xref: /dragonfly/lib/libutil/humanize_number.c (revision 1847e88f)
1 /*	$NetBSD: humanize_number.c,v 1.8 2004/07/27 01:56:24 enami Exp $	*/
2 /* $DragonFly: src/lib/libutil/humanize_number.c,v 1.2 2005/03/04 04:31:11 cpressey Exp $ */
3 
4 /*
5  * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
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.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
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.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *      This product includes software developed by the NetBSD
23  *      Foundation, Inc. and its contributors.
24  * 4. Neither the name of The NetBSD Foundation nor the names of its
25  *    contributors may be used to endorse or promote products derived
26  *    from this software without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
29  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
30  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
31  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
32  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38  * POSSIBILITY OF SUCH DAMAGE.
39  *
40  * $FreeBSD: /repoman/r/ncvs/src/lib/libutil/humanize_number.c,v 1.1.2.1 2004/09/28 18:24:10 pjd Exp $
41  */
42 
43 #include <sys/cdefs.h>
44 #include <sys/types.h>
45 
46 #include <assert.h>
47 #include <locale.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 
52 #include "libutil.h"
53 
54 int
55 humanize_number(char *buf, size_t len, int64_t bytes,
56     const char *suffix, int scale, int flags)
57 {
58 	const char *prefixes, *sep;
59 	int	b, i, r, maxscale, s1, s2, sign;
60 	int64_t	divisor, max;
61 	size_t	baselen;
62 
63 	assert(buf != NULL);
64 	assert(suffix != NULL);
65 	assert(scale >= 0);
66 
67 	if (flags & HN_DIVISOR_1000) {
68 		/* SI for decimal multiplies */
69 		divisor = 1000;
70 		if (flags & HN_B)
71 			prefixes = "B\0k\0M\0G\0T\0P\0E";
72 		else
73 			prefixes = "\0\0k\0M\0G\0T\0P\0E";
74 	} else {
75 		/*
76 		 * binary multiplies
77 		 * XXX IEC 60027-2 recommends Ki, Mi, Gi...
78 		 */
79 		divisor = 1024;
80 		if (flags & HN_B)
81 			prefixes = "B\0K\0M\0G\0T\0P\0E";
82 		else
83 			prefixes = "\0\0K\0M\0G\0T\0P\0E";
84 	}
85 
86 #define	SCALE2PREFIX(scale)	(&prefixes[(scale) << 1])
87 	maxscale = 7;
88 
89 	if (scale >= maxscale &&
90 	    (scale & (HN_AUTOSCALE | HN_GETSCALE)) == 0)
91 		return (-1);
92 
93 	if (buf == NULL || suffix == NULL)
94 		return (-1);
95 
96 	if (len > 0)
97 		buf[0] = '\0';
98 	if (bytes < 0) {
99 		sign = -1;
100 		bytes *= -100;
101 		baselen = 3;		/* sign, digit, prefix */
102 	} else {
103 		sign = 1;
104 		bytes *= 100;
105 		baselen = 2;		/* digit, prefix */
106 	}
107 	if (flags & HN_NOSPACE)
108 		sep = "";
109 	else {
110 		sep = " ";
111 		baselen++;
112 	}
113 	baselen += strlen(suffix);
114 
115 	/* Check if enough room for `x y' + suffix + `\0' */
116 	if (len < baselen + 1)
117 		return (-1);
118 
119 	if (scale & (HN_AUTOSCALE | HN_GETSCALE)) {
120 		/* See if there is additional columns can be used. */
121 		for (max = 100, i = len - baselen; i-- > 0;)
122 			max *= 10;
123 
124 		for (i = 0; bytes >= max && i < maxscale; i++)
125 			bytes /= divisor;
126 
127 		if (scale & HN_GETSCALE)
128 			return (i);
129 	} else
130 		for (i = 0; i < scale && i < maxscale; i++)
131 			bytes /= divisor;
132 
133 	/* If a value <= 9.9 after rounding and ... */
134 	if (bytes < 995 && i > 0 && flags & HN_DECIMAL) {
135 		/* baselen + \0 + .N */
136 		if (len < baselen + 1 + 2)
137 			return (-1);
138 		b = ((int)bytes + 5) / 10;
139 		s1 = b / 10;
140 		s2 = b % 10;
141 		r = snprintf(buf, len, "%d%s%d%s%s%s",
142 		    sign * s1, localeconv()->decimal_point, s2,
143 		    sep, SCALE2PREFIX(i), suffix);
144 	} else
145 		r = snprintf(buf, len, "%lld%s%s%s",
146 		    /* LONGLONG */
147 		    (long long)(sign * ((bytes + 50) / 100)),
148 		    sep, SCALE2PREFIX(i), suffix);
149 
150 	return (r);
151 }
152