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 * 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 __FBSDID("$FreeBSD$"); 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 int 46 humanize_number(char *buf, size_t len, int64_t bytes, 47 const char *suffix, int scale, int flags) 48 { 49 const char *prefixes, *sep; 50 int b, i, r, maxscale, s1, s2, sign; 51 int64_t divisor, max; 52 size_t baselen; 53 54 assert(buf != NULL); 55 assert(suffix != NULL); 56 assert(scale >= 0); 57 58 if (flags & HN_DIVISOR_1000) { 59 /* SI for decimal multiplies */ 60 divisor = 1000; 61 if (flags & HN_B) 62 prefixes = "B\0k\0M\0G\0T\0P\0E"; 63 else 64 prefixes = "\0\0k\0M\0G\0T\0P\0E"; 65 } else { 66 /* 67 * binary multiplies 68 * XXX IEC 60027-2 recommends Ki, Mi, Gi... 69 */ 70 divisor = 1024; 71 if (flags & HN_B) 72 prefixes = "B\0K\0M\0G\0T\0P\0E"; 73 else 74 prefixes = "\0\0K\0M\0G\0T\0P\0E"; 75 } 76 77 #define SCALE2PREFIX(scale) (&prefixes[(scale) << 1]) 78 maxscale = 7; 79 80 if (scale >= maxscale && 81 (scale & (HN_AUTOSCALE | HN_GETSCALE)) == 0) 82 return (-1); 83 84 if (buf == NULL || suffix == NULL) 85 return (-1); 86 87 if (len > 0) 88 buf[0] = '\0'; 89 if (bytes < 0) { 90 sign = -1; 91 bytes *= -100; 92 baselen = 3; /* sign, digit, prefix */ 93 } else { 94 sign = 1; 95 bytes *= 100; 96 baselen = 2; /* digit, prefix */ 97 } 98 if (flags & HN_NOSPACE) 99 sep = ""; 100 else { 101 sep = " "; 102 baselen++; 103 } 104 baselen += strlen(suffix); 105 106 /* Check if enough room for `x y' + suffix + `\0' */ 107 if (len < baselen + 1) 108 return (-1); 109 110 if (scale & (HN_AUTOSCALE | HN_GETSCALE)) { 111 /* See if there is additional columns can be used. */ 112 for (max = 100, i = len - baselen; i-- > 0;) 113 max *= 10; 114 115 /* 116 * Divide the number until it fits the given column. 117 * If there will be an overflow by the rounding below, 118 * divide once more. 119 */ 120 for (i = 0; bytes >= max - 50 && i < maxscale; i++) 121 bytes /= divisor; 122 123 if (scale & HN_GETSCALE) 124 return (i); 125 } else 126 for (i = 0; i < scale && i < maxscale; i++) 127 bytes /= divisor; 128 129 /* If a value <= 9.9 after rounding and ... */ 130 if (bytes < 995 && i > 0 && flags & HN_DECIMAL) { 131 /* baselen + \0 + .N */ 132 if (len < baselen + 1 + 2) 133 return (-1); 134 b = ((int)bytes + 5) / 10; 135 s1 = b / 10; 136 s2 = b % 10; 137 r = snprintf(buf, len, "%d%s%d%s%s%s", 138 sign * s1, localeconv()->decimal_point, s2, 139 sep, SCALE2PREFIX(i), suffix); 140 } else 141 r = snprintf(buf, len, "%" PRId64 "%s%s%s", 142 sign * ((bytes + 50) / 100), 143 sep, SCALE2PREFIX(i), suffix); 144 145 return (r); 146 } 147