xref: /minix3/lib/libintl/strhash.c (revision 36dcc4a4a93f782ada76dce3d52fbeab0e063cf1)
1*36dcc4a4SLionel Sambuc /*	$NetBSD: strhash.c,v 1.3 2007/09/25 08:19:09 junyoung Exp $	*/
2*36dcc4a4SLionel Sambuc 
3*36dcc4a4SLionel Sambuc /*-
4*36dcc4a4SLionel Sambuc  * Copyright (c)2003, 2004 Citrus Project,
5*36dcc4a4SLionel Sambuc  * All rights reserved.
6*36dcc4a4SLionel Sambuc  *
7*36dcc4a4SLionel Sambuc  * Redistribution and use in source and binary forms, with or without
8*36dcc4a4SLionel Sambuc  * modification, are permitted provided that the following conditions
9*36dcc4a4SLionel Sambuc  * are met:
10*36dcc4a4SLionel Sambuc  * 1. Redistributions of source code must retain the above copyright
11*36dcc4a4SLionel Sambuc  *    notice, this list of conditions and the following disclaimer.
12*36dcc4a4SLionel Sambuc  * 2. Redistributions in binary form must reproduce the above copyright
13*36dcc4a4SLionel Sambuc  *    notice, this list of conditions and the following disclaimer in the
14*36dcc4a4SLionel Sambuc  *    documentation and/or other materials provided with the distribution.
15*36dcc4a4SLionel Sambuc  *
16*36dcc4a4SLionel Sambuc  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17*36dcc4a4SLionel Sambuc  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18*36dcc4a4SLionel Sambuc  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19*36dcc4a4SLionel Sambuc  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20*36dcc4a4SLionel Sambuc  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21*36dcc4a4SLionel Sambuc  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22*36dcc4a4SLionel Sambuc  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23*36dcc4a4SLionel Sambuc  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24*36dcc4a4SLionel Sambuc  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25*36dcc4a4SLionel Sambuc  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26*36dcc4a4SLionel Sambuc  * SUCH DAMAGE.
27*36dcc4a4SLionel Sambuc  */
28*36dcc4a4SLionel Sambuc 
29*36dcc4a4SLionel Sambuc #include <sys/cdefs.h>
30*36dcc4a4SLionel Sambuc #if defined(LIBC_SCCS) && !defined(lint)
31*36dcc4a4SLionel Sambuc __RCSID("$NetBSD: strhash.c,v 1.3 2007/09/25 08:19:09 junyoung Exp $");
32*36dcc4a4SLionel Sambuc #endif /* LIBC_SCCS and not lint */
33*36dcc4a4SLionel Sambuc 
34*36dcc4a4SLionel Sambuc #include <sys/param.h>
35*36dcc4a4SLionel Sambuc #include <sys/types.h>
36*36dcc4a4SLionel Sambuc 
37*36dcc4a4SLionel Sambuc #include "libintl_local.h"
38*36dcc4a4SLionel Sambuc 
39*36dcc4a4SLionel Sambuc /*
40*36dcc4a4SLionel Sambuc  * string hash function by P.J.Weinberger.
41*36dcc4a4SLionel Sambuc  * this implementation is derived from src/lib/libc/citrus/citrus_db_hash.c.
42*36dcc4a4SLionel Sambuc  */
43*36dcc4a4SLionel Sambuc uint32_t
44*36dcc4a4SLionel Sambuc /*ARGSUSED*/
__intl_string_hash(const char * str)45*36dcc4a4SLionel Sambuc __intl_string_hash(const char *str)
46*36dcc4a4SLionel Sambuc {
47*36dcc4a4SLionel Sambuc 	const uint8_t *p;
48*36dcc4a4SLionel Sambuc 	uint32_t hash = 0, tmp;
49*36dcc4a4SLionel Sambuc 
50*36dcc4a4SLionel Sambuc 	for (p = (const uint8_t *)str; *p; p++) {
51*36dcc4a4SLionel Sambuc 		hash <<= 4;
52*36dcc4a4SLionel Sambuc 		hash += *p;
53*36dcc4a4SLionel Sambuc 		tmp = hash & 0xF0000000;
54*36dcc4a4SLionel Sambuc 		if (tmp != 0) {
55*36dcc4a4SLionel Sambuc 			hash ^= tmp;
56*36dcc4a4SLionel Sambuc 			hash ^= tmp >> 24;
57*36dcc4a4SLionel Sambuc 		}
58*36dcc4a4SLionel Sambuc 	}
59*36dcc4a4SLionel Sambuc 	return hash;
60*36dcc4a4SLionel Sambuc }
61