1/*	$NetBSD: lstForEachFrom.c,v 1.17 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: lstForEachFrom.c,v 1.17 2009/01/23 21:26:30 dsl Exp $";
37#else
38#include <sys/cdefs.h>
39#ifndef lint
40#if 0
41static char sccsid[] = "@(#)lstForEachFrom.c	8.1 (Berkeley) 6/6/93";
42#else
43__RCSID("$NetBSD: lstForEachFrom.c,v 1.17 2009/01/23 21:26:30 dsl Exp $");
44#endif
45#endif /* not lint */
46#endif
47
48/*-
49 * lstForEachFrom.c --
50 *	Perform a given function on all elements of a list starting from
51 *	a given point.
52 */
53
54#include	"lstInt.h"
55
56/*-
57 *-----------------------------------------------------------------------
58 * Lst_ForEachFrom --
59 *	Apply the given function to each element of the given list. The
60 *	function should return 0 if traversal should continue and non-
61 *	zero if it should abort.
62 *
63 * Results:
64 *	None.
65 *
66 * Side Effects:
67 *	Only those created by the passed-in function.
68 *
69 *-----------------------------------------------------------------------
70 */
71/*VARARGS2*/
72int
73Lst_ForEachFrom(Lst l, LstNode ln, int (*proc)(void *, void *),
74		void *d)
75{
76    ListNode	tln = ln;
77    List 	list = l;
78    ListNode	next;
79    Boolean 	    	done;
80    int     	    	result;
81
82    if (!LstValid (list) || LstIsEmpty (list)) {
83	return 0;
84    }
85
86    do {
87	/*
88	 * Take care of having the current element deleted out from under
89	 * us.
90	 */
91
92	next = tln->nextPtr;
93
94	/*
95	 * We're done with the traversal if
96	 *  - the next node to examine is the first in the queue or
97	 *    doesn't exist and
98	 *  - nothing's been added after the current node (check this
99	 *    after proc() has been called).
100	 */
101	done = (next == NULL || next == list->firstPtr);
102
103	(void) tln->useCount++;
104	result = (*proc) (tln->datum, d);
105	(void) tln->useCount--;
106
107	/*
108	 * Now check whether a node has been added.
109	 * Note: this doesn't work if this node was deleted before
110	 *       the new node was added.
111	 */
112	if (next != tln->nextPtr) {
113		next = tln->nextPtr;
114		done = 0;
115	}
116
117	if (tln->flags & LN_DELETED) {
118	    free((char *)tln);
119	}
120	tln = next;
121    } while (!result && !LstIsEmpty(list) && !done);
122
123    return result;
124}
125
126