1 /* $NetBSD: uuid_hash.c,v 1.2 2008/04/23 07:52:32 plunky Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 Marcel Moolenaar 5 * Copyright (c) 2002 Hiten Mahesh Pandya 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD: src/lib/libc/uuid/uuid_hash.c,v 1.2 2003/08/08 19:18:43 marcel Exp $ 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 __RCSID("$NetBSD: uuid_hash.c,v 1.2 2008/04/23 07:52:32 plunky Exp $"); 35 #endif 36 37 #include "namespace.h" 38 39 #include <uuid.h> 40 41 /* 42 * uuid_hash() - generate a hash value. 43 * See also: 44 * http://www.opengroup.org/onlinepubs/009629399/uuid_hash.htm 45 */ 46 uint16_t 47 uuid_hash(const uuid_t *u, uint32_t *status) 48 { 49 50 if (status) 51 *status = uuid_s_ok; 52 53 /* 54 * Use the most frequently changing bits in the UUID as the hash 55 * value. This should yield a good enough distribution... 56 */ 57 return ((u) ? u->time_low & 0xffff : 0); 58 } 59