uuid_compare.c revision 139601 
1/*-
2 * Copyright (c) 2002,2005 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 139601 2005-01-03 02:56:15Z 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 *
38 * NOTE: Either UUID can be NULL, meaning a nil UUID. nil UUIDs are smaller
39 *	 than any non-nil UUID.
40 */
41int32_t
42uuid_compare(const uuid_t *a, const uuid_t *b, uint32_t *status)
43{
44	int res;
45
46	if (status != NULL)
47		*status = uuid_s_ok;
48
49	/* Deal with NULL or equal pointers. */
50	if (a == b)
51		return (0);
52	if (a == NULL)
53		return ((uuid_is_nil(b, NULL)) ? 0 : -1);
54	if (b == NULL)
55		return ((uuid_is_nil(a, NULL)) ? 0 : 1);
56
57	/* We have to compare the hard way. */
58	res = (int)((int64_t)a->time_low - (int64_t)b->time_low);
59	if (res)
60		return ((res < 0) ? -1 : 1);
61	res = (int)a->time_mid - (int)b->time_mid;
62	if (res)
63		return ((res < 0) ? -1 : 1);
64	res = (int)a->time_hi_and_version - (int)b->time_hi_and_version;
65	if (res)
66		return ((res < 0) ? -1 : 1);
67	res = (int)a->clock_seq_hi_and_reserved -
68	    (int)b->clock_seq_hi_and_reserved;
69	if (res)
70		return ((res < 0) ? -1 : 1);
71	res = (int)a->clock_seq_low - (int)b->clock_seq_low;
72	if (res)
73		return ((res < 0) ? -1 : 1);
74	res = memcmp(a->node, b->node, sizeof(a->node));
75	if (res)
76		return ((res < 0) ? -1 : 1);
77	return (0);
78}
79