[thirdparty/systemd.git] / src / shared / list.h

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

#pragma once

/***
  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 Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser 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_JUST_US(name,item)                                         \
        (!(item)->name##_prev && !(item)->name##_next)                  \

#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))

#define LIST_FOREACH_BEFORE(name,i,p)                                   \
        for ((i) = (p)->name##_prev; (i); (i) = (i)->name##_prev)

#define LIST_FOREACH_AFTER(name,i,p)                                    \
        for ((i) = (p)->name##_next; (i); (i) = (i)->name##_next)
Commit	Line	Data
03467c88	1	/-- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil --/
60918275	2
c2f1db8f	3	#pragma once
60918275	4
a7334b09 LP	5	/***
	6	This file is part of systemd.
	7
	8	Copyright 2010 Lennart Poettering
	9
	10	systemd is free software; you can redistribute it and/or modify it
5430f7f2 LP	11	under the terms of the GNU Lesser General Public License as published by
5430f7f2 LP	12	the Free Software Foundation; either version 2.1 of the License, or
a7334b09 LP	13	(at your option) any later version.
	14
	15	systemd is distributed in the hope that it will be useful, but
	16	WITHOUT ANY WARRANTY; without even the implied warranty of
	17	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
5430f7f2	18	Lesser General Public License for more details.
a7334b09	19
5430f7f2	20	You should have received a copy of the GNU Lesser General Public License
a7334b09 LP	21	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	22	***/
	23
60918275 LP	24	/* The head of the linked list. Use this in the structure that shall
	25	* contain the head of the linked list */
	26	#define LIST_HEAD(t,name) \
034c6ed7	27	t *name
60918275 LP	28
60918275 LP	29	/* The pointers in the linked list's items. Use this in the item structure */
034c6ed7 LP	30	#define LIST_FIELDS(t,name) \
034c6ed7 LP	31	t name##_next, name##_prev
60918275 LP	32
60918275 LP	33	/* Initialize the list's head */
034c6ed7	34	#define LIST_HEAD_INIT(t,head) \
60918275	35	do { \
034c6ed7	36	(head) = NULL; } \
60918275 LP	37	while(false)
	38
	39	/* Initialize a list item */
034c6ed7	40	#define LIST_INIT(t,name,item) \
60918275 LP	41	do { \
	42	t *_item = (item); \
	43	assert(_item); \
034c6ed7	44	_item->name##_prev = _item->name##_next = NULL; \
60918275 LP	45	} while(false)
	46
	47	/* Prepend an item to the list */
034c6ed7	48	#define LIST_PREPEND(t,name,head,item) \
60918275 LP	49	do { \
	50	t *_head = &(head), _item = (item); \
	51	assert(_item); \
034c6ed7 LP	52	if ((_item->name##_next = *_head)) \
	53	_item->name##_next->name##_prev = _item; \
	54	_item->name##_prev = NULL; \
60918275 LP	55	*_head = _item; \
	56	} while(false)
	57
	58	/* Remove an item from the list */
034c6ed7	59	#define LIST_REMOVE(t,name,head,item) \
60918275 LP	60	do { \
	61	t *_head = &(head), _item = (item); \
	62	assert(_item); \
034c6ed7 LP	63	if (_item->name##_next) \
	64	_item->name##_next->name##_prev = _item->name##_prev; \
	65	if (_item->name##_prev) \
	66	_item->name##_prev->name##_next = _item->name##_next; \
60918275 LP	67	else { \
60918275 LP	68	assert(*_head == _item); \
034c6ed7	69	*_head = _item->name##_next; \
60918275	70	} \
034c6ed7	71	_item->name##_next = _item->name##_prev = NULL; \
60918275 LP	72	} while(false)
	73
	74	/* Find the head of the list */
034c6ed7	75	#define LIST_FIND_HEAD(t,name,item,head) \
60918275	76	do { \
034c6ed7 LP	77	t *_item = (item); \
034c6ed7 LP	78	assert(_item); \
95e26a69	79	while (_item->name##_prev) \
034c6ed7 LP	80	_item = _item->name##_prev; \
	81	(head) = _item; \
	82	} while (false)
	83
	84	/* Find the head of the list */
	85	#define LIST_FIND_TAIL(t,name,item,tail) \
	86	do { \
	87	t *_item = (item); \
	88	assert(_item); \
	89	while (_item->name##_next) \
	90	_item = _item->name##_next; \
	91	(tail) = _item; \
60918275 LP	92	} while (false)
	93
	94	/* Insert an item after another one (a = where, b = what) */
034c6ed7	95	#define LIST_INSERT_AFTER(t,name,head,a,b) \
60918275 LP	96	do { \
	97	t *_head = &(head), _a = (a), *_b = (b); \
	98	assert(_b); \
	99	if (!_a) { \
034c6ed7 LP	100	if ((_b->name##_next = *_head)) \
	101	_b->name##_next->name##_prev = _b; \
	102	_b->name##_prev = NULL; \
60918275 LP	103	*_head = _b; \
60918275 LP	104	} else { \
034c6ed7 LP	105	if ((_b->name##_next = _a->name##_next)) \
	106	_b->name##_next->name##_prev = _b; \
	107	_b->name##_prev = _a; \
	108	_a->name##_next = _b; \
60918275 LP	109	} \
	110	} while(false)
	111
6210e7fc LP	112	#define LIST_JUST_US(name,item) \
	113	(!(item)->name##_prev && !(item)->name##_next) \
	114
034c6ed7 LP	115	#define LIST_FOREACH(name,i,head) \
034c6ed7 LP	116	for ((i) = (head); (i); (i) = (i)->name##_next)
60918275	117
034c6ed7 LP	118	#define LIST_FOREACH_SAFE(name,i,n,head) \
034c6ed7 LP	119	for ((i) = (head); (i) && (((n) = (i)->name##_next), 1); (i) = (n))
60918275	120
e04aad61 LP	121	#define LIST_FOREACH_BEFORE(name,i,p) \
	122	for ((i) = (p)->name##_prev; (i); (i) = (i)->name##_prev)
	123
	124	#define LIST_FOREACH_AFTER(name,i,p) \
	125	for ((i) = (p)->name##_next; (i); (i) = (i)->name##_next)