uuid_hash.c revision 106184
1106184Smarcel/*- 2106184Smarcel * Copyright (c) 2002 Marcel Moolenaar 3106184Smarcel * Copyright (c) 2002 Hiten Mahesh Pandya 4106184Smarcel * All rights reserved. 5106184Smarcel * 6106184Smarcel * Redistribution and use in source and binary forms, with or without 7106184Smarcel * modification, are permitted provided that the following conditions 8106184Smarcel * are met: 9106184Smarcel * 1. Redistributions of source code must retain the above copyright 10106184Smarcel * notice, this list of conditions and the following disclaimer. 11106184Smarcel * 2. Redistributions in binary form must reproduce the above copyright 12106184Smarcel * notice, this list of conditions and the following disclaimer in the 13106184Smarcel * documentation and/or other materials provided with the distribution. 14106184Smarcel * 15106184Smarcel * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16106184Smarcel * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17106184Smarcel * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18106184Smarcel * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19106184Smarcel * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20106184Smarcel * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21106184Smarcel * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22106184Smarcel * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23106184Smarcel * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24106184Smarcel * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25106184Smarcel * SUCH DAMAGE. 26106184Smarcel * 27106184Smarcel * $FreeBSD: head/lib/libc/uuid/uuid_hash.c 106184 2002-10-30 03:51:00Z marcel $ 28106184Smarcel */ 29106184Smarcel 30106184Smarcel#include <uuid.h> 31106184Smarcel 32106184Smarcel/* 33106184Smarcel * uuid_hash() - generate a hash value. 34106184Smarcel * See also: 35106184Smarcel * http://www.opengroup.org/onlinepubs/009629399/uuid_hash.htm 36106184Smarcel * http://www.transarc.ibm.com/Library/documentation/dce/1.1/uuid_hash.html 37106184Smarcel */ 38106184Smarceluint16_t 39106184Smarceluuid_hash(uuid_t *u, uint32_t *status) 40106184Smarcel{ 41106184Smarcel 42106184Smarcel if (status) 43106184Smarcel *status = uuid_s_ok; 44106184Smarcel 45106184Smarcel /* 46106184Smarcel * Use the most frequently changing bits in the UUID as the hash 47106184Smarcel * value. This should yield a good enough distribution... 48106184Smarcel */ 49106184Smarcel return ((u) ? u->time_low & 0xffff : 0); 50106184Smarcel} 51