freebsd-dev/lib/libc/uuid/uuid_compare.c
Marcel Moolenaar 65393a863e Implement DCE 1.1 compliant UUID functions. Immediate use of these
functions is expected for uuidgen(1), mca(8) and gpt(8). Given the
generic use of UUIDs beyond the scope of the DCE 1.1 specification,
visibility of the data structure at all levels of the machine,
including firmware and the wish to not create a permanent build-
time FreeBSD-ism for DCE compliant applications by creating a new
library, it was decided that libc would be the least inappropriate
place. Also, because the UUID functions live in libc under IRIX as
well, we have maximized our portability and left as many options
open as possible.

This implementation introduces an extension not found in the
specification: the status parameter is allowed to be a NULL-
pointer. The reason for introducing the extension is because
the status is almost never of any use.

The manpage that's part of this commit is a minimal place-holder
and is further fleshed-out in the near future.

Approved by: re@
Contributed by: Hiten Mahesh Pandya <hiten@unixdaemons.com>
Sponsored by: marcel :-)
Tested on: alpha, i386, ia64
2002-10-30 03:51:00 +00:00

77 lines
2.6 KiB
C

/*-
* Copyright (c) 2002 Marcel Moolenaar
* Copyright (c) 2002 Hiten Mahesh Pandya
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <string.h>
#include <uuid.h>
/*
* uuid_compare() - compare two UUIDs.
* See also:
* http://www.opengroup.org/onlinepubs/009629399/uuid_compare.htm
* http://www.transarc.ibm.com/Library/documentation/dce/1.1/uuid_compare.html
*
* NOTE: Either UUID can be NULL, meaning a nil UUID. nil UUIDs are smaller
* than any non-nil UUID.
*/
int32_t
uuid_compare(uuid_t *a, uuid_t *b, uint32_t *status)
{
int res;
if (status != NULL)
*status = uuid_s_ok;
/* Deal with NULL or equal pointers. */
if (a == b)
return (0);
if (a == NULL)
return ((uuid_is_nil(b, NULL)) ? 0 : -1);
if (b == NULL)
return ((uuid_is_nil(a, NULL)) ? 0 : 1);
/* We have to compare the hard way. */
res = (int)((int64_t)a->time_low - (int64_t)b->time_low);
if (res)
return ((res < 0) ? -1 : 1);
res = (int)a->time_mid - (int)b->time_mid;
if (res)
return ((res < 0) ? -1 : 1);
res = (int)a->time_hi_and_version - (int)b->time_hi_and_version;
if (res)
return ((res < 0) ? -1 : 1);
res = (int)a->clock_seq_hi_and_reserved -
(int)b->clock_seq_hi_and_reserved;
if (res)
return ((res < 0) ? -1 : 1);
res = (int)a->clock_seq_low - (int)b->clock_seq_low;
if (res)
return ((res < 0) ? -1 : 1);
return (memcmp(a->node, b->node, sizeof(uuid_t)));
}