1 /* $OpenBSD: uuid_hash.c,v 1.2 2015/09/10 18:13:46 guenther Exp $ */
2 /* $NetBSD: uuid_hash.c,v 1.2 2008/04/23 07:52:32 plunky Exp $ */
3
4 /*
5 * Copyright (c) 2002 Marcel Moolenaar
6 * Copyright (c) 2002 Hiten Mahesh Pandya
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $FreeBSD: src/lib/libc/uuid/uuid_hash.c,v 1.2 2003/08/08 19:18:43 marcel Exp $
31 */
32
33 #include <uuid.h>
34
35 /*
36 * uuid_hash() - generate a hash value.
37 * See also:
38 * http://www.opengroup.org/onlinepubs/009629399/uuid_hash.htm
39 */
40 uint16_t
uuid_hash(const uuid_t * u,uint32_t * status)41 uuid_hash(const uuid_t *u, uint32_t *status)
42 {
43 if (status)
44 *status = uuid_s_ok;
45
46 /*
47 * Use the most frequently changing bits in the UUID as the hash
48 * value. This should yield a good enough distribution...
49 */
50 return ((u) ? u->time_low & 0xffff : 0);
51 }
52