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 $	*/
 | |
| 
 | |
| /*
 | |
|  * Copyright (c) 1988, 1989, 1990, 1993
 | |
|  *	The Regents of the University of California.  All rights reserved.
 | |
|  *
 | |
|  * This code is derived from software contributed to Berkeley by
 | |
|  * Adam de Boor.
 | |
|  *
 | |
|  * Redistribution and use in source and binary forms, with or without
 | |
|  * modification, are permitted provided that the following conditions
 | |
|  * are met:
 | |
|  * 1. Redistributions of source code must retain the above copyright
 | |
|  *    notice, this list of conditions and the following disclaimer.
 | |
|  * 2. Redistributions in binary form must reproduce the above copyright
 | |
|  *    notice, this list of conditions and the following disclaimer in the
 | |
|  *    documentation and/or other materials provided with the distribution.
 | |
|  * 3. Neither the name of the University nor the names of its contributors
 | |
|  *    may be used to endorse or promote products derived from this software
 | |
|  *    without specific prior written permission.
 | |
|  *
 | |
|  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 | |
|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 | |
|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 | |
|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 | |
|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 | |
|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 | |
|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 | |
|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 | |
|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 | |
|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 | |
|  * SUCH DAMAGE.
 | |
|  */
 | |
| 
 | |
| #ifndef MAKE_NATIVE
 | |
| static char rcsid[] = "$NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $";
 | |
| #else
 | |
| #include <sys/cdefs.h>
 | |
| #ifndef lint
 | |
| #if 0
 | |
| static char sccsid[] = "@(#)lstInsert.c	8.1 (Berkeley) 6/6/93";
 | |
| #else
 | |
| __RCSID("$NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $");
 | |
| #endif
 | |
| #endif /* not lint */
 | |
| #endif
 | |
| 
 | |
| /*-
 | |
|  * LstInsert.c --
 | |
|  *	Insert a new datum before an old one
 | |
|  */
 | |
| 
 | |
| #include	"lstInt.h"
 | |
| 
 | |
| /*-
 | |
|  *-----------------------------------------------------------------------
 | |
|  * Lst_InsertBefore --
 | |
|  *	Insert a new node with the given piece of data before the given
 | |
|  *	node in the given list.
 | |
|  *
 | |
|  * Input:
 | |
|  *	l		list to manipulate
 | |
|  *	ln		node before which to insert d
 | |
|  *	d		datum to be inserted
 | |
|  *
 | |
|  * Results:
 | |
|  *	SUCCESS or FAILURE.
 | |
|  *
 | |
|  * Side Effects:
 | |
|  *	the firstPtr field will be changed if ln is the first node in the
 | |
|  *	list.
 | |
|  *
 | |
|  *-----------------------------------------------------------------------
 | |
|  */
 | |
| ReturnStatus
 | |
| Lst_InsertBefore(Lst l, LstNode ln, void *d)
 | |
| {
 | |
|     ListNode	nLNode;	/* new lnode for d */
 | |
|     ListNode	lNode = ln;
 | |
|     List 	list = l;
 | |
| 
 | |
| 
 | |
|     /*
 | |
|      * check validity of arguments
 | |
|      */
 | |
|     if (LstValid (l) && (LstIsEmpty (l) && ln == NULL))
 | |
| 	goto ok;
 | |
| 
 | |
|     if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) {
 | |
| 	return (FAILURE);
 | |
|     }
 | |
| 
 | |
|     ok:
 | |
|     PAlloc (nLNode, ListNode);
 | |
| 
 | |
|     nLNode->datum = d;
 | |
|     nLNode->useCount = nLNode->flags = 0;
 | |
| 
 | |
|     if (ln == NULL) {
 | |
| 	if (list->isCirc) {
 | |
| 	    nLNode->prevPtr = nLNode->nextPtr = nLNode;
 | |
| 	} else {
 | |
| 	    nLNode->prevPtr = nLNode->nextPtr = NULL;
 | |
| 	}
 | |
| 	list->firstPtr = list->lastPtr = nLNode;
 | |
|     } else {
 | |
| 	nLNode->prevPtr = lNode->prevPtr;
 | |
| 	nLNode->nextPtr = lNode;
 | |
| 
 | |
| 	if (nLNode->prevPtr != NULL) {
 | |
| 	    nLNode->prevPtr->nextPtr = nLNode;
 | |
| 	}
 | |
| 	lNode->prevPtr = nLNode;
 | |
| 
 | |
| 	if (lNode == list->firstPtr) {
 | |
| 	    list->firstPtr = nLNode;
 | |
| 	}
 | |
|     }
 | |
| 
 | |
|     return (SUCCESS);
 | |
| }
 | |
| 
 | 
