1 /* $NetBSD: humanize_number.c,v 1.14 2008/04/28 20:22:59 martin Exp $ */
4 * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
5 * Copyright 2013 John-Mark Gurney <jmg@FreeBSD.org>
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
10 * NASA Ames Research Center, by Luke Mewburn and by Tomas Svensson.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
21 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
37 #include <sys/types.h>
46 static const int maxscale = 7;
49 humanize_number(char *buf, size_t len, int64_t quotient,
50 const char *suffix, int scale, int flags)
52 const char *prefixes, *sep;
53 int i, r, remainder, s1, s2, sign;
58 /* Since so many callers don't check -1, NUL terminate the buffer */
63 if (buf == NULL || suffix == NULL)
67 else if (scale >= maxscale &&
68 ((scale & ~(HN_AUTOSCALE|HN_GETSCALE)) != 0))
70 if ((flags & HN_DIVISOR_1000) && (flags & HN_IEC_PREFIXES))
73 /* setup parameters */
76 if (flags & HN_IEC_PREFIXES) {
79 * Use the prefixes for power of two recommended by
80 * the International Electrotechnical Commission
81 * (IEC) in IEC 80000-3 (i.e. Ki, Mi, Gi...).
83 * HN_IEC_PREFIXES implies a divisor of 1024 here
84 * (use of HN_DIVISOR_1000 would have triggered
85 * an assertion earlier).
88 divisordeccut = 973; /* ceil(.95 * 1024) */
90 prefixes = "B\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei";
92 prefixes = "\0\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei";
95 if (flags & HN_DIVISOR_1000) {
99 prefixes = "B\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E";
101 prefixes = "\0\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E";
104 divisordeccut = 973; /* ceil(.95 * 1024) */
106 prefixes = "B\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E";
108 prefixes = "\0\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E";
112 #define SCALE2PREFIX(scale) (&prefixes[(scale) * 3])
116 quotient = -quotient;
117 baselen += 2; /* sign, digit */
120 baselen += 1; /* digit */
122 if (flags & HN_NOSPACE)
128 baselen += strlen(suffix);
130 /* Check if enough room for `x y' + suffix + `\0' */
131 if (len < baselen + 1)
134 if (scale & (HN_AUTOSCALE | HN_GETSCALE)) {
135 /* See if there is additional columns can be used. */
136 for (max = 1, i = len - baselen; i-- > 0;)
140 * Divide the number until it fits the given column.
141 * If there will be an overflow by the rounding below,
145 (quotient >= max || (quotient == max - 1 &&
146 remainder >= divisordeccut)) && i < maxscale; i++) {
147 remainder = quotient % divisor;
151 if (scale & HN_GETSCALE)
154 for (i = 0; i < scale && i < maxscale; i++) {
155 remainder = quotient % divisor;
160 /* If a value <= 9.9 after rounding and ... */
162 * XXX - should we make sure there is enough space for the decimal
163 * place and if not, don't do HN_DECIMAL?
165 if (((quotient == 9 && remainder < divisordeccut) || quotient < 9) &&
166 i > 0 && flags & HN_DECIMAL) {
167 s1 = (int)quotient + ((remainder * 10 + divisor / 2) /
169 s2 = ((remainder * 10 + divisor / 2) / divisor) % 10;
170 r = snprintf(buf, len, "%d%s%d%s%s%s",
171 sign * s1, localeconv()->decimal_point, s2,
172 sep, SCALE2PREFIX(i), suffix);
174 r = snprintf(buf, len, "%" PRId64 "%s%s%s",
175 sign * (quotient + (remainder + divisor / 2) / divisor),
176 sep, SCALE2PREFIX(i), suffix);