1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
/* scales, for libreswan
*
* Copyright (C) 2022-2024 Andrew Cagney <cagney@gnu.org>
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Library General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <https://www.gnu.org/licenses/lgpl-2.1.txt>.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
* License for more details.
*
*/
#include <string.h>
#include "scale.h"
#include "lswcdefs.h"
#include "jambuf.h"
#include "lswlog.h"
const struct scale *ttoscale(shunk_t cursor, const struct scales *scales,
unsigned default_scale)
{
if (cursor.len == 0) {
/* default scaling */
return &scales->scale.list[default_scale];
}
FOR_EACH_ITEM(scale, &scales->scale) {
if (hunk_strcaseeq(cursor, scale->suffix)) {
return scale;
}
}
return NULL;
}
/*
* This does not work for things like 30/60 seconds
*/
size_t jam_decimal(struct jambuf *buf, uintmax_t decimal,
uintmax_t numerator, uintmax_t denominator)
{
size_t s = 0;
const unsigned base = 10;
s += jam(buf, "%ju", decimal);
if (numerator == 0) {
return s;
}
if (numerator >= denominator) {
/* should not be called */
s += jam(buf, ".%ju/%ju", numerator, denominator);
return s;
}
/* strip trailing zeros */
while (numerator % base == 0 &&
denominator % base == 0) {
numerator /= base;
denominator /= base;
}
/* determine precision */
unsigned precision = 0;
while (denominator % base == 0) {
denominator /= base;
precision += 1;
}
s += jam(buf, ".%0*ju", precision, numerator);
return s;
}
err_t scale_decimal(const struct scale *scale, uintmax_t decimal,
uintmax_t numerator, uintmax_t denominator,
uintmax_t *value)
{
ldbgf(DBG_TMI, &global_logger,
"%s() decimal=%ju numerator=%ju denominator=%ju "PRI_SCALE"\n",
__func__, decimal, numerator, denominator, pri_scale(scale));
/*
* Check that scaling DECIMAL doesn't overflow.
*/
if (UINTMAX_MAX / scale->multiplier < decimal) {
return "overflow";
}
*value = decimal * scale->multiplier;
if (numerator > 0 && denominator > 0) {
if (denominator > scale->multiplier) {
return "underflow";
}
/* fails on really small fractions? */
(*value) += (numerator * (scale->multiplier / denominator));
}
return NULL;
}
|
