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Diffstat (limited to 'source/ubiqx/ubi_dLinkList.c')
| -rw-r--r-- | source/ubiqx/ubi_dLinkList.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/source/ubiqx/ubi_dLinkList.c b/source/ubiqx/ubi_dLinkList.c new file mode 100644 index 00000000000..eb95033c695 --- /dev/null +++ b/source/ubiqx/ubi_dLinkList.c @@ -0,0 +1,171 @@ +/* ========================================================================== ** + * 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 ================================= */ |