lib/libc/uuid/uuid_compare.c

   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 }