michael@0: /*	$NetBSD: list.h,v 1.2 2004/05/20 19:51:55 christos Exp $	*/
michael@0: 
michael@0: /*
michael@0:  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
michael@0:  * Copyright (c) 1997,1999 by Internet Software Consortium.
michael@0:  *
michael@0:  * Permission to use, copy, modify, and distribute this software for any
michael@0:  * purpose with or without fee is hereby granted, provided that the above
michael@0:  * copyright notice and this permission notice appear in all copies.
michael@0:  *
michael@0:  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
michael@0:  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
michael@0:  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
michael@0:  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
michael@0:  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
michael@0:  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
michael@0:  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
michael@0:  */
michael@0: 
michael@0: /*
michael@0:  * This version of this file is derived from Android 2.3 "Gingerbread",
michael@0:  * which contains uncredited changes by Android/Google developers.  It has
michael@0:  * been modified in 2011 for use in the Android build of Mozilla Firefox by
michael@0:  * Mozilla contributors (including Michael Edwards <m.k.edwards@gmail.com>,
michael@0:  * and Steve Workman <sjhworkman@gmail.com>).
michael@0:  * These changes are offered under the same license as the original NetBSD
michael@0:  * file, whose copyright and license are unchanged above.
michael@0:  */
michael@0: 
michael@0: #ifndef LIST_H
michael@0: #define LIST_H 1
michael@0: #include "assertions.h"
michael@0: 
michael@0: #define LIST(type) struct { type *head, *tail; }
michael@0: #define INIT_LIST(list) \
michael@0: 	do { (list).head = NULL; (list).tail = NULL; } while (/*CONSTCOND*/0)
michael@0: 
michael@0: #define LINK(type) struct { type *prev, *next; }
michael@0: #define INIT_LINK_TYPE(elt, link, type) \
michael@0: 	do { \
michael@0: 		(elt)->link.prev = (type *)(-1); \
michael@0: 		(elt)->link.next = (type *)(-1); \
michael@0: 	} while (/*CONSTCOND*/0)
michael@0: #define INIT_LINK(elt, link) \
michael@0: 	INIT_LINK_TYPE(elt, link, void)
michael@0: #define LINKED(elt, link) ((void *)((elt)->link.prev) != (void *)(-1))
michael@0: 
michael@0: #define HEAD(list) ((list).head)
michael@0: #define TAIL(list) ((list).tail)
michael@0: #define EMPTY(list) ((list).head == NULL)
michael@0: 
michael@0: #define PREPEND(list, elt, link) \
michael@0: 	do { \
michael@0: 		INSIST(!LINKED(elt, link));\
michael@0: 		if ((list).head != NULL) \
michael@0: 			(list).head->link.prev = (elt); \
michael@0: 		else \
michael@0: 			(list).tail = (elt); \
michael@0: 		(elt)->link.prev = NULL; \
michael@0: 		(elt)->link.next = (list).head; \
michael@0: 		(list).head = (elt); \
michael@0: 	} while (/*CONSTCOND*/0)
michael@0: 
michael@0: #define APPEND(list, elt, link) \
michael@0: 	do { \
michael@0: 		INSIST(!LINKED(elt, link));\
michael@0: 		if ((list).tail != NULL) \
michael@0: 			(list).tail->link.next = (elt); \
michael@0: 		else \
michael@0: 			(list).head = (elt); \
michael@0: 		(elt)->link.prev = (list).tail; \
michael@0: 		(elt)->link.next = NULL; \
michael@0: 		(list).tail = (elt); \
michael@0: 	} while (/*CONSTCOND*/0)
michael@0: 
michael@0: #define UNLINK_TYPE(list, elt, link, type) \
michael@0: 	do { \
michael@0: 		INSIST(LINKED(elt, link));\
michael@0: 		if ((elt)->link.next != NULL) \
michael@0: 			(elt)->link.next->link.prev = (elt)->link.prev; \
michael@0: 		else \
michael@0: 			(list).tail = (elt)->link.prev; \
michael@0: 		if ((elt)->link.prev != NULL) \
michael@0: 			(elt)->link.prev->link.next = (elt)->link.next; \
michael@0: 		else \
michael@0: 			(list).head = (elt)->link.next; \
michael@0: 		INIT_LINK_TYPE(elt, link, type); \
michael@0: 	} while (/*CONSTCOND*/0)
michael@0: #define UNLINK(list, elt, link) \
michael@0: 	UNLINK_TYPE(list, elt, link, void)
michael@0: 
michael@0: #define PREV(elt, link) ((elt)->link.prev)
michael@0: #define NEXT(elt, link) ((elt)->link.next)
michael@0: 
michael@0: #define INSERT_BEFORE(list, before, elt, link) \
michael@0: 	do { \
michael@0: 		INSIST(!LINKED(elt, link));\
michael@0: 		if ((before)->link.prev == NULL) \
michael@0: 			PREPEND(list, elt, link); \
michael@0: 		else { \
michael@0: 			(elt)->link.prev = (before)->link.prev; \
michael@0: 			(before)->link.prev = (elt); \
michael@0: 			(elt)->link.prev->link.next = (elt); \
michael@0: 			(elt)->link.next = (before); \
michael@0: 		} \
michael@0: 	} while (/*CONSTCOND*/0)
michael@0: 
michael@0: #define INSERT_AFTER(list, after, elt, link) \
michael@0: 	do { \
michael@0: 		INSIST(!LINKED(elt, link));\
michael@0: 		if ((after)->link.next == NULL) \
michael@0: 			APPEND(list, elt, link); \
michael@0: 		else { \
michael@0: 			(elt)->link.next = (after)->link.next; \
michael@0: 			(after)->link.next = (elt); \
michael@0: 			(elt)->link.next->link.prev = (elt); \
michael@0: 			(elt)->link.prev = (after); \
michael@0: 		} \
michael@0: 	} while (/*CONSTCOND*/0)
michael@0: 
michael@0: #define ENQUEUE(list, elt, link) APPEND(list, elt, link)
michael@0: #define DEQUEUE(list, elt, link) UNLINK(list, elt, link)
michael@0: 
michael@0: #endif /* LIST_H */