humanize_number.c revision 1.17 1 1.17 christos /* $NetBSD: humanize_number.c,v 1.17 2017/04/13 17:45:56 christos Exp $ */
2 1.1 abs
3 1.1 abs /*
4 1.1 abs * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
5 1.1 abs * All rights reserved.
6 1.1 abs *
7 1.1 abs * This code is derived from software contributed to The NetBSD Foundation
8 1.1 abs * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 1.1 abs * NASA Ames Research Center, by Luke Mewburn and by Tomas Svensson.
10 1.1 abs *
11 1.1 abs * Redistribution and use in source and binary forms, with or without
12 1.1 abs * modification, are permitted provided that the following conditions
13 1.1 abs * are met:
14 1.1 abs * 1. Redistributions of source code must retain the above copyright
15 1.1 abs * notice, this list of conditions and the following disclaimer.
16 1.1 abs * 2. Redistributions in binary form must reproduce the above copyright
17 1.1 abs * notice, this list of conditions and the following disclaimer in the
18 1.1 abs * documentation and/or other materials provided with the distribution.
19 1.1 abs *
20 1.1 abs * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 1.1 abs * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 1.1 abs * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 1.1 abs * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 1.1 abs * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 1.1 abs * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 1.1 abs * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 1.1 abs * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 1.1 abs * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 1.1 abs * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 1.1 abs * POSSIBILITY OF SUCH DAMAGE.
31 1.1 abs */
32 1.1 abs
33 1.1 abs #include <sys/cdefs.h>
34 1.10 christos #if defined(LIBC_SCCS) && !defined(lint)
35 1.17 christos __RCSID("$NetBSD: humanize_number.c,v 1.17 2017/04/13 17:45:56 christos Exp $");
36 1.10 christos #endif /* LIBC_SCCS and not lint */
37 1.1 abs
38 1.9 kleink #include "namespace.h"
39 1.1 abs #include <assert.h>
40 1.11 simonb #include <inttypes.h>
41 1.1 abs #include <stdio.h>
42 1.1 abs #include <stdlib.h>
43 1.1 abs #include <string.h>
44 1.1 abs #include <locale.h>
45 1.1 abs
46 1.1 abs int
47 1.1 abs humanize_number(char *buf, size_t len, int64_t bytes,
48 1.1 abs const char *suffix, int scale, int flags)
49 1.1 abs {
50 1.8 enami const char *prefixes, *sep;
51 1.15 christos int b, r, s1, s2, sign;
52 1.16 christos int64_t divisor, max, post = 1;
53 1.15 christos size_t i, baselen, maxscale;
54 1.1 abs
55 1.1 abs _DIAGASSERT(buf != NULL);
56 1.1 abs _DIAGASSERT(suffix != NULL);
57 1.4 thorpej _DIAGASSERT(scale >= 0);
58 1.1 abs
59 1.3 drochner if (flags & HN_DIVISOR_1000) {
60 1.3 drochner /* SI for decimal multiplies */
61 1.3 drochner divisor = 1000;
62 1.8 enami if (flags & HN_B)
63 1.8 enami prefixes = "B\0k\0M\0G\0T\0P\0E";
64 1.8 enami else
65 1.8 enami prefixes = "\0\0k\0M\0G\0T\0P\0E";
66 1.3 drochner } else {
67 1.3 drochner /*
68 1.3 drochner * binary multiplies
69 1.3 drochner * XXX IEC 60027-2 recommends Ki, Mi, Gi...
