116 lines
3.6 KiB
C
116 lines
3.6 KiB
C
/*
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* Copyright (c) 1988, 1989, 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Adam de Boor.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $Id$
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*/
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#ifndef lint
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static char sccsid[] = "@(#)lstInsert.c 8.1 (Berkeley) 6/6/93";
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#endif /* not lint */
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/*-
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* LstInsert.c --
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* Insert a new datum before an old one
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*/
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#include "lstInt.h"
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/*-
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*-----------------------------------------------------------------------
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* Lst_Insert --
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* Insert a new node with the given piece of data before the given
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* node in the given list.
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*
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* Results:
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* SUCCESS or FAILURE.
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*
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* Side Effects:
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* the firstPtr field will be changed if ln is the first node in the
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* list.
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*
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*-----------------------------------------------------------------------
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*/
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ReturnStatus
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Lst_Insert (l, ln, d)
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Lst l; /* list to manipulate */
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LstNode ln; /* node before which to insert d */
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ClientData d; /* datum to be inserted */
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{
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register ListNode nLNode; /* new lnode for d */
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register ListNode lNode = (ListNode)ln;
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register List list = (List)l;
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/*
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* check validity of arguments
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*/
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if (LstValid (l) && (LstIsEmpty (l) && ln == NILLNODE))
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goto ok;
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if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) {
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return (FAILURE);
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}
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ok:
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PAlloc (nLNode, ListNode);
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nLNode->datum = d;
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nLNode->useCount = nLNode->flags = 0;
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if (ln == NILLNODE) {
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if (list->isCirc) {
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nLNode->prevPtr = nLNode->nextPtr = nLNode;
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} else {
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nLNode->prevPtr = nLNode->nextPtr = NilListNode;
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}
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list->firstPtr = list->lastPtr = nLNode;
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} else {
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nLNode->prevPtr = lNode->prevPtr;
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nLNode->nextPtr = lNode;
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if (nLNode->prevPtr != NilListNode) {
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nLNode->prevPtr->nextPtr = nLNode;
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}
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lNode->prevPtr = nLNode;
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if (lNode == list->firstPtr) {
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list->firstPtr = nLNode;
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}
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}
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return (SUCCESS);
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}
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