xref: /dflybsd-src/lib/libc/uuid/uuid_compare.c (revision 86d7f5d305c6adaa56ff4582ece9859d73106103)
186d7f5d3SJohn Marino /*-
286d7f5d3SJohn Marino  * Copyright (c) 2002,2005 Marcel Moolenaar
386d7f5d3SJohn Marino  * Copyright (c) 2002 Hiten Mahesh Pandya
486d7f5d3SJohn Marino  * All rights reserved.
586d7f5d3SJohn Marino  *
686d7f5d3SJohn Marino  * Redistribution and use in source and binary forms, with or without
786d7f5d3SJohn Marino  * modification, are permitted provided that the following conditions
886d7f5d3SJohn Marino  * are met:
986d7f5d3SJohn Marino  * 1. Redistributions of source code must retain the above copyright
1086d7f5d3SJohn Marino  *    notice, this list of conditions and the following disclaimer.
1186d7f5d3SJohn Marino  * 2. Redistributions in binary form must reproduce the above copyright
1286d7f5d3SJohn Marino  *    notice, this list of conditions and the following disclaimer in the
1386d7f5d3SJohn Marino  *    documentation and/or other materials provided with the distribution.
1486d7f5d3SJohn Marino  *
1586d7f5d3SJohn Marino  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
1686d7f5d3SJohn Marino  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1786d7f5d3SJohn Marino  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1886d7f5d3SJohn Marino  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
1986d7f5d3SJohn Marino  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2086d7f5d3SJohn Marino  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2186d7f5d3SJohn Marino  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2286d7f5d3SJohn Marino  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2386d7f5d3SJohn Marino  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2486d7f5d3SJohn Marino  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2586d7f5d3SJohn Marino  * SUCH DAMAGE.
2686d7f5d3SJohn Marino  *
2786d7f5d3SJohn Marino  * $FreeBSD: src/lib/libc/uuid/uuid_compare.c,v 1.6 2007/04/05 02:07:33 delphij Exp $
2886d7f5d3SJohn Marino  * $DragonFly: src/lib/libc/uuid/uuid_compare.c,v 1.1 2007/06/16 19:57:14 dillon Exp $
2986d7f5d3SJohn Marino  */
3086d7f5d3SJohn Marino 
3186d7f5d3SJohn Marino #include <string.h>
3286d7f5d3SJohn Marino #include <uuid.h>
3386d7f5d3SJohn Marino 
3486d7f5d3SJohn Marino /* A macro used to improve the readability of uuid_compare(). */
3586d7f5d3SJohn Marino #define DIFF_RETURN(a, b, field)	do {			\
3686d7f5d3SJohn Marino 	if ((a)->field != (b)->field)				\
3786d7f5d3SJohn Marino 		return (((a)->field < (b)->field) ? -1 : 1);	\
3886d7f5d3SJohn Marino } while (0)
3986d7f5d3SJohn Marino 
4086d7f5d3SJohn Marino /*
4186d7f5d3SJohn Marino  * uuid_compare() - compare two UUIDs.
4286d7f5d3SJohn Marino  * See also:
4386d7f5d3SJohn Marino  *	http://www.opengroup.org/onlinepubs/009629399/uuid_compare.htm
4486d7f5d3SJohn Marino  *
4586d7f5d3SJohn Marino  * NOTE: Either UUID can be NULL, meaning a nil UUID. nil UUIDs are smaller
4686d7f5d3SJohn Marino  *	 than any non-nil UUID.
4786d7f5d3SJohn Marino  */
4886d7f5d3SJohn Marino int32_t
uuid_compare(const uuid_t * a,const uuid_t * b,uint32_t * status)4986d7f5d3SJohn Marino uuid_compare(const uuid_t *a, const uuid_t *b, uint32_t *status)
5086d7f5d3SJohn Marino {
5186d7f5d3SJohn Marino 	int	res;
5286d7f5d3SJohn Marino 
5386d7f5d3SJohn Marino 	if (status != NULL)
5486d7f5d3SJohn Marino 		*status = uuid_s_ok;
5586d7f5d3SJohn Marino 
5686d7f5d3SJohn Marino 	/* Deal with NULL or equal pointers. */
5786d7f5d3SJohn Marino 	if (a == b)
5886d7f5d3SJohn Marino 		return (0);
5986d7f5d3SJohn Marino 	if (a == NULL)
6086d7f5d3SJohn Marino 		return ((uuid_is_nil(b, NULL)) ? 0 : -1);
6186d7f5d3SJohn Marino 	if (b == NULL)
6286d7f5d3SJohn Marino 		return ((uuid_is_nil(a, NULL)) ? 0 : 1);
6386d7f5d3SJohn Marino 
6486d7f5d3SJohn Marino 	/* We have to compare the hard way. */
6586d7f5d3SJohn Marino 	DIFF_RETURN(a, b, time_low);
6686d7f5d3SJohn Marino 	DIFF_RETURN(a, b, time_mid);
6786d7f5d3SJohn Marino 	DIFF_RETURN(a, b, time_hi_and_version);
6886d7f5d3SJohn Marino 	DIFF_RETURN(a, b, clock_seq_hi_and_reserved);
6986d7f5d3SJohn Marino 	DIFF_RETURN(a, b, clock_seq_low);
7086d7f5d3SJohn Marino 
7186d7f5d3SJohn Marino 	res = memcmp(a->node, b->node, sizeof(a->node));
7286d7f5d3SJohn Marino 	if (res)
7386d7f5d3SJohn Marino 		return ((res < 0) ? -1 : 1);
7486d7f5d3SJohn Marino 	return (0);
7586d7f5d3SJohn Marino }
7686d7f5d3SJohn Marino 
7786d7f5d3SJohn Marino #undef DIFF_RETURN
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