1/*	$NetBSD: humanize_number.c,v 1.8 2004/07/27 01:56:24 enami Exp $	*/
2
3/*
4 * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center, by Luke Mewburn and by Tomas Svensson.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 *    must display the following acknowledgement:
21 *      This product includes software developed by the NetBSD
22 *      Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 *    contributors may be used to endorse or promote products derived
25 *    from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40#include <sys/cdefs.h>
41
42#include <sys/types.h>
43#include <assert.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <string.h>
47#include <locale.h>
48#include <libutil.h>
49#include <stdint.h>
50#include <limits.h>
51
52int
53humanize_number(char *buf, size_t len, int64_t bytes,
54    const char *suffix, int scale, int flags)
55{
56	const char *prefixes, *sep;
57	int	b, i, r, maxscale, s1, s2, sign;
58	int64_t divisor, max;
59	// We multiply bytes by 100 to deal with rounding, so we need something
60	// big enough to hold LLONG_MAX * 100. On 64-bit we can use 128-bit wide
61	// integers with __int128_t, but on 32-bit we have to use long double.
62#ifdef __LP64__
63	__int128_t scalable = (__int128_t)bytes;
64#else
65	long double scalable = (long double)bytes;
66#endif
67	size_t	baselen;
68
69	assert(buf != NULL);
70	assert(suffix != NULL);
71	assert(scale >= 0);
72
73	if (flags & HN_DIVISOR_1000) {
74		/* SI for decimal multiplies */
75		divisor = 1000;
76		if (flags & HN_B)
77			prefixes = "B\0k\0M\0G\0T\0P\0E";
78		else
79			prefixes = "\0\0k\0M\0G\0T\0P\0E";
80	} else {
81		/*
82		 * binary multiplies
83		 * XXX IEC 60027-2 recommends Ki, Mi, Gi...
84		 */
85		divisor = 1024;
86		if (flags & HN_B)
87			prefixes = "B\0K\0M\0G\0T\0P\0E";
88		else
89			prefixes = "\0\0K\0M\0G\0T\0P\0E";
90	}
91
92#define	SCALE2PREFIX(scale)	(&prefixes[(scale) << 1])
93	maxscale = 7;
94
95	if (scale >= maxscale &&
96	    (scale & (HN_AUTOSCALE | HN_GETSCALE)) == 0)
97		return (-1);
98
99	if (buf == NULL || suffix == NULL)
100		return (-1);
101
102	if (len > 0)
103		buf[0] = '\0';
104	if (bytes < 0) {
105		sign = -1;
106		scalable *= -100;
107		baselen = 3;		/* sign, digit, prefix */
108	} else {
109		sign = 1;
110		scalable *= 100;
111		baselen = 2;		/* digit, prefix */
112	}
113	if (flags & HN_NOSPACE)
114		sep = "";
115	else {
116		sep = " ";
117		baselen++;
118	}
119	baselen += strlen(suffix);
120
121	/* Check if enough room for `x y' + suffix + `\0' */
122	if (len < baselen + 1)
123		return (-1);
124
125	if (scale & (HN_AUTOSCALE | HN_GETSCALE)) {
126		/* See if there is additional columns can be used. */
127		for (max = 100, i = len - baselen; i-- > 0;)
128			max *= 10;
129
130		for (i = 0; scalable >= max && i < maxscale; i++)
131			scalable /= divisor;
132
133		if (scale & HN_GETSCALE)
134			return (i);
135	} else
136		for (i = 0; i < scale && i < maxscale; i++)
137			scalable /= divisor;
138
139	/* If a value <= 9.9 after rounding and ... */
140	if (scalable < 995 && i > 0 && flags & HN_DECIMAL) {
141		/* baselen + \0 + .N */
142		if (len < baselen + 1 + 2)
143			return (-1);
144		b = ((int)scalable + 5) / 10;
145		s1 = b / 10;
146		s2 = b % 10;
147		r = snprintf(buf, len, "%s%d%s%d%s%s%s",
148			((sign == -1) ? "-" : ""),
149		    s1, localeconv()->decimal_point, s2,
150		    sep, SCALE2PREFIX(i), suffix);
151	} else
152		r = snprintf(buf, len, "%s%lld%s%s%s",
153		    /* LONGLONG */
154			((sign == -1) ? "-" : ""),
155		    (long long)((scalable + 50) / 100),
156		    sep, SCALE2PREFIX(i), suffix);
157
158	return (r);
159}
160