source/ubiqx/ubi_dLinkList.h

   1 #ifndef UBI_DLINKLIST_H
   2 #define UBI_DLINKLIST_H
   3 /* ========================================================================== **
   4  *                              ubi_dLinkList.h
   5  *
   6  *  Copyright (C) 1997, 1998 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  * Log: ubi_dLinkList.h,v
  30  * Revision 0.11  1999/06/19 16:58:06  crh
  31  * Renamed the ubi_slRemove() function in ubi_sLinkList to
  32  * ubi_slRemoveNext().  I was bothered by the fact that it didn't
  33  * match the functionality of the ubi_dlRemove() function in
  34  * ubi_dLinkList.  The new name is more 'correct'.
  35  *
  36  * Revision 0.10  1998/07/24 07:30:20  crh
  37  * Added the ubi_dlNewList() macro.
  38  *
  39  * Revision 0.9  1998/06/04 21:29:27  crh
  40  * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files.
  41  * This is more "standard", and is what people expect.  Weird, eh?
  42  *
  43  * Revision 0.8  1998/06/03 18:06:03  crh
  44  * Further fiddling with sys_include.h, which has been moved from the .c file
  45  * to the .h file.
  46  *
  47  * Revision 0.7  1998/06/02 01:38:47  crh
  48  * Changed include file name from ubi_null.h to sys_include.h to make it
  49  * more generic.
  50  *
  51  * Revision 0.6  1998/05/20 04:38:05  crh
  52  * The C file now includes ubi_null.h.  See ubi_null.h for more info.
  53  *
  54  * Revision 0.5  1998/03/10 02:54:04  crh
  55  * Simplified the code and added macros for stack & queue manipulations.
  56  *
  57  * Revision 0.4  1998/01/03 01:53:44  crh
  58  * Added ubi_dlCount() macro.
  59  *
  60  * Revision 0.3  1997/10/15 03:04:31  crh
  61  * Added some handy type casting to the macros.  Added AddHere and RemThis
  62  * macros.
  63  *
  64  * Revision 0.2  1997/10/08 03:08:16  crh
  65  * Fixed a few forgotten link-ups in Insert(), and fixed the AddHead()
  66  * macro, which was passing the wrong value for <After> to Insert().
  67  *
  68  * Revision 0.1  1997/10/07 04:34:38  crh
  69  * Initial Revision.
  70  *
  71  * -------------------------------------------------------------------------- **
  72  * This module is similar to the ubi_sLinkList module, but it is neither a
  73  * descendant type nor an easy drop-in replacement for the latter.  One key
  74  * difference is that the ubi_dlRemove() function removes the indicated node,
  75  * while the ubi_slRemoveNext() function (in ubi_sLinkList) removes the node
  76  * *following* the indicated node.
  77  *
  78  * ========================================================================== **
  79  */
  80
  81 #include "sys_include.h"    /* System-specific includes. */
  82
  83 /* ========================================================================== **
  84  * Typedefs...
  85  *
  86  *  ubi_dlNode    - This is the basic node structure.
  87  *  ubi_dlNodePtr - Pointer to a node.
  88  *  ubi_dlList    - This is the list header structure.
  89  *  ubi_dlListPtr - Pointer to a List (i.e., a list header structure).
  90  *
  91  */
  92
  93 typedef struct ubi_dlListNode
  94   {
  95   struct ubi_dlListNode *Next;
  96   struct ubi_dlListNode *Prev;
  97   } ubi_dlNode;
  98
  99 typedef ubi_dlNode *ubi_dlNodePtr;
 100
 101 typedef struct
 102   {
 103   ubi_dlNodePtr Head;
 104   ubi_dlNodePtr Tail;
 105   unsigned long count;
 106   } ubi_dlList;
 107
 108 typedef ubi_dlList *ubi_dlListPtr;
 109
 110 /* ========================================================================== **
 111  * Macros...
 112  *
 113  *  ubi_dlNewList - Macro used to declare and initialize a new list in one
 114  *                  swell foop.  It is used when defining a variable of
 115  *                  type ubi_dlList.  The definition
 116  *                    static ubi_dlNewList( gerbil );
 117  *                  is translated to
 118  *                    static ubi_dlList gerbil[1] = {{ NULL, NULL, 0 }};
 119  *
 120  *  ubi_dlCount   - Return the number of entries currently in the list.
 121  *
 122  *  ubi_dlAddHead - Add a new node at the head of the list.
 123  *  ubi_dlAddNext - Add a node following the given node.
 124  *  ubi_dlAddTail - Add a new node at the tail of the list.
 125  *                  Note: AddTail evaluates the L parameter twice.
 126  *
 127  *  ubi_dlRemHead - Remove the node at the head of the list, if any.
 128  *                  Note: RemHead evaluates the L parameter twice.
 129  *  ubi_dlRemThis - Remove the indicated node.
 130  *  ubi_dlRemTail - Remove the node at the tail of the list, if any.
 131  *                  Note: RemTail evaluates the L parameter twice.
 132  *
 133  *  ubi_dlFirst   - Return a pointer to the first node in the list, if any.
 134  *  ubi_dlLast    - Return a pointer to the last node in the list, if any.
