source/ubi_dLinkList.h

   1 #ifndef ubi_dLinkList_H
   2 #define ubi_dLinkList_H
   3 /* ========================================================================== **
   4  *                              ubi_dLinkList.h
   5  *
   6  *  Copyright (C) 1997 by Christopher R. Hertel
   7  *
   8  *  Email: crh@ubiqx.mn.org
   9  * -------------------------------------------------------------------------- **
  10  *  This module implements simple doubly-linked lists.
  11  * -------------------------------------------------------------------------- **
  12  *
  13  *  This library is free software; you can redistribute it and/or
  14  *  modify it under the terms of the GNU Library General Public
  15  *  License as published by the Free Software Foundation; either
  16  *  version 2 of the License, or (at your option) any later version.
  17  *
  18  *  This library 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 GNU
  21  *  Library General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU Library General Public
  24  *  License along with this library; if not, write to the Free
  25  *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  26  *
  27  * -------------------------------------------------------------------------- **
  28  *
  29  * Revision 0.3  1997/10/15 03:04:31  crh
  30  * Added some handy type casting to the macros.  Added AddHere and RemThis
  31  * macros.
  32  *
  33  * Revision 0.2  1997/10/08 03:08:16  crh
  34  * Fixed a few forgotten link-ups in Insert(), and fixed the AddHead()
  35  * macro, which was passing the wrong value for <After> to Insert().
  36  *
  37  * Revision 0.1  1997/10/07 04:34:38  crh
  38  * Initial Revision.
  39  *
  40  *
  41  * ========================================================================== **
  42  */
  43
  44 #include <stdlib.h>
  45
  46
  47 /* ========================================================================== **
  48  * Typedefs...
  49  *
  50  *  ubi_dlNode    - This is the basic node structure.
  51  *  ubi_dlNodePtr - Pointer to a node.
  52  *  ubi_dlList    - This is the list header structure.
  53  *  ubi_dlListPtr - Pointer to a List (i.e., a list header structure).
  54  *
  55  */
  56
  57 typedef struct ubi_dlListNode
  58   {
  59   struct ubi_dlListNode *Next;
  60   struct ubi_dlListNode *Prev;
  61   } ubi_dlNode;
  62
  63 typedef ubi_dlNode *ubi_dlNodePtr;
  64
  65 typedef struct
  66   {
  67   ubi_dlNodePtr Head;
  68   ubi_dlNodePtr Tail;
  69   unsigned long count;
  70   } ubi_dlList;
  71
  72 typedef ubi_dlList *ubi_dlListPtr;
  73
  74 /* ========================================================================== **
  75  * Macros...
  76  *
  77  *  ubi_dlAddHead - Add a new node at the head of the list.
  78  *  ubi_dlAddTail - Add a new node at the tail of the list.
  79  *  ubi_dlAddHere - Add a node following the given node.
  80  *  ubi_dlRemHead - Remove the node at the head of the list, if any.
  81  *  ubi_dlRemTail - Remove the node at the tail of the list, if any.
  82  *  ubi_dlRemThis - Remove the indicated node.
  83  *  ubi_dlFirst   - Return a pointer to the first node in the list, if any.
  84  *  ubi_dlLast    - Return a pointer to the last node in the list, if any.
  85  *  ubi_dlNext    - Given a node, return a pointer to the next node.
  86  *  ubi_dlPrev    - Given a node, return a pointer to the previous node.
  87  *
  88  *  Note that all of these provide type casting of the parameters.  The
  89  *  Add and Rem macros are nothing more than nice front-ends to the
  90  *  Insert and Remove operations.
  91  *
  92  */
  93
  94 #define ubi_dlAddHead( L, N ) \
  95         ubi_dlInsert( (ubi_dlListPtr)(L), (ubi_dlNodePtr)(N), NULL )
  96
  97 #define ubi_dlAddTail( L, N ) \
  98         ubi_dlInsert( (ubi_dlListPtr)(L), \
  99                       (ubi_dlNodePtr)(N), \
 100                     (((ubi_dlListPtr)(L))->Tail) )
 101
 102 #define ubi_dlAddHere( L, N, P ) \
 103         ubi_dlInsert( (ubi_dlListPtr)(L), \
 104                       (ubi_dlNodePtr)(N), \
 105                       (ubi_dlNodePtr)(P) )
 106
 107 #define ubi_dlRemHead( L ) ubi_dlRemove( (ubi_dlListPtr)(L), \
 108                                          (((ubi_dlListPtr)(L))->Head) )
 109
 110 #define ubi_dlRemTail( L ) ubi_dlRemove( (ubi_dlListPtr)(L), \
 111                                          (((ubi_dlListPtr)(L))->Tail) )
 112
 113 #define ubi_dlRemThis( L, N ) ubi_dlRemove( (ubi_dlListPtr)(L), \
 114                                             (ubi_dlNodePtr)(N) )
 115
 116 #define ubi_dlFirst( L ) (((ubi_dlListPtr)(L))->Head)
 117
 118 #define ubi_dlLast( L )  (((ubi_dlListPtr)(L))->Tail)
 119
 120 #define ubi_dlNext( N )  (((ubi_dlNodePtr)(N))->Next)
 121
 122 #define ubi_dlPrev( N )  (((ubi_dlNodePtr)(N))->Prev)
 123
 124
 125 /* ========================================================================== **
 126  * Function prototypes...
 127  */
 128
 129 ubi_dlListPtr ubi_dlInitList( ubi_dlListPtr ListPtr );
 130   /* ------------------------------------------------------------------------ **
 131    * Initialize a doubly-linked list header.
 132    *
 133    *  Input:  ListPtr - A pointer to the list structure that is to be
 134    *                    initialized for use.
 135    *
 136    *  Output: A pointer to the initialized list header (i.e., same as
 137    *          <ListPtr>).
 138    *
 139    * ------------------------------------------------------------------------ **
 140    */
 141
 142 ubi_dlNodePtr ubi_dlInsert( ubi_dlListPtr ListPtr,
 143                             ubi_dlNodePtr New,
 144                             ubi_dlNodePtr After );
 145   /* ------------------------------------------------------------------------ **
 146    * Insert a new node into the list.
 147    *
 148    *  Input:  ListPtr - A pointer to the list into which the node is to
 149    *                    be inserted.
 150    *          New     - Pointer to the new node.
 151    *          After   - NULL, or a pointer to a node that is already in the
 152    *                    list.
 153    *                    If NULL, then <New> will be added at the head of the
 154    *                    list, else it will be added following <After>.
 155    *
 156    *  Output: A pointer to the node that was inserted into the list (i.e.,
 157    *          the same as <New>).
 158    *
 159    * ------------------------------------------------------------------------ **
 160    */
 161
 162 ubi_dlNodePtr ubi_dlRemove( ubi_dlListPtr ListPtr, ubi_dlNodePtr Old );
 163   /* ------------------------------------------------------------------------ **
 164    * Remove a node from the list.
 165    *
 166    *  Input:  ListPtr - A pointer to the list from which <Old> is to be
 167    *                    removed.
 168    *          Old     - A pointer to the node that is to be removed from the
 169    *                    list.
 170    *
 171    *  Output: A pointer to the node that was removed (i.e., <Old>).
 172    *
 173    * ------------------------------------------------------------------------ **
 174    */
 175
 176
 177 /* ================================ The End ================================= */
 178 #endif /* ubi_dLinkList_H */