xref: /netbsd-src/lib/libc/citrus/citrus_db_hash.c (revision f59892f81b2a9f6b8bcc73005fe92eaf318e5d70)
1 /*	$NetBSD: citrus_db_hash.c,v 1.5 2008/02/09 14:56:20 junyoung Exp $	*/
2 
3 /*-
4  * Copyright (c)2003 Citrus Project,
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #if HAVE_NBTOOL_CONFIG_H
30 #include "nbtool_config.h"
31 #endif
32 
33 #include <sys/cdefs.h>
34 #if defined(LIBC_SCCS) && !defined(lint)
35 __RCSID("$NetBSD: citrus_db_hash.c,v 1.5 2008/02/09 14:56:20 junyoung Exp $");
36 #endif /* LIBC_SCCS and not lint */
37 
38 #ifndef HOSTPROG
39 #include "namespace.h"
40 #endif
41 #include <assert.h>
42 #include <stdio.h>
43 #include <string.h>
44 #include <sys/types.h>
45 
46 #include "citrus_namespace.h"
47 #include "citrus_types.h"
48 #include "citrus_bcs.h"
49 #include "citrus_region.h"
50 #include "citrus_db_hash.h"
51 
52 uint32_t
53 /*ARGSUSED*/
_citrus_db_hash_std(void * closure,struct _region * r)54 _citrus_db_hash_std(void *closure, struct _region *r)
55 {
56 	const uint8_t *p = _region_head(r);
57 	uint32_t hash = 0, tmp;
58 	size_t i;
59 
60 	for (i = _region_size(r); i > 0; i--) {
61 		hash <<= 4;
62 		hash += _bcs_tolower(*p);
63 		tmp = hash & 0xF0000000;
64 		if (tmp != 0) {
65 			hash ^= tmp;
66 			hash ^= tmp >> 24;
67 		}
68 		p++;
69 	}
70 	return hash;
71 }
72