1/* ========================================================================== ** 2 * ubi_dLinkList.c 3 * 4 * Copyright (C) 1997, 1998 by Christopher R. Hertel 5 * 6 * Email: crh@ubiqx.mn.org 7 * -------------------------------------------------------------------------- ** 8 * This module implements simple doubly-linked lists. 9 * -------------------------------------------------------------------------- ** 10 * 11 * This library is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU Library General Public 13 * License as published by the Free Software Foundation; either 14 * version 2 of the License, or (at your option) any later version. 15 * 16 * This library is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 19 * Library General Public License for more details. 20 * 21 * You should have received a copy of the GNU Library General Public 22 * License along with this library; if not, write to the Free 23 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 24 * 25 * -------------------------------------------------------------------------- ** 26 * 27 * Log: ubi_dLinkList.c,v 28 * Revision 0.11 1999/06/19 16:58:06 crh 29 * Renamed the ubi_slRemove() function in ubi_sLinkList to 30 * ubi_slRemoveNext(). I was bothered by the fact that it didn't 31 * match the functionality of the ubi_dlRemove() function in 32 * ubi_dLinkList. The new name is more 'correct'. 33 * 34 * Revision 0.10 1998/07/24 07:30:20 crh 35 * Added the ubi_dlNewList() macro. 36 * 37 * Revision 0.9 1998/06/04 21:29:27 crh 38 * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. 39 * This is more "standard", and is what people expect. Weird, eh? 40 * 41 * Revision 0.8 1998/06/03 18:06:03 crh 42 * Further fiddling with sys_include.h, which has been moved from the .c file 43 * to the .h file. 44 * 45 * Revision 0.7 1998/06/02 01:38:47 crh 46 * Changed include file name from ubi_null.h to sys_include.h to make it 47 * more generic. 48 * 49 * Revision 0.6 1998/05/20 04:38:05 crh 50 * The C file now includes ubi_null.h. See ubi_null.h for more info. 51 * 52 * Revision 0.5 1998/03/10 02:55:00 crh 53 * Simplified the code and added macros for stack & queue manipulations. 54 * 55 * Revision 0.4 1998/01/03 01:53:56 crh 56 * Added ubi_dlCount() macro. 57 * 58 * Revision 0.3 1997/10/15 03:05:39 crh 59 * Added some handy type casting to the macros. Added AddHere and RemThis 60 * macros. 61 * 62 * Revision 0.2 1997/10/08 03:07:21 crh 63 * Fixed a few forgotten link-ups in Insert(), and fixed the AddHead() 64 * macro, which was passing the wrong value for <After> to Insert(). 65 * 66 * Revision 0.1 1997/10/07 04:34:07 crh 67 * Initial Revision. 68 * 69 * -------------------------------------------------------------------------- ** 70 * This module is similar to the ubi_sLinkList module, but it is neither a 71 * descendant type nor an easy drop-in replacement for the latter. One key 72 * difference is that the ubi_dlRemove() function removes the indicated node, 73 * while the ubi_slRemoveNext() function (in ubi_sLinkList) removes the node 74 * *following* the indicated node. 75 * 76 * ========================================================================== ** 77 */ 78 79#include "ubi_dLinkList.h" /* Header for *this* module. */ 80 81/* ========================================================================== ** 82 * Functions... 83 */ 84 85ubi_dlListPtr ubi_dlInitList( ubi_dlListPtr ListPtr ) 86 /* ------------------------------------------------------------------------ ** 87 * Initialize a doubly-linked list header. 88 * 89 * Input: ListPtr - A pointer to the list structure that is to be 90 * initialized for use. 91 * 92 * Output: A pointer to the initialized list header (i.e., same as 93 * <ListPtr>). 94 * 95 * ------------------------------------------------------------------------ ** 96 */ 97 { 98 ListPtr->Head = NULL; 99 ListPtr->Tail = NULL; 100 ListPtr->count = 0; 101 return( ListPtr ); 102 } /* ubi_dlInitList */ 103 104ubi_dlNodePtr ubi_dlInsert( ubi_dlListPtr ListPtr, 105 ubi_dlNodePtr New, 106 ubi_dlNodePtr After ) 107 /* ------------------------------------------------------------------------ ** 108 * Insert a new node into the list. 109 * 110 * Input: ListPtr - A pointer to the list into which the node is to 111 * be inserted. 112 * New - Pointer to the new node. 113 * After - NULL, or a pointer to a node that is already in the 114 * list. 115 * If NULL, then <New> will be added at the head of the 116 * list, else it will be added following <After>. 117 * 118 * Output: A pointer to the node that was inserted into the list (i.e., 119 * the same as <New>). 120 * 121 * ------------------------------------------------------------------------ ** 122 */ 123 { 124 ubi_dlNodePtr PredNode = After ? After : (ubi_dlNodePtr)ListPtr; 125 126 New->Next = PredNode->Next; 127 New->Prev = After; 128 PredNode->Next = New; 129 if( New->Next ) 130 New->Next->Prev = New; 131 else 132 ListPtr->Tail = New; 133 134 (ListPtr->count)++; 135 136 return( New ); 137 } /* ubi_dlInsert */ 138 139ubi_dlNodePtr ubi_dlRemove( ubi_dlListPtr ListPtr, ubi_dlNodePtr Old ) 140 /* ------------------------------------------------------------------------ ** 141 * Remove a node from the list. 142 * 143 * Input: ListPtr - A pointer to the list from which <Old> is to be 144 * removed. 145 * Old - A pointer to the node that is to be removed from the 146 * list. 147 * 148 * Output: A pointer to the node that was removed (i.e., <Old>). 149 * 150 * ------------------------------------------------------------------------ ** 151 */ 152 { 153 if( Old ) 154 { 155 if( Old->Next ) 156 Old->Next->Prev = Old->Prev; 157 else 158 ListPtr->Tail = Old->Prev; 159 160 if( Old->Prev ) 161 Old->Prev->Next = Old->Next; 162 else 163 ListPtr->Head = Old->Next; 164 165 (ListPtr->count)--; 166 } 167 168 return( Old ); 169 } /* ubi_dlRemove */ 170 171/* ================================ The End ================================= */ 172