70 1.3 drochner */
71 1.3 drochner divisor = 1024;
72 1.8 enami if (flags & HN_B)
73 1.8 enami prefixes = "B\0K\0M\0G\0T\0P\0E";
74 1.8 enami else
75 1.8 enami prefixes = "\0\0K\0M\0G\0T\0P\0E";
76 1.3 drochner }
77 1.3 drochner
78 1.8 enami #define SCALE2PREFIX(scale) (&prefixes[(scale) << 1])
79 1.17 christos maxscale = 6;
80 1.8 enami
81 1.17 christos if ((size_t)scale > maxscale &&
82 1.8 enami (scale & (HN_AUTOSCALE | HN_GETSCALE)) == 0)
83 1.1 abs return (-1);
84 1.1 abs
85 1.1 abs if (buf == NULL || suffix == NULL)
86 1.1 abs return (-1);
87 1.1 abs
88 1.1 abs if (len > 0)
89 1.1 abs buf[0] = '\0';
90 1.1 abs if (bytes < 0) {
91 1.1 abs sign = -1;
92 1.8 enami baselen = 3; /* sign, digit, prefix */
93 1.16 christos if (-bytes < INT64_MAX / 100)
94 1.16 christos bytes *= -100;
95 1.16 christos else {
96 1.16 christos bytes = -bytes;
97 1.16 christos post = 100;
98 1.16 christos baselen += 2;
99 1.16 christos }
100 1.1 abs } else {
101 1.1 abs sign = 1;
102 1.8 enami baselen = 2; /* digit, prefix */
103 1.16 christos if (bytes < INT64_MAX / 100)
104 1.16 christos bytes *= 100;
105 1.16 christos else {
106 1.16 christos post = 100;
107 1.16 christos baselen += 2;
108 1.16 christos }
109 1.1 abs }
110 1.8 enami if (flags & HN_NOSPACE)
111 1.8 enami sep = "";
112 1.8 enami else {
113 1.8 enami sep = " ";
114 1.8 enami baselen++;
115 1.8 enami }
116 1.8 enami baselen += strlen(suffix);
117 1.1 abs
118 1.8 enami /* Check if enough room for `x y' + suffix + `\0' */
119 1.8 enami if (len < baselen + 1)
120 1.1 abs return (-1);
121 1.1 abs
122 1.8 enami if (scale & (HN_AUTOSCALE | HN_GETSCALE)) {
123 1.8 enami /* See if there is additional columns can be used. */
124 1.8 enami for (max = 100, i = len - baselen; i-- > 0;)
125 1.8 enami max *= 10;
126 1.1 abs
127 1.12 enami /*
128 1.12 enami * Divide the number until it fits the given column.
129 1.12 enami * If there will be an overflow by the rounding below,
130 1.12 enami * divide once more.
131 1.12 enami */
132 1.12 enami for (i = 0; bytes >= max - 50 && i < maxscale; i++)
133 1.1 abs bytes /= divisor;
134 1.8 enami
135 1.15 christos if (scale & HN_GETSCALE) {
136 1.15 christos _DIAGASSERT(__type_fit(int, i));
137 1.15 christos return (int)i;
138 1.15 christos }
139 1.8 enami } else
140 1.15 christos for (i = 0; i < (size_t)scale && i < maxscale; i++)
141 1.1 abs bytes /= divisor;
142 1.16 christos bytes *= post;
143 1.1 abs
144 1.8 enami /* If a value <= 9.9 after rounding and ... */
145 1.8 enami if (bytes < 995 && i > 0 && flags & HN_DECIMAL) {
146 1.8 enami /* baselen + \0 + .N */
147 1.8 enami if (len < baselen + 1 + 2)
148 1.1 abs return (-1);
149 1.8 enami b = ((int)bytes + 5) / 10;
150 1.8 enami s1 = b / 10;
151 1.8 enami s2 = b % 10;
152 1.8 enami r = snprintf(buf, len, "%d%s%d%s%s%s",
153 1.8 enami sign * s1, localeconv()->decimal_point, s2,
154 1.8 enami sep, SCALE2PREFIX(i), suffix);
155 1.1 abs } else
156 1.11 simonb r = snprintf(buf, len, "%" PRId64 "%s%s%s",
157 1.11 simonb sign * ((bytes + 50) / 100),
158 1.8 enami sep, SCALE2PREFIX(i), suffix);
159 1.1 abs
160 1.1 abs return (r);
161 1.1 abs }
162