1 /* $NetBSD: humanize_number.c,v 1.16 2012/03/17 20:01:14 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center, by Luke Mewburn and by Tomas Svensson. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 #if defined(LIBC_SCCS) && !defined(lint) 35 __RCSID("$NetBSD: humanize_number.c,v 1.16 2012/03/17 20:01:14 christos Exp $"); 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include "namespace.h" 39 #include <assert.h> 40 #include <inttypes.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <locale.h> 45 46 int 47 humanize_number(char *buf, size_t len, int64_t bytes, 48 const char *suffix, int scale, int flags) 49 { 50 const char *prefixes, *sep; 51 int b, r, s1, s2, sign; 52 int64_t divisor, max, post = 1; 53 size_t i, baselen, maxscale; 54 55 _DIAGASSERT(buf != NULL); 56 _DIAGASSERT(suffix != NULL); 57 _DIAGASSERT(scale >= 0); 58 59 if (flags & HN_DIVISOR_1000) { 60 /* SI for decimal multiplies */ 61 divisor = 1000; 62 if (flags & HN_B) 63 prefixes = "B\0k\0M\0G\0T\0P\0E"; 64 else 65 prefixes = "\0\0k\0M\0G\0T\0P\0E"; 66 } else { 67 /* 68 * binary multiplies 69 * XXX IEC 60027-2 recommends Ki, Mi, Gi... 70 */ 71 divisor = 1024; 72 if (flags & HN_B) 73 prefixes = "B\0K\0M\0G\0T\0P\0E"; 74 else 75 prefixes = "\0\0K\0M\0G\0T\0P\0E"; 76 } 77 78 #define SCALE2PREFIX(scale) (&prefixes[(scale) << 1]) 79 maxscale = 7; 80 81 if ((size_t)scale >= maxscale && 82 (scale & (HN_AUTOSCALE | HN_GETSCALE)) == 0) 83 return (-1); 84 85 if (buf == NULL || suffix == NULL) 86 return (-1); 87 88 if (len > 0) 89 buf[0] = '\0'; 90 if (bytes < 0) { 91 sign = -1; 92 baselen = 3; /* sign, digit, prefix */ 93 if (-bytes < INT64_MAX / 100) 94 bytes *= -100; 95 else { 96 bytes = -bytes; 97 post = 100; 98 baselen += 2; 99 } 100 } else { 101 sign = 1; 102 baselen = 2; /* digit, prefix */ 103 if (bytes < INT64_MAX / 100) 104 bytes *= 100; 105 else { 106 post = 100; 107 baselen += 2; 108 } 109 } 110 if (flags & HN_NOSPACE) 111 sep = ""; 112 else { 113 sep = " "; 114 baselen++; 115 } 116 baselen += strlen(suffix); 117 118 /* Check if enough room for `x y' + suffix + `\0' */ 119 if (len < baselen + 1) 120 return (-1); 121 122 if (scale & (HN_AUTOSCALE | HN_GETSCALE)) { 123 /* See if there is additional columns can be used. */ 124 for (max = 100, i = len - baselen; i-- > 0;) 125 max *= 10; 126 127 /* 128 * Divide the number until it fits the given column. 129 * If there will be an overflow by the rounding below, 130 * divide once more. 131 */ 132 for (i = 0; bytes >= max - 50 && i < maxscale; i++) 133 bytes /= divisor; 134 135 if (scale & HN_GETSCALE) { 136 _DIAGASSERT(__type_fit(int, i)); 137 return (int)i; 138 } 139 } else 140 for (i = 0; i < (size_t)scale && i < maxscale; i++) 141 bytes /= divisor; 142 bytes *= post; 143 144 /* If a value <= 9.9 after rounding and ... */ 145 if (bytes < 995 && i > 0 && flags & HN_DECIMAL) { 146 /* baselen + \0 + .N */ 147 if (len < baselen + 1 + 2) 148 return (-1); 149 b = ((int)bytes + 5) / 10; 150 s1 = b / 10; 151 s2 = b % 10; 152 r = snprintf(buf, len, "%d%s%d%s%s%s", 153 sign * s1, localeconv()->decimal_point, s2, 154 sep, SCALE2PREFIX(i), suffix); 155 } else 156 r = snprintf(buf, len, "%" PRId64 "%s%s%s", 157 sign * ((bytes + 50) / 100), 158 sep, SCALE2PREFIX(i), suffix); 159 160 return (r); 161 } 162
