lstInsert.c revision 236769
1/* $NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $ */ 2 3/* 4 * Copyright (c) 1988, 1989, 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Adam de Boor. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#ifndef MAKE_NATIVE 36static char rcsid[] = "$NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $"; 37#else 38#include <sys/cdefs.h> 39#ifndef lint 40#if 0 41static char sccsid[] = "@(#)lstInsert.c 8.1 (Berkeley) 6/6/93"; 42#else 43__RCSID("$NetBSD: lstInsert.c,v 1.14 2009/01/23 21:26:30 dsl Exp $"); 44#endif 45#endif /* not lint */ 46#endif 47 48/*- 49 * LstInsert.c -- 50 * Insert a new datum before an old one 51 */ 52 53#include "lstInt.h" 54 55/*- 56 *----------------------------------------------------------------------- 57 * Lst_InsertBefore -- 58 * Insert a new node with the given piece of data before the given 59 * node in the given list. 60 * 61 * Input: 62 * l list to manipulate 63 * ln node before which to insert d 64 * d datum to be inserted 65 * 66 * Results: 67 * SUCCESS or FAILURE. 68 * 69 * Side Effects: 70 * the firstPtr field will be changed if ln is the first node in the 71 * list. 72 * 73 *----------------------------------------------------------------------- 74 */ 75ReturnStatus 76Lst_InsertBefore(Lst l, LstNode ln, void *d) 77{ 78 ListNode nLNode; /* new lnode for d */ 79 ListNode lNode = ln; 80 List list = l; 81 82 83 /* 84 * check validity of arguments 85 */ 86 if (LstValid (l) && (LstIsEmpty (l) && ln == NULL)) 87 goto ok; 88 89 if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) { 90 return (FAILURE); 91 } 92 93 ok: 94 PAlloc (nLNode, ListNode); 95 96 nLNode->datum = d; 97 nLNode->useCount = nLNode->flags = 0; 98 99 if (ln == NULL) { 100 if (list->isCirc) { 101 nLNode->prevPtr = nLNode->nextPtr = nLNode; 102 } else { 103 nLNode->prevPtr = nLNode->nextPtr = NULL; 104 } 105 list->firstPtr = list->lastPtr = nLNode; 106 } else { 107 nLNode->prevPtr = lNode->prevPtr; 108 nLNode->nextPtr = lNode; 109 110 if (nLNode->prevPtr != NULL) { 111 nLNode->prevPtr->nextPtr = nLNode; 112 } 113 lNode->prevPtr = nLNode; 114 115 if (lNode == list->firstPtr) { 116 list->firstPtr = nLNode; 117 } 118 } 119 120 return (SUCCESS); 121} 122 123