1 /* $NetBSD: humanize_number.c,v 1.14 2008/04/28 20:22:59 martin Exp $ */ 2 3 /* 4 * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc. 5 * Copyright 2013 John-Mark Gurney <jmg@FreeBSD.org> 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 * 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. 32 * 33 * $FreeBSD: head/lib/libutil/humanize_number.c 256130 2013-10-07 22:22:57Z jmg $ 34 */ 35 36 #include <sys/types.h> 37 #include <assert.h> 38 #include <inttypes.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <locale.h> 43 #include <libutil.h> 44 45 static const int maxscale = 7; 46 47 int 48 humanize_number(char *buf, size_t len, int64_t quotient, 49 const char *suffix, int scale, int flags) 50 { 51 const char *prefixes, *sep; 52 int i, r, remainder, s1, s2, sign; 53 int divisordeccut; 54 int64_t divisor, max; 55 size_t baselen; 56 57 /* Since so many callers don't check -1, NUL terminate the buffer */ 58 if (len > 0) 59 buf[0] = '\0'; 60 61 /* validate args */ 62 if (buf == NULL || suffix == NULL) 63 return (-1); 64 if (scale < 0) 65 return (-1); 66 else if (scale >= maxscale && 67 ((scale & ~(HN_AUTOSCALE|HN_GETSCALE)) != 0)) 68 return (-1); 69 if ((flags & HN_DIVISOR_1000) && (flags & HN_IEC_PREFIXES)) 70 return (-1); 71 72 /* setup parameters */ 73 remainder = 0; 74 75 if (flags & HN_IEC_PREFIXES) { 76 baselen = 2; 77 /* 78 * Use the prefixes for power of two recommended by 79 * the International Electrotechnical Commission 80 * (IEC) in IEC 80000-3 (i.e. Ki, Mi, Gi...). 81 * 82 * HN_IEC_PREFIXES implies a divisor of 1024 here 83 * (use of HN_DIVISOR_1000 would have triggered 84 * an assertion earlier). 85 */ 86 divisor = 1024; 87 divisordeccut = 973; /* ceil(.95 * 1024) */ 88 if (flags & HN_B) 89 prefixes = "B\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei"; 90 else 91 prefixes = "\0\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei"; 92 } else { 93 baselen = 1; 94 if (flags & HN_DIVISOR_1000) { 95 divisor = 1000; 96 divisordeccut = 950; 97 if (flags & HN_B) 98 prefixes = "B\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E"; 99 else 100 prefixes = "\0\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E"; 101 } else { 102 divisor = 1024; 103 divisordeccut = 973; /* ceil(.95 * 1024) */ 104 if (flags & HN_B) 105 prefixes = "B\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E"; 106 else 107 prefixes = "\0\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E"; 108 } 109 } 110 111 #define SCALE2PREFIX(scale) (&prefixes[(scale) * 3]) 112 113 if (quotient < 0) { 114 sign = -1; 115 quotient = -quotient; 116 baselen += 2; /* sign, digit */ 117 } else { 118 sign = 1; 119 baselen += 1; /* digit */ 120 } 121 if (flags & HN_NOSPACE) 122 sep = ""; 123 else { 124 sep = " "; 125 baselen++; 126 } 127 baselen += strlen(suffix); 128 129 /* Check if enough room for `x y' + suffix + `\0' */ 130 if (len < baselen + 1) 131 return (-1); 132 133 if (scale & (HN_AUTOSCALE | HN_GETSCALE)) { 134 /* See if there is additional columns can be used. */ 135 for (max = 1, i = len - baselen; i-- > 0;) 136 max *= 10; 137 138 /* 139 * Divide the number until it fits the given column. 140 * If there will be an overflow by the rounding below, 141 * divide once more. 142 */ 143 for (i = 0; 144 (quotient >= max || (quotient == max - 1 && 145 remainder >= divisordeccut)) && i < maxscale; i++) { 146 remainder = quotient % divisor; 147 quotient /= divisor; 148 } 149 150 if (scale & HN_GETSCALE) 151 return (i); 152 } else { 153 for (i = 0; i < scale && i < maxscale; i++) { 154 remainder = quotient % divisor; 155 quotient /= divisor; 156 } 157 } 158 159 /* 160 * Generate base output 161 */ 162 r = snprintf(buf, len, "%" PRId64 "%s%s%s", 163 sign * (quotient + (remainder + divisor / 2) / divisor), 164 sep, SCALE2PREFIX(i), suffix); 165 166 if ((flags & HN_FRACTIONAL) && (u_int)r + 3 <= len && i) { 167 /* 168 * If FRACTIONAL is specified output up to two fractional 169 * digits, unless the value was not divided out. 170 */ 171 int64_t frac; 172 int n; 173 174 n = (int)len - r - 2; 175 frac = 1; 176 if (n > 2) /* max 2 fractional digits */ 177 n = 2; 178 179 while (n) { 180 frac = frac * 10; 181 --n; 182 } 183 s1 = (int)quotient + ((remainder * frac + divisor / 2) / 184 divisor / frac); 185 s2 = ((remainder * frac + divisor / 2) / divisor) % frac; 186 r = snprintf(buf, len, "%d%s%d%s%s%s", 187 sign * s1, localeconv()->decimal_point, s2, 188 sep, SCALE2PREFIX(i), suffix); 189 } else if ((flags & HN_DECIMAL) && (u_int)r + 3 <= len && 190 (((quotient == 9 && remainder < divisordeccut) || 191 quotient < 9) && i > 0)) { 192 /* 193 * If DECIMAL is specified and the value is <= 9.9 after 194 * rounding, and it fits, add one fractional digit. 195 */ 196 s1 = (int)quotient + ((remainder * 10 + divisor / 2) / 197 divisor / 10); 198 s2 = ((remainder * 10 + divisor / 2) / divisor) % 10; 199 r = snprintf(buf, len, "%d%s%d%s%s%s", 200 sign * s1, localeconv()->decimal_point, s2, 201 sep, SCALE2PREFIX(i), suffix); 202 } 203 return (r); 204 } 205