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Diffstat (limited to 'lst.lib/lstInsert.c')
| -rw-r--r-- | lst.lib/lstInsert.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/lst.lib/lstInsert.c b/lst.lib/lstInsert.c new file mode 100644 index 0000000..77187bb --- /dev/null +++ b/lst.lib/lstInsert.c @@ -0,0 +1,122 @@ +/* $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); +} + |