/*
 * Copyright (C) 1997-2002, 2004, 2006, 2007, 2011-2013, 2016  Internet Systems
 * Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#ifndef DLZ_LIST_H
#define DLZ_LIST_H 1

#define DLZ_LIST(type)             \
	struct {                   \
		type *head, *tail; \
	}
#define DLZ_LIST_INIT(list)         \
	do {                        \
		(list).head = NULL; \
		(list).tail = NULL; \
	} while (0)

#define DLZ_LINK(type)             \
	struct {                   \
		type *prev, *next; \
	}
#define DLZ_LINK_INIT(elt, link)                 \
	do {                                     \
		(elt)->link.prev = (void *)(-1); \
		(elt)->link.next = (void *)(-1); \
	} while (0)

#define DLZ_LIST_HEAD(list) ((list).head)
#define DLZ_LIST_TAIL(list) ((list).tail)

#define DLZ_LIST_APPEND(list, elt, link)                \
	do {                                            \
		if ((list).tail != NULL)                \
			(list).tail->link.next = (elt); \
		else                                    \
			(list).head = (elt);            \
		(elt)->link.prev = (list).tail;         \
		(elt)->link.next = NULL;                \
		(list).tail = (elt);                    \
	} while (0)

#define DLZ_LIST_PREV(elt, link) ((elt)->link.prev)
#define DLZ_LIST_NEXT(elt, link) ((elt)->link.next)

#endif /* DLZ_LIST_H */
