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
36 static char rcsid[] = "$NetBSD: lstForEachFrom.c,v 1.17 2009/01/23 21:26:30 dsl Exp $";
37 #else
38 #include <sys/cdefs.h>
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)lstForEachFrom.c 8.1 (Berkeley) 6/6/93";
42 #else
43 __RCSID("$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*/
72 int
Lst_ForEachFrom(Lst l,LstNode ln,int (* proc)(void *,void *),void * d)73 Lst_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