18e14c45fSSascha Wildner /* $NetBSD: humanize_number.c,v 1.14 2008/04/28 20:22:59 martin Exp $ */
2f41183adSMatthew Dillon
3f41183adSMatthew Dillon /*
4f41183adSMatthew Dillon * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
5d316f7c9SJohn Marino * Copyright 2013 John-Mark Gurney <jmg@FreeBSD.org>
6f41183adSMatthew Dillon * All rights reserved.
7f41183adSMatthew Dillon *
8f41183adSMatthew Dillon * This code is derived from software contributed to The NetBSD Foundation
9f41183adSMatthew Dillon * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
10f41183adSMatthew Dillon * NASA Ames Research Center, by Luke Mewburn and by Tomas Svensson.
11f41183adSMatthew Dillon *
12f41183adSMatthew Dillon * Redistribution and use in source and binary forms, with or without
13f41183adSMatthew Dillon * modification, are permitted provided that the following conditions
14f41183adSMatthew Dillon * are met:
15f41183adSMatthew Dillon * 1. Redistributions of source code must retain the above copyright
16f41183adSMatthew Dillon * notice, this list of conditions and the following disclaimer.
17f41183adSMatthew Dillon * 2. Redistributions in binary form must reproduce the above copyright
18f41183adSMatthew Dillon * notice, this list of conditions and the following disclaimer in the
19f41183adSMatthew Dillon * documentation and/or other materials provided with the distribution.
20f41183adSMatthew Dillon *
21f41183adSMatthew Dillon * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22f41183adSMatthew Dillon * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23f41183adSMatthew Dillon * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24f41183adSMatthew Dillon * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25f41183adSMatthew Dillon * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26f41183adSMatthew Dillon * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27f41183adSMatthew Dillon * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28f41183adSMatthew Dillon * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29f41183adSMatthew Dillon * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30f41183adSMatthew Dillon * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31f41183adSMatthew Dillon * POSSIBILITY OF SUCH DAMAGE.
32f41183adSMatthew Dillon *
33d316f7c9SJohn Marino * $FreeBSD: head/lib/libutil/humanize_number.c 256130 2013-10-07 22:22:57Z jmg $
34f41183adSMatthew Dillon */
35f41183adSMatthew Dillon
36f41183adSMatthew Dillon #include <sys/types.h>
37f41183adSMatthew Dillon #include <assert.h>
388e14c45fSSascha Wildner #include <inttypes.h>
39f41183adSMatthew Dillon #include <stdio.h>
40f41183adSMatthew Dillon #include <stdlib.h>
41f41183adSMatthew Dillon #include <string.h>
428e14c45fSSascha Wildner #include <locale.h>
43d316f7c9SJohn Marino #include <libutil.h>
44ca008f5eSChris Pressey
45d316f7c9SJohn Marino static const int maxscale = 7;
46f41183adSMatthew Dillon
47f41183adSMatthew Dillon int
humanize_number(char * buf,size_t len,int64_t quotient,const char * suffix,int scale,int flags)48d316f7c9SJohn Marino humanize_number(char *buf, size_t len, int64_t quotient,
49f41183adSMatthew Dillon const char *suffix, int scale, int flags)
50f41183adSMatthew Dillon {
51f41183adSMatthew Dillon const char *prefixes, *sep;
52d316f7c9SJohn Marino int i, r, remainder, s1, s2, sign;
53d316f7c9SJohn Marino int divisordeccut;
54f41183adSMatthew Dillon int64_t divisor, max;
55f41183adSMatthew Dillon size_t baselen;
56f41183adSMatthew Dillon
57d316f7c9SJohn Marino /* validate args */
58*70fef11bSAaron LI if (buf == NULL)
59d316f7c9SJohn Marino return (-1);
60d316f7c9SJohn Marino if (scale < 0)
61d316f7c9SJohn Marino return (-1);
62d316f7c9SJohn Marino else if (scale >= maxscale &&
63d316f7c9SJohn Marino ((scale & ~(HN_AUTOSCALE|HN_GETSCALE)) != 0))
64d316f7c9SJohn Marino return (-1);
65d316f7c9SJohn Marino if ((flags & HN_DIVISOR_1000) && (flags & HN_IEC_PREFIXES))
66d316f7c9SJohn Marino return (-1);
67d316f7c9SJohn Marino
6888b59fa5SAaron LI /* Since so many callers don't check -1, NUL terminate the buffer */
6988b59fa5SAaron LI if (len > 0)
7088b59fa5SAaron LI buf[0] = '\0';
7188b59fa5SAaron LI
72*70fef11bSAaron LI if (suffix == NULL)
73*70fef11bSAaron LI suffix = "";
74*70fef11bSAaron LI
75d316f7c9SJohn Marino /* setup parameters */
76d316f7c9SJohn Marino remainder = 0;
77d316f7c9SJohn Marino
78d316f7c9SJohn Marino if (flags & HN_IEC_PREFIXES) {
79d316f7c9SJohn Marino baselen = 2;
80d316f7c9SJohn Marino /*
81d316f7c9SJohn Marino * Use the prefixes for power of two recommended by
82d316f7c9SJohn Marino * the International Electrotechnical Commission
83d316f7c9SJohn Marino * (IEC) in IEC 80000-3 (i.e. Ki, Mi, Gi...).