 135  *  ubi_dlNext    - Given a node, return a pointer to the next node.
 136  *  ubi_dlPrev    - Given a node, return a pointer to the previous node.
 137  *
 138  *  ubi_dlPush    - Add a node at the head of the list (synonym of AddHead).
 139  *  ubi_dlPop     - Remove a node at the head of the list (synonym of RemHead).
 140  *  ubi_dlEnqueue - Add a node at the tail of the list (sysnonym of AddTail).
 141  *  ubi_dlDequeue - Remove a node at the head of the list (synonym of RemHead).
 142  *
 143  *  Note that all of these provide type casting of the parameters.  The
 144  *  Add and Rem macros are nothing more than nice front-ends to the
 145  *  Insert and Remove operations.
 146  *
 147  *  Also note that the First, Next and Last macros do no parameter checking!
 148  *
 149  */
 150
 151 #define ubi_dlNewList( L ) ubi_dlList (L)[1] = {{ NULL, NULL, 0 }}
 152
 153 #define ubi_dlCount( L ) (((ubi_dlListPtr)(L))->count)
 154
 155 #define ubi_dlAddHead( L, N ) \
 156         ubi_dlInsert( (ubi_dlListPtr)(L), (ubi_dlNodePtr)(N), NULL )
 157
 158 #define ubi_dlAddNext( L, N, A ) \
 159         ubi_dlInsert( (ubi_dlListPtr)(L), \
 160                       (ubi_dlNodePtr)(N), \
 161                       (ubi_dlNodePtr)(A) )
 162
 163 #define ubi_dlAddTail( L, N ) \
 164         ubi_dlInsert( (ubi_dlListPtr)(L), \
 165                       (ubi_dlNodePtr)(N), \
 166                     (((ubi_dlListPtr)(L))->Tail) )
 167
 168 #define ubi_dlRemHead( L ) ubi_dlRemove( (ubi_dlListPtr)(L), \
 169                                          (((ubi_dlListPtr)(L))->Head) )
 170
 171 #define ubi_dlRemThis( L, N ) ubi_dlRemove( (ubi_dlListPtr)(L), \
 172                                             (ubi_dlNodePtr)(N) )
 173
 174 #define ubi_dlRemTail( L ) ubi_dlRemove( (ubi_dlListPtr)(L), \
 175                                          (((ubi_dlListPtr)(L))->Tail) )
 176
 177 #define ubi_dlFirst( L ) (((ubi_dlListPtr)(L))->Head)
 178
 179 #define ubi_dlLast( L )  (((ubi_dlListPtr)(L))->Tail)
 180
 181 #define ubi_dlNext( N )  (((ubi_dlNodePtr)(N))->Next)
 182
 183 #define ubi_dlPrev( N )  (((ubi_dlNodePtr)(N))->Prev)
 184
 185 #define ubi_dlPush    ubi_dlAddHead
 186 #define ubi_dlPop     ubi_dlRemHead
 187 #define ubi_dlEnqueue ubi_dlAddTail
 188 #define ubi_dlDequeue ubi_dlRemHead
 189
 190 /* ========================================================================== **
 191  * Function prototypes...
 192  */
 193
 194 ubi_dlListPtr ubi_dlInitList( ubi_dlListPtr ListPtr );
 195   /* ------------------------------------------------------------------------ **
 196    * Initialize a doubly-linked list header.
 197    *
 198    *  Input:  ListPtr - A pointer to the list structure that is to be
 199    *                    initialized for use.
 200    *
 201    *  Output: A pointer to the initialized list header (i.e., same as
 202    *          <ListPtr>).
 203    *
 204    * ------------------------------------------------------------------------ **
 205    */
 206
 207 ubi_dlNodePtr ubi_dlInsert( ubi_dlListPtr ListPtr,
 208                             ubi_dlNodePtr New,
 209                             ubi_dlNodePtr After );
 210   /* ------------------------------------------------------------------------ **
 211    * Insert a new node into the list.
 212    *
 213    *  Input:  ListPtr - A pointer to the list into which the node is to
 214    *                    be inserted.
 215    *          New     - Pointer to the new node.
 216    *          After   - NULL, or a pointer to a node that is already in the
 217    *                    list.
 218    *                    If NULL, then <New> will be added at the head of the
 219    *                    list, else it will be added following <After>.
 220    *
 221    *  Output: A pointer to the node that was inserted into the list (i.e.,
 222    *          the same as <New>).
 223    *
 224    * ------------------------------------------------------------------------ **
 225    */
 226
 227 ubi_dlNodePtr ubi_dlRemove( ubi_dlListPtr ListPtr, ubi_dlNodePtr Old );
 228   /* ------------------------------------------------------------------------ **
 229    * Remove a node from the list.
 230    *
 231    *  Input:  ListPtr - A pointer to the list from which <Old> is to be
 232    *                    removed.
 233    *          Old     - A pointer to the node that is to be removed from the
 234    *                    list.
 235    *
 236    *  Output: A pointer to the node that was removed (i.e., <Old>).
 237    *
 238    * ------------------------------------------------------------------------ **
 239    */
 240
 241 /* ================================ The End ================================= */
 242 #endif /* UBI_DLINKLIST_H */