1 /*
2 * librdkafka - Apache Kafka C library
3 *
4 * Copyright (c) 2012-2018, Magnus Edenhill
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright notice,
13 * this list of conditions and the following disclaimer in the documentation
14 * and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #pragma once
30
31 #include <math.h>
32
33 /**
34 * rd_dbl_eq0(a,b,prec)
35 * Check two doubles for equality with the specified precision.
36 * Use this instead of != and == for all floats/doubles.
37 * More info:
38 * http://docs.sun.com/source/806-3568/ncg_goldberg.html
39 */
40 static RD_INLINE RD_UNUSED
rd_dbl_eq0(double a,double b,double prec)41 int rd_dbl_eq0 (double a, double b, double prec) {
42 return fabs(a - b) < prec;
43 }
44
45 /* A default 'good' double-equality precision value.
46 * This rather timid epsilon value is useful for tenths, hundreths,
47 * and thousands parts, but not anything more precis than that.
48 * If a higher precision is needed, use dbl_eq0 and dbl_eq0 directly
49 * and specify your own precision. */
50 #define RD_DBL_EPSILON 0.00001
51
52 /**
53 * rd_dbl_eq(a,b)
54 * Same as rd_dbl_eq0() above but with a predefined 'good' precision.
55 */
56 #define rd_dbl_eq(a,b) rd_dbl_eq0(a,b,RD_DBL_EPSILON)
57
58 /**
59 * rd_dbl_ne(a,b)
60 * Same as rd_dbl_eq() above but with reversed logic: not-equal.
61 */
62 #define rd_dbl_ne(a,b) (!rd_dbl_eq0(a,b,RD_DBL_EPSILON))
63
64 /**
65 * rd_dbl_zero(a)
66 * Checks if the double `a' is zero (or close enough).
67 */
68 #define rd_dbl_zero(a) rd_dbl_eq0(a,0.0,RD_DBL_EPSILON)
69