1 /* $OpenBSD: lstInsert.c,v 1.4 1998/12/05 00:06:32 espie Exp $ */ 2 /* $NetBSD: lstInsert.c,v 1.5 1996/11/06 17:59:44 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1988, 1989, 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Adam de Boor. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)lstInsert.c 8.1 (Berkeley) 6/6/93"; 43 #else 44 static char rcsid[] = "$OpenBSD: lstInsert.c,v 1.4 1998/12/05 00:06:32 espie Exp $"; 45 #endif 46 #endif /* not lint */ 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_Insert -- 58 * Insert a new node with the given piece of data before the given 59 * node in the given list. 60 * 61 * Results: 62 * SUCCESS or FAILURE. 63 * 64 * Side Effects: 65 * the firstPtr field will be changed if ln is the first node in the 66 * list. 67 * 68 *----------------------------------------------------------------------- 69 */ 70 ReturnStatus 71 Lst_Insert (l, ln, d) 72 Lst l; /* list to manipulate */ 73 LstNode ln; /* node before which to insert d */ 74 ClientData d; /* datum to be inserted */ 75 { 76 register ListNode nLNode; /* new lnode for d */ 77 register ListNode lNode = (ListNode)ln; 78 register List list = (List)l; 79 80 81 /* 82 * check validity of arguments 83 */ 84 if (LstValid (l) && (LstIsEmpty (l) && ln == NILLNODE)) 85 goto ok; 86 87 if (!LstValid (l) || LstIsEmpty (l) || !LstNodeValid (ln, l)) { 88 return (FAILURE); 89 } 90 91 ok: 92 PAlloc (nLNode, ListNode); 93 94 nLNode->datum = d; 95 nLNode->useCount = nLNode->flags = 0; 96 97 if (ln == NILLNODE) { 98 if (list->isCirc) { 99 nLNode->prevPtr = nLNode->nextPtr = nLNode; 100 } else { 101 nLNode->prevPtr = nLNode->nextPtr = NilListNode; 102 } 103 list->firstPtr = list->lastPtr = nLNode; 104 } else { 105 nLNode->prevPtr = lNode->prevPtr; 106 nLNode->nextPtr = lNode; 107 108 if (nLNode->prevPtr != NilListNode) { 109 nLNode->prevPtr->nextPtr = nLNode; 110 } 111 lNode->prevPtr = nLNode; 112 113 if (lNode == list->firstPtr) { 114 list->firstPtr = nLNode; 115 } 116 } 117 118 return (SUCCESS); 119 } 120 121