84d316f7c9SJohn Marino *
85d316f7c9SJohn Marino * HN_IEC_PREFIXES implies a divisor of 1024 here
86d316f7c9SJohn Marino * (use of HN_DIVISOR_1000 would have triggered
87d316f7c9SJohn Marino * an assertion earlier).
88d316f7c9SJohn Marino */
89d316f7c9SJohn Marino divisor = 1024;
90d316f7c9SJohn Marino divisordeccut = 973; /* ceil(.95 * 1024) */
91d316f7c9SJohn Marino if (flags & HN_B)
92d316f7c9SJohn Marino prefixes = "B\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei";
93d316f7c9SJohn Marino else
94d316f7c9SJohn Marino prefixes = "\0\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei";
95d316f7c9SJohn Marino } else {
96d316f7c9SJohn Marino baselen = 1;
97d316f7c9SJohn Marino if (flags & HN_DIVISOR_1000) {
98d316f7c9SJohn Marino divisor = 1000;
99d316f7c9SJohn Marino divisordeccut = 950;
100d316f7c9SJohn Marino if (flags & HN_B)
101d316f7c9SJohn Marino prefixes = "B\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E";
102d316f7c9SJohn Marino else
103d316f7c9SJohn Marino prefixes = "\0\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E";
104d316f7c9SJohn Marino } else {
105d316f7c9SJohn Marino divisor = 1024;
106d316f7c9SJohn Marino divisordeccut = 973; /* ceil(.95 * 1024) */
107d316f7c9SJohn Marino if (flags & HN_B)
108d316f7c9SJohn Marino prefixes = "B\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E";
109d316f7c9SJohn Marino else
110d316f7c9SJohn Marino prefixes = "\0\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E";
111d316f7c9SJohn Marino }
112d316f7c9SJohn Marino }
113d316f7c9SJohn Marino
114d316f7c9SJohn Marino #define SCALE2PREFIX(scale) (&prefixes[(scale) * 3])
115d316f7c9SJohn Marino
116d316f7c9SJohn Marino if (quotient < 0) {
117f41183adSMatthew Dillon sign = -1;
118d316f7c9SJohn Marino quotient = -quotient;
119d316f7c9SJohn Marino baselen += 2; /* sign, digit */
120f41183adSMatthew Dillon } else {
121f41183adSMatthew Dillon sign = 1;
122d316f7c9SJohn Marino baselen += 1; /* digit */
123f41183adSMatthew Dillon }
124f41183adSMatthew Dillon if (flags & HN_NOSPACE)
125f41183adSMatthew Dillon sep = "";
126f41183adSMatthew Dillon else {
127f41183adSMatthew Dillon sep = " ";
128f41183adSMatthew Dillon baselen++;
129f41183adSMatthew Dillon }
130f41183adSMatthew Dillon baselen += strlen(suffix);
131f41183adSMatthew Dillon
132f41183adSMatthew Dillon /* Check if enough room for `x y' + suffix + `\0' */
133f41183adSMatthew Dillon if (len < baselen + 1)
134f41183adSMatthew Dillon return (-1);
135f41183adSMatthew Dillon
136f41183adSMatthew Dillon if (scale & (HN_AUTOSCALE | HN_GETSCALE)) {
137f41183adSMatthew Dillon /* See if there is additional columns can be used. */
138d316f7c9SJohn Marino for (max = 1, i = len - baselen; i-- > 0;)
139f41183adSMatthew Dillon max *= 10;
140f41183adSMatthew Dillon
1418e14c45fSSascha Wildner /*
1428e14c45fSSascha Wildner * Divide the number until it fits the given column.
1438e14c45fSSascha Wildner * If there will be an overflow by the rounding below,
1448e14c45fSSascha Wildner * divide once more.
