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Diffstat (limited to 'lib/libutil/humanize_number.c')
| -rw-r--r-- | lib/libutil/humanize_number.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/lib/libutil/humanize_number.c b/lib/libutil/humanize_number.c new file mode 100644 index 0000000..b773422 --- /dev/null +++ b/lib/libutil/humanize_number.c @@ -0,0 +1,179 @@ +/* $NetBSD: humanize_number.c,v 1.14 2008/04/28 20:22:59 martin Exp $ */ + +/* + * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc. + * Copyright 2013 John-Mark Gurney <jmg@FreeBSD.org> + * All rights reserved. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, + * NASA Ames Research Center, by Luke Mewburn and by Tomas Svensson. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <assert.h> +#include <inttypes.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <locale.h> +#include <libutil.h> + +static const int maxscale = 7; + +int +humanize_number(char *buf, size_t len, int64_t quotient, + const char *suffix, int scale, int flags) +{ + const char *prefixes, *sep; + int i, r, remainder, s1, s2, sign; + int divisordeccut; + int64_t divisor, max; + size_t baselen; + + /* Since so many callers don't check -1, NUL terminate the buffer */ + if (len > 0) + buf[0] = '\0'; + + /* validate args */ + if (buf == NULL || suffix == NULL) + return (-1); + if (scale < 0) + return (-1); + else if (scale >= maxscale && + ((scale & ~(HN_AUTOSCALE|HN_GETSCALE)) != 0)) + return (-1); + if ((flags & HN_DIVISOR_1000) && (flags & HN_IEC_PREFIXES)) + return (-1); + + /* setup parameters */ + remainder = 0; + + if (flags & HN_IEC_PREFIXES) { