
} while(false)
/* Find the head of the list */
#define LIST_FIND_HEAD(t,name,item,head) \
do { \
t *_item = (item); \
assert(_item); \
while ((_item->name##_prev) \
_item = _item->name##_prev; \
(head) = _item; \
} while (false)
/* Find the head of the list */
#define LIST_FIND_TAIL(t,name,item,tail) \
do { \
t *_item = (item); \
assert(_item); \
while (_item->name##_next) \
_item = _item->name##_next; \
(tail) = _item; \
} while (false)
/* Insert an item after another one (a = where, b = what) */
#define LIST_INSERT_AFTER(t,name,head,a,b) \
do { \
t **_head = &(head), *_a = (a), *_b = (b); \
assert(_b); \
if (!_a) { \
if ((_b->name##_next = *_head)) \
_b->name##_next->name##_prev = _b; \
_b->name##_prev = NULL; \
*_head = _b; \
} else { \
if ((_b->name##_next = _a->name##_next)) \
_b->name##_next->name##_prev = _b; \
_b->name##_prev = _a; \
_a->name##_next = _b; \
} \
} while(false)
#define LIST_FOREACH(name,i,head) \
for ((i) = (head); (i); (i) = (i)->name##_next)
#define LIST_FOREACH_SAFE(name,i,n,head) \
for ((i) = (head); (i) && (((n) = (i)->name##_next), 1); (i) = (n))
#endif