adns/dlist.h

   1 /*
   2  * dlist.h
   3  * - macros for handling doubly linked lists
   4  */
   5 /*
   6  *  This file is
   7  *    Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
   8  *
   9  *  It is part of adns, which is
  10  *    Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
  11  *    Copyright (C) 1999 Tony Finch <dot@dotat.at>
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License as published by
  15  *  the Free Software Foundation; either version 2, or (at your option)
  16  *  any later version.
  17  *
  18  *  This program is distributed in the hope that it will be useful,
  19  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  *  GNU General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License
  24  *  along with this program; if not, write to the Free Software Foundation,
  25  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  26  *
  27  *  $Id: dlist.h 17804 2004-09-15 18:32:22Z androsyn $
  28  */
  29
  30 #ifndef ADNS_DLIST_H_INCLUDED
  31 #define ADNS_DLIST_H_INCLUDED
  32
  33 #define ADNS_LIST_INIT(list) ((list).head= (list).tail= 0)
  34 #define LINK_INIT(link) ((link).next= (link).back= 0)
  35
  36 #define LIST_UNLINK_PART(list,node,part) \
  37   do { \
  38     if ((node)->part back) (node)->part back->part next= (node)->part next; \
  39       else                                  (list).head= (node)->part next; \
  40     if ((node)->part next) (node)->part next->part back= (node)->part back; \
  41       else                                  (list).tail= (node)->part back; \
  42   } while(0)
  43
  44 #define LIST_LINK_TAIL_PART(list,node,part) \
  45   do { \
  46     (node)->part next= 0; \
  47     (node)->part back= (list).tail; \
  48     if ((list).tail) (list).tail->part next= (node); else (list).head= (node); \
  49     (list).tail= (node); \
  50   } while(0)
  51
  52 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
  53 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
  54
  55 #endif