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      1 /*	$NetBSD: uuid_compare.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_compare.c,v 1.3 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_compare.c,v 1.2 2008/04/23 07:52:32 plunky Exp $");
     35 #endif
     36 
     37 #include "namespace.h"
     38 
     39 #include <string.h>
     40 #include <uuid.h>
     41 
     42 /*
     43  * uuid_compare() - compare two UUIDs.
     44  * See also:
     45  *	http://www.opengroup.org/onlinepubs/009629399/uuid_compare.htm
     46  *
     47  * NOTE: Either UUID can be NULL, meaning a nil UUID. nil UUIDs are smaller
     48  *	 than any non-nil UUID.
     49  */
     50 int32_t
     51 uuid_compare(const uuid_t *a, const uuid_t *b, uint32_t *status)
     52 {
     53 	int res;
     54 
     55 	if (status != NULL)
     56 		*status = uuid_s_ok;
     57 
     58 	/* Deal with NULL or equal pointers. */
     59 	if (a == b)
     60 		return (0);
     61 	if (a == NULL)
     62 		return ((uuid_is_nil(b, NULL)) ? 0 : -1);
     63 	if (b == NULL)
     64 		return ((uuid_is_nil(a, NULL)) ? 0 : 1);
     65 
     66 	/* We have to compare the hard way. */
     67 	res = (int)((int64_t)a->time_low - (int64_t)b->time_low);
     68 	if (res)
     69 		return ((res < 0) ? -1 : 1);
     70 	res = (int)a->time_mid - (int)b->time_mid;
     71 	if (res)
     72 		return ((res < 0) ? -1 : 1);
     73 	res = (int)a->time_hi_and_version - (int)b->time_hi_and_version;
     74 	if (res)
     75 		return ((res < 0) ? -1 : 1);
     76 	res = (int)a->clock_seq_hi_and_reserved -
     77 	    (int)b->clock_seq_hi_and_reserved;
     78 	if (res)
     79 		return ((res < 0) ? -1 : 1);
     80 	res = (int)a->clock_seq_low - (int)b->clock_seq_low;
     81 	if (res)
     82 		return ((res < 0) ? -1 : 1);
     83 	res = memcmp(a->node, b->node, sizeof(a->node));
     84 	if (res)
     85 		return ((res < 0) ? -1 : 1);
     86 	return (0);
     87 }
     88