/* ========================================================================== ** * ubi_dLinkList.c * * Copyright (C) 1997, 1998 by Christopher R. Hertel * * Email: crh@ubiqx.mn.org * -------------------------------------------------------------------------- ** * This module implements simple doubly-linked lists. * -------------------------------------------------------------------------- ** * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * -------------------------------------------------------------------------- ** * * Log: ubi_dLinkList.c,v * Revision 0.11 1999/06/19 16:58:06 crh * Renamed the ubi_slRemove() function in ubi_sLinkList to * ubi_slRemoveNext(). I was bothered by the fact that it didn't * match the functionality of the ubi_dlRemove() function in * ubi_dLinkList. The new name is more 'correct'. * * Revision 0.10 1998/07/24 07:30:20 crh * Added the ubi_dlNewList() macro. * * Revision 0.9 1998/06/04 21:29:27 crh * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. * This is more "standard", and is what people expect. Weird, eh? * * Revision 0.8 1998/06/03 18:06:03 crh * Further fiddling with sys_include.h, which has been moved from the .c file * to the .h file. * * Revision 0.7 1998/06/02 01:38:47 crh * Changed include file name from ubi_null.h to sys_include.h to make it * more generic. * * Revision 0.6 1998/05/20 04:38:05 crh * The C file now includes ubi_null.h. See ubi_null.h for more info. * * Revision 0.5 1998/03/10 02:55:00 crh * Simplified the code and added macros for stack & queue manipulations. * * Revision 0.4 1998/01/03 01:53:56 crh * Added ubi_dlCount() macro. * * Revision 0.3 1997/10/15 03:05:39 crh * Added some handy type casting to the macros. Added AddHere and RemThis * macros. * * Revision 0.2 1997/10/08 03:07:21 crh * Fixed a few forgotten link-ups in Insert(), and fixed the AddHead() * macro, which was passing the wrong value for <After> to Insert(). * * Revision 0.1 1997/10/07 04:34:07 crh * Initial Revision. * * -------------------------------------------------------------------------- ** * This module is similar to the ubi_sLinkList module, but it is neither a * descendant type nor an easy drop-in replacement for the latter. One key * difference is that the ubi_dlRemove() function removes the indicated node, * while the ubi_slRemoveNext() function (in ubi_sLinkList) removes the node * *following* the indicated node. * * ========================================================================== ** */ #include "ubi_dLinkList.h" /* Header for *this* module. */ /* ========================================================================== ** * Functions... */ ubi_dlListPtr ubi_dlInitList( ubi_dlListPtr ListPtr ) /* ------------------------------------------------------------------------ ** * Initialize a doubly-linked list header. * * Input: ListPtr - A pointer to the list structure that is to be * initialized for use. * * Output: A pointer to the initialized list header (i.e., same as * <ListPtr>). * * ------------------------------------------------------------------------ ** */ { ListPtr->Head = NULL; ListPtr->Tail = NULL; ListPtr->count = 0; return( ListPtr ); } /* ubi_dlInitList */ ubi_dlNodePtr ubi_dlInsert( ubi_dlListPtr ListPtr, ubi_dlNodePtr New, ubi_dlNodePtr After ) /* ------------------------------------------------------------------------ ** * Insert a new node into the list. * * Input: ListPtr - A pointer to the list into which the node is to * be inserted. * New - Pointer to the new node. * After - NULL, or a pointer to a node that is already in the * list. * If NULL, then <New> will be added at the head of the * list, else it will be added following <After>. * * Output: A pointer to the node that was inserted into the list (i.e., * the same as <New>). * * ------------------------------------------------------------------------ ** */ { ubi_dlNodePtr PredNode = After ? After : (ubi_dlNodePtr)ListPtr; New->Next = PredNode->Next; New->Prev = After; PredNode->Next = New; if( New->Next ) New->Next->Prev = New; else ListPtr->Tail = New; (ListPtr->count)++; return( New ); } /* ubi_dlInsert */ ubi_dlNodePtr ubi_dlRemove( ubi_dlListPtr ListPtr, ubi_dlNodePtr Old ) /* ------------------------------------------------------------------------ ** * Remove a node from the list. * * Input: ListPtr - A pointer to the list from which <Old> is to be * removed. * Old - A pointer to the node that is to be removed from the * list. * * Output: A pointer to the node that was removed (i.e., <Old>). * * ------------------------------------------------------------------------ ** */ { if( Old ) { if( Old->Next ) Old->Next->Prev = Old->Prev; else ListPtr->Tail = Old->Prev; if( Old->Prev ) Old->Prev->Next = Old->Next; else ListPtr->Head = Old->Next; (ListPtr->count)--; } return( Old ); } /* ubi_dlRemove */ /* ================================ The End ================================= */