1/*
2   Unix SMB/Netbios implementation.
3   Version 1.9.
4   some simple double linked list macros
5   Copyright (C) Andrew Tridgell 1998
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 2 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, write to the Free Software
19   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20*/
21
22/* To use these macros you must have a structure containing a next and
23   prev pointer */
24
25
26/* hook into the front of the list */
27#define DLIST_ADD(list, p) \
28{ \
29        if (!(list)) { \
30		(list) = (p); \
31		(p)->next = (p)->prev = NULL; \
32	} else { \
33		(list)->prev = (p); \
34		(p)->next = (list); \
35		(p)->prev = NULL; \
36		(list) = (p); \
37	}\
38}
39
40
41/* remove an element from a list */
42#define DLIST_REMOVE(list, p) \
43{ \
44	if ((p) == (list)) { \
45		(list) = (p)->next; \
46		if (list) (list)->prev = NULL; \
47	} else { \
48		(p)->prev->next = (p)->next; \
49		if ((p)->next) (p)->next->prev = (p)->prev; \
50	} \
51}
52
53/* promote an element to the top of the list */
54#define DLIST_PROMOTE(list, p) \
55          DLIST_REMOVE(list, p) \
56          DLIST_ADD(list, p)
57