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 * $FreeBSD$ 28 */ 29 30 #include <string.h> 31 #include <uuid.h> 32 33 /* A macro used to improve the readability of uuid_compare(). */ 34 #define DIFF_RETURN(a, b, field) do { \ 35 if ((a)->field != (b)->field) \ 36 return (((a)->field < (b)->field) ? -1 : 1); \ 37 } while (0) 38 39 /* 40 * uuid_compare() - compare two UUIDs. 41 * See also: 42 * http://www.opengroup.org/onlinepubs/009629399/uuid_compare.htm 43 * 44 * NOTE: Either UUID can be NULL, meaning a nil UUID. nil UUIDs are smaller 45 * than any non-nil UUID. 46 */ 47 int32_t 48 uuid_compare(const uuid_t *a, const uuid_t *b, uint32_t *status) 49 { 50 int res; 51 52 if (status != NULL) 53 *status = uuid_s_ok; 54 55 /* Deal with NULL or equal pointers. */ 56 if (a == b) 57 return (0); 58 if (a == NULL) 59 return ((uuid_is_nil(b, NULL)) ? 0 : -1); 60 if (b == NULL) 61 return ((uuid_is_nil(a, NULL)) ? 0 : 1); 62 63 /* We have to compare the hard way. */ 64 DIFF_RETURN(a, b, time_low); 65 DIFF_RETURN(a, b, time_mid); 66 DIFF_RETURN(a, b, time_hi_and_version); 67 DIFF_RETURN(a, b, clock_seq_hi_and_reserved); 68 DIFF_RETURN(a, b, clock_seq_low); 69 70 res = memcmp(a->node, b->node, sizeof(a->node)); 71 if (res) 72 return ((res < 0) ? -1 : 1); 73 return (0); 74 } 75 76 #undef DIFF_RETURN 77