lib/libutil/humanize_number.c

   1 /*      $NetBSD: humanize_number.c,v 1.8 2004/07/27 01:56:24 enami Exp $        */
   2 /* $DragonFly: src/lib/libutil/humanize_number.c,v 1.2 2005/03/04 05:31:11 cpressey Exp $ */
   3
   4 /*
   5  * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
   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  * 3. All advertising materials mentioning features or use of this software
  21  *    must display the following acknowledgement:
  22  *      This product includes software developed by the NetBSD
  23  *      Foundation, Inc. and its contributors.
  24  * 4. Neither the name of The NetBSD Foundation nor the names of its
  25  *    contributors may be used to endorse or promote products derived
  26  *    from this software without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  29  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  30  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  31  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  32  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  35  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  36  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  38  * POSSIBILITY OF SUCH DAMAGE.
  39  *
  40  * $FreeBSD: /repoman/r/ncvs/src/lib/libutil/humanize_number.c,v 1.1.2.1 2004/09/28 18:24:10 pjd Exp $
  41  */
  42
  43 #include <sys/cdefs.h>
  44 #include <sys/types.h>
  45
  46 #include <assert.h>
  47 #include <locale.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51
  52 #include "libutil.h"
  53
  54 int
  55 humanize_number(char *buf, size_t len, int64_t bytes,
  56     const char *suffix, int scale, int flags)
  57 {
  58         const char *prefixes, *sep;
  59         int     b, i, r, maxscale, s1, s2, sign;
  60         int64_t divisor, max;
  61         size_t  baselen;
  62
  63         assert(buf != NULL);
  64         assert(suffix != NULL);
  65         assert(scale >= 0);
  66
  67         if (flags & HN_DIVISOR_1000) {
  68                 /* SI for decimal multiplies */
  69                 divisor = 1000;
  70                 if (flags & HN_B)
  71                         prefixes = "B\0k\0M\0G\0T\0P\0E";
  72                 else
  73                         prefixes = "\0\0k\0M\0G\0T\0P\0E";
  74         } else {
  75                 /*
  76                  * binary multiplies
  77                  * XXX IEC 60027-2 recommends Ki, Mi, Gi...
  78                  */
  79                 divisor = 1024;
  80                 if (flags & HN_B)
  81                         prefixes = "B\0K\0M\0G\0T\0P\0E";
  82                 else
  83                         prefixes = "\0\0K\0M\0G\0T\0P\0E";
  84         }
  85
  86 #define SCALE2PREFIX(scale)     (&prefixes[(scale) << 1])
  87         maxscale = 7;
  88
  89         if (scale >= maxscale &&
  90             (scale & (HN_AUTOSCALE | HN_GETSCALE)) == 0)
  91                 return (-1);
  92
  93         if (buf == NULL || suffix == NULL)
  94                 return (-1);
  95
  96         if (len > 0)
  97                 buf[0] = '\0';
  98         if (bytes < 0) {
  99                 sign = -1;
 100                 bytes *= -100;
 101                 baselen = 3;            /* sign, digit, prefix */
 102         } else {
 103                 sign = 1;
 104                 bytes *= 100;
 105                 baselen = 2;            /* digit, prefix */
 106         }
 107         if (flags & HN_NOSPACE)
 108                 sep = "";
 109         else {
 110                 sep = " ";
 111                 baselen++;
 112         }
 113         baselen += strlen(suffix);
 114
 115         /* Check if enough room for `x y' + suffix + `\0' */
 116         if (len < baselen + 1)
 117                 return (-1);
 118
 119         if (scale & (HN_AUTOSCALE | HN_GETSCALE)) {
 120                 /* See if there is additional columns can be used. */
 121                 for (max = 100, i = len - baselen; i-- > 0;)
 122                         max *= 10;
 123
 124                 for (i = 0; bytes >= max && i < maxscale; i++)
 125                         bytes /= divisor;
 126
 127                 if (scale & HN_GETSCALE)
 128                         return (i);
 129         } else
 130                 for (i = 0; i < scale && i < maxscale; i++)
 131                         bytes /= divisor;
 132
 133         /* If a value <= 9.9 after rounding and ... */
 134         if (bytes < 995 && i > 0 && flags & HN_DECIMAL) {
 135                 /* baselen + \0 + .N */
 136                 if (len < baselen + 1 + 2)
 137                         return (-1);
 138                 b = ((int)bytes + 5) / 10;
 139                 s1 = b / 10;
 140                 s2 = b % 10;
 141                 r = snprintf(buf, len, "%d%s%d%s%s%s",
 142                     sign * s1, localeconv()->decimal_point, s2,
 143                     sep, SCALE2PREFIX(i), suffix);
 144         } else
 145                 r = snprintf(buf, len, "%lld%s%s%s",
 146                     /* LONGLONG */
 147                     (long long)(sign * ((bytes + 50) / 100)),
 148                     sep, SCALE2PREFIX(i), suffix);
 149
 150         return (r);
 151 }