1 /* $NetBSD: humanize_number.c,v 1.14 2008/04/28 20:22:59 martin Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 5 * 6 * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc. 7 * Copyright 2013 John-Mark Gurney <jmg@FreeBSD.org> 8 * All rights reserved. 9 * 10 * This code is derived from software contributed to The NetBSD Foundation 11 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 12 * NASA Ames Research Center, by Luke Mewburn and by Tomas Svensson. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include <sys/types.h> 40 #include <assert.h> 41 #include <inttypes.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <locale.h> 46 #include <libutil.h> 47 48 static const int maxscale = 6; 49 50 int 51 humanize_number(char *buf, size_t len, int64_t quotient, 52 const char *suffix, int scale, int flags) 53 { 54 const char *prefixes, *sep; 55 int i, r, remainder, s1, s2, sign; 56 int divisordeccut; 57 int64_t divisor, max; 58 size_t baselen; 59 60 /* Since so many callers don't check -1, NUL terminate the buffer */ 61 if (len > 0) 62 buf[0] = '\0'; 63 64 /* validate args */ 65 if (buf == NULL || suffix == NULL) 66 return (-1); 67 if (scale < 0) 68 return (-1); 69 else if (scale > maxscale && 70 ((scale & ~(HN_AUTOSCALE|HN_GETSCALE)) != 0)) 71 return (-1); 72 if ((flags & HN_DIVISOR_1000) && (flags & HN_IEC_PREFIXES)) 73 return (-1); 74 75 /* setup parameters */ 76 remainder = 0; 77 78 if (flags & HN_IEC_PREFIXES) { 79 baselen = 2; 80 /* 81 * Use the prefixes for power of two recommended by 82 * the International Electrotechnical Commission 83 * (IEC) in IEC 80000-3 (i.e. Ki, Mi, Gi...). 84 * 85 * HN_IEC_PREFIXES implies a divisor of 1024 here 86 * (use of HN_DIVISOR_1000 would have triggered 87 * an assertion earlier). 88 */ 89 divisor = 1024; 90 divisordeccut = 973; /* ceil(.95 * 1024) */ 91 if (flags & HN_B) 92 prefixes = "B\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei"; 93 else 94 prefixes = "\0\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei"; 95 } else { 96 baselen = 1; 97 if (flags & HN_DIVISOR_1000) { 98 divisor = 1000; 99 divisordeccut = 950; 100 if (flags & HN_B) 101 prefixes = "B\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E"; 102 else 103 prefixes = "\0\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E"; 104 } else { 105 divisor = 1024; 106 divisordeccut = 973; /* ceil(.95 * 1024) */ 107 if (flags & HN_B) 108 prefixes = "B\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E"; 109 else 110 prefixes = "\0\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E"; 111 } 112 } 113 114 #define SCALE2PREFIX(scale) (&prefixes[(scale) * 3]) 115 116 if (quotient < 0) { 117 sign = -1; 118 quotient = -quotient; 119 baselen += 2; /* sign, digit */ 120 } else { 121 sign = 1; 122 baselen += 1; /* digit */ 123 } 124 if (flags & HN_NOSPACE) 125 sep = ""; 126 else { 127 sep = " "; 128 baselen++; 129 } 130 baselen += strlen(suffix); 131 132 /* Check if enough room for `x y' + suffix + `\0' */ 133 if (len < baselen + 1) 134 return (-1); 135 136 if (scale & (HN_AUTOSCALE | HN_GETSCALE)) { 137 /* See if there is additional columns can be used. */ 138 for (max = 1, i = len - baselen; i-- > 0;) 139 max *= 10; 140 141 /* 142 * Divide the number until it fits the given column. 143 * If there will be an overflow by the rounding below, 144 * divide once more. 145 */ 146 for (i = 0; 147 (quotient >= max || (quotient == max - 1 && 148 (remainder >= divisordeccut || remainder >= 149 divisor / 2))) && i < maxscale; i++) { 150 remainder = quotient % divisor; 151 quotient /= divisor; 152 } 153 154 if (scale & HN_GETSCALE) 155 return (i); 156 } else { 157 for (i = 0; i < scale && i < maxscale; i++) { 158 remainder = quotient % divisor; 159 quotient /= divisor; 160 } 161 } 162 163 /* If a value <= 9.9 after rounding and ... */ 164 /* 165 * XXX - should we make sure there is enough space for the decimal 166 * place and if not, don't do HN_DECIMAL? 167 */ 168 if (((quotient == 9 && remainder < divisordeccut) || quotient < 9) && 169 i > 0 && flags & HN_DECIMAL) { 170 s1 = (int)quotient + ((remainder * 10 + divisor / 2) / 171 divisor / 10); 172 s2 = ((remainder * 10 + divisor / 2) / divisor) % 10; 173 r = snprintf(buf, len, "%d%s%d%s%s%s", 174 sign * s1, localeconv()->decimal_point, s2, 175 sep, SCALE2PREFIX(i), suffix); 176 } else 177 r = snprintf(buf, len, "%" PRId64 "%s%s%s", 178 sign * (quotient + (remainder + divisor / 2) / divisor), 179 sep, SCALE2PREFIX(i), suffix); 180 181 return (r); 182 } 183