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 /* validate args */ 58 if (buf == NULL) 59 return (-1); 60 if (scale < 0) 61 return (-1); 62 else if (scale >= maxscale && 63 ((scale & ~(HN_AUTOSCALE|HN_GETSCALE)) != 0)) 64 return (-1); 65 if ((flags & HN_DIVISOR_1000) && (flags & HN_IEC_PREFIXES)) 66 return (-1); 67 68 /* Since so many callers don't check -1, NUL terminate the buffer */ 69 if (len > 0) 70 buf[0] = '\0'; 71 72 if (suffix == NULL) 73 suffix = ""; 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)) && i < maxscale; i++) { 149 remainder = quotient % divisor; 150 quotient /= divisor; 151 } 152 153 if (scale & HN_GETSCALE) 154 return (i); 155 } else { 156 for (i = 0; i < scale && i < maxscale; i++) { 157 remainder = quotient % divisor; 158 quotient /= divisor; 159 } 160 } 161 162 /* 163 * Generate base output 164 */ 165 r = snprintf(buf, len, "%" PRId64 "%s%s%s", 166 sign * (quotient + (remainder + divisor / 2) / divisor), 167 sep, SCALE2PREFIX(i), suffix); 168 169 if ((flags & HN_FRACTIONAL) && (u_int)r + 3 <= len && i) { 170 /* 171 * If FRACTIONAL is specified output up to two fractional 172 * digits, unless the value was not divided out. 173 */ 174 int64_t frac; 175 int n; 176 177 n = (int)len - r - 2; 178 frac = 1; 179 if (n > 2) /* max 2 fractional digits */ 180 n = 2; 181 182 while (n) { 183 frac = frac * 10; 184 --n; 185 } 186 s1 = (int)quotient + ((remainder * frac + divisor / 2) / 187 divisor / frac); 188 s2 = ((remainder * frac + divisor / 2) / divisor) % frac; 189 r = snprintf(buf, len, "%d%s%d%s%s%s", 190 sign * s1, localeconv()->decimal_point, s2, 191 sep, SCALE2PREFIX(i), suffix); 192 } else if ((flags & HN_DECIMAL) && (u_int)r + 3 <= len && 193 (((quotient == 9 && remainder < divisordeccut) || 194 quotient < 9) && i > 0)) { 195 /* 196 * If DECIMAL is specified and the value is <= 9.9 after 197 * rounding, and it fits, add one fractional digit. 198 */ 199 s1 = (int)quotient + ((remainder * 10 + divisor / 2) / 200 divisor / 10); 201 s2 = ((remainder * 10 + divisor / 2) / divisor) % 10; 202 r = snprintf(buf, len, "%d%s%d%s%s%s", 203 sign * s1, localeconv()->decimal_point, s2, 204 sep, SCALE2PREFIX(i), suffix); 205 } 206 return (r); 207 } 208