humanize_number.c
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 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 "bsd_compat.h" 37 38 #if !HAVE_HUMANIZE_NUMBER 39 40 #include <sys/types.h> 41 #include <assert.h> 42 #include <inttypes.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <locale.h> 47 48 #include "humanize_number.h" 49 50 static const int maxscale = 6; 51 52 int 53 humanize_number(char *buf, size_t len, int64_t quotient, 54 const char *suffix, int scale, int flags) 55 { 56 const char *prefixes, *sep; 57 int i, r, remainder, s1, s2, sign; 58 int divisordeccut; 59 int64_t divisor, max; 60 size_t baselen; 61 62 /* Since so many callers don't check -1, NUL terminate the buffer */ 63 if (len > 0) 64 buf[0] = '\0'; 65 66 /* validate args */ 67 if (buf == NULL || suffix == NULL) 68 return (-1); 69 if (scale < 0) 70 return (-1); 71 else if (scale > maxscale && 72 ((scale & ~(HN_AUTOSCALE|HN_GETSCALE)) != 0)) 73 return (-1); 74 if ((flags & HN_DIVISOR_1000) && (flags & HN_IEC_PREFIXES)) 75 return (-1); 76 77 /* setup parameters */ 78 remainder = 0; 79 80 if (flags & HN_IEC_PREFIXES) { 81 baselen = 2; 82 /* 83 * Use the prefixes for power of two recommended by 84 * the International Electrotechnical Commission 85 * (IEC) in IEC 80000-3 (i.e. Ki, Mi, Gi...). 86 * 87 * HN_IEC_PREFIXES implies a divisor of 1024 here 88 * (use of HN_DIVISOR_1000 would have triggered 89 * an assertion earlier). 90 */ 91 divisor = 1024; 92 divisordeccut = 973; /* ceil(.95 * 1024) */ 93 if (flags & HN_B) 94 prefixes = "B\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei"; 95 else 96 prefixes = "\0\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei"; 97 } else { 98 baselen = 1; 99 if (flags & HN_DIVISOR_1000) { 100 divisor = 1000; 101 divisordeccut = 950; 102 if (flags & HN_B) 103 prefixes = "B\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E"; 104 else 105 prefixes = "\0\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E"; 106 } else { 107 divisor = 1024; 108 divisordeccut = 973; /* ceil(.95 * 1024) */ 109 if (flags & HN_B) 110 prefixes = "B\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E"; 111 else 112 prefixes = "\0\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E"; 113 } 114 } 115 116 #define SCALE2PREFIX(scale) (&prefixes[(scale) * 3]) 117 118 if (quotient < 0) { 119 sign = -1; 120 quotient = -quotient; 121 baselen += 2; /* sign, digit */ 122 } else { 123 sign = 1; 124 baselen += 1; /* digit */ 125 } 126 if (flags & HN_NOSPACE) 127 sep = ""; 128 else { 129 sep = " "; 130 baselen++; 131 } 132 baselen += strlen(suffix); 133 134 /* Check if enough room for `x y' + suffix + `\0' */ 135 if (len < baselen + 1) 136 return (-1); 137 138 if (scale & (HN_AUTOSCALE | HN_GETSCALE)) { 139 /* See if there is additional columns can be used. */ 140 for (max = 1, i = len - baselen; i-- > 0;) 141 max *= 10; 142 143 /* 144 * Divide the number until it fits the given column. 145 * If there will be an overflow by the rounding below, 146 * divide once more. 147 */ 148 for (i = 0; 149 (quotient >= max || (quotient == max - 1 && 150 (remainder >= divisordeccut || remainder >= 151 divisor / 2))) && i < maxscale; i++) { 152 remainder = quotient % divisor; 153 quotient /= divisor; 154 } 155 156 if (scale & HN_GETSCALE) 157 return (i); 158 } else { 159 for (i = 0; i < scale && i < maxscale; i++) { 160 remainder = quotient % divisor; 161 quotient /= divisor; 162 } 163 } 164 165 /* If a value <= 9.9 after rounding and ... */ 166 /* 167 * XXX - should we make sure there is enough space for the decimal 168 * place and if not, don't do HN_DECIMAL? 169 */ 170 if (((quotient == 9 && remainder < divisordeccut) || quotient < 9) && 171 i > 0 && flags & HN_DECIMAL) { 172 s1 = (int)quotient + ((remainder * 10 + divisor / 2) / 173 divisor / 10); 174 s2 = ((remainder * 10 + divisor / 2) / divisor) % 10; 175 r = snprintf(buf, len, "%d%s%d%s%s%s", 176 sign * s1, localeconv()->decimal_point, s2, 177 sep, SCALE2PREFIX(i), suffix); 178 } else 179 r = snprintf(buf, len, "%" PRId64 "%s%s%s", 180 sign * (quotient + (remainder + divisor / 2) / divisor), 181 sep, SCALE2PREFIX(i), suffix); 182 183 return (r); 184 } 185 #endif