1458e14c45fSSascha Wildner */
146d316f7c9SJohn Marino for (i = 0;
147d316f7c9SJohn Marino (quotient >= max || (quotient == max - 1 &&
148d316f7c9SJohn Marino remainder >= divisordeccut)) && i < maxscale; i++) {
149d316f7c9SJohn Marino remainder = quotient % divisor;
150d316f7c9SJohn Marino quotient /= divisor;
151d316f7c9SJohn Marino }
152f41183adSMatthew Dillon
153f41183adSMatthew Dillon if (scale & HN_GETSCALE)
154f41183adSMatthew Dillon return (i);
155d316f7c9SJohn Marino } else {
156d316f7c9SJohn Marino for (i = 0; i < scale && i < maxscale; i++) {
157d316f7c9SJohn Marino remainder = quotient % divisor;
158d316f7c9SJohn Marino quotient /= divisor;
159d316f7c9SJohn Marino }
160d316f7c9SJohn Marino }
161f41183adSMatthew Dillon
162d316f7c9SJohn Marino /*
163a4b1d485SMatthew Dillon * Generate base output
164d316f7c9SJohn Marino */
165a4b1d485SMatthew Dillon r = snprintf(buf, len, "%" PRId64 "%s%s%s",
166a4b1d485SMatthew Dillon sign * (quotient + (remainder + divisor / 2) / divisor),
167a4b1d485SMatthew Dillon sep, SCALE2PREFIX(i), suffix);
168a4b1d485SMatthew Dillon
169a4b1d485SMatthew Dillon if ((flags & HN_FRACTIONAL) && (u_int)r + 3 <= len && i) {
170a4b1d485SMatthew Dillon /*
171a4b1d485SMatthew Dillon * If FRACTIONAL is specified output up to two fractional
172a4b1d485SMatthew Dillon * digits, unless the value was not divided out.
173a4b1d485SMatthew Dillon */
174a4b1d485SMatthew Dillon int64_t frac;
175a4b1d485SMatthew Dillon int n;
176a4b1d485SMatthew Dillon
177a4b1d485SMatthew Dillon n = (int)len - r - 2;
178a4b1d485SMatthew Dillon frac = 1;
179a4b1d485SMatthew Dillon if (n > 2) /* max 2 fractional digits */
180a4b1d485SMatthew Dillon n = 2;
181a4b1d485SMatthew Dillon
182a4b1d485SMatthew Dillon while (n) {
183a4b1d485SMatthew Dillon frac = frac * 10;
184a4b1d485SMatthew Dillon --n;
185a4b1d485SMatthew Dillon }
186a4b1d485SMatthew Dillon s1 = (int)quotient + ((remainder * frac + divisor / 2) /
187a4b1d485SMatthew Dillon divisor / frac);
188a4b1d485SMatthew Dillon s2 = ((remainder * frac + divisor / 2) / divisor) % frac;
189a4b1d485SMatthew Dillon r = snprintf(buf, len, "%d%s%d%s%s%s",
190a4b1d485SMatthew Dillon sign * s1, localeconv()->decimal_point, s2,
191a4b1d485SMatthew Dillon sep, SCALE2PREFIX(i), suffix);
192a4b1d485SMatthew Dillon } else if ((flags & HN_DECIMAL) && (u_int)r + 3 <= len &&
193a4b1d485SMatthew Dillon (((quotient == 9 && remainder < divisordeccut) ||
194a4b1d485SMatthew Dillon quotient < 9) && i > 0)) {
195a4b1d485SMatthew Dillon /*
196a4b1d485SMatthew Dillon * If DECIMAL is specified and the value is <= 9.9 after
197a4b1d485SMatthew Dillon * rounding, and it fits, add one fractional digit.
198a4b1d485SMatthew Dillon */
199d316f7c9SJohn Marino s1 = (int)quotient + ((remainder * 10 + divisor / 2) /
200d316f7c9SJohn Marino divisor / 10);
201d316f7c9SJohn Marino s2 = ((remainder * 10 + divisor / 2) / divisor) % 10;
202f41183adSMatthew Dillon r = snprintf(buf, len, "%d%s%d%s%s%s",
203f41183adSMatthew Dillon sign * s1, localeconv()->decimal_point, s2,
204f41183adSMatthew Dillon sep, SCALE2PREFIX(i), suffix);
205a4b1d485SMatthew Dillon }
206f41183adSMatthew Dillon return (r);
207f41183adSMatthew Dillon }
208