uuid_compare.c revision 118668 
1/*-
2 * Copyright (c) 2002 Marcel Moolenaar
3 * Copyright (c) 2002 Hiten Mahesh Pandya
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD: head/lib/libc/uuid/uuid_compare.c 118668 2003-08-08 19:03:37Z marcel $
28 */
29
30#include <string.h>
31#include <uuid.h>
32
33/*
34 * uuid_compare() - compare two UUIDs.
35 * See also:
36 *	http://www.opengroup.org/onlinepubs/009629399/uuid_compare.htm
37 *	http://www.transarc.ibm.com/Library/documentation/dce/1.1/uuid_compare.html
38 *
39 * NOTE: Either UUID can be NULL, meaning a nil UUID. nil UUIDs are smaller
40 *	 than any non-nil UUID.
41 */
42int32_t
43uuid_compare(uuid_t *a, uuid_t *b, uint32_t *status)
44{
45	int res;
46
47	if (status != NULL)
48		*status = uuid_s_ok;
49
50	/* Deal with NULL or equal pointers. */
51	if (a == b)
52		return (0);
53	if (a == NULL)
54		return ((uuid_is_nil(b, NULL)) ? 0 : -1);
55	if (b == NULL)
56		return ((uuid_is_nil(a, NULL)) ? 0 : 1);
57
58	/* We have to compare the hard way. */
59	res = (int)((int64_t)a->time_low - (int64_t)b->time_low);
60	if (res)
61		return ((res < 0) ? -1 : 1);
62	res = (int)a->time_mid - (int)b->time_mid;
63	if (res)
64		return ((res < 0) ? -1 : 1);
65	res = (int)a->time_hi_and_version - (int)b->time_hi_and_version;
66	if (res)
67		return ((res < 0) ? -1 : 1);
68	res = (int)a->clock_seq_hi_and_reserved -
69	    (int)b->clock_seq_hi_and_reserved;
70	if (res)
71		return ((res < 0) ? -1 : 1);
72	res = (int)a->clock_seq_low - (int)b->clock_seq_low;
73	if (res)
74		return ((res < 0) ? -1 : 1);
75	res = memcmp(a->node, b->node, sizeof(a->node));
76	if (res)
77		return ((res < 0) ? -1 : 1);
78	return (0);
79}
80