123 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			123 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*	$NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $	*/
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/*
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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. 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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#ifndef MAKE_NATIVE
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static char rcsid[] = "$NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $";
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#else
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#include <sys/cdefs.h>
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#ifndef lint
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#if 0
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static char sccsid[] = "@(#)lstInsert.c	8.1 (Berkeley) 6/6/93";
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#else
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__RCSID("$NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $");
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#endif
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#endif /* not lint */
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#endif
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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_InsertBefore --
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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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 * Input:
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 *	l		list to manipulate
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 *	ln		node before which to insert d
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 *	d		datum to be inserted
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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_InsertBefore(Lst l, LstNode ln, void *d)
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{
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    ListNode	nLNode;	/* new lnode for d */
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    ListNode	lNode = ln;
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    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 == NULL))
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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 == NULL) {
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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 = NULL;
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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 != NULL) {
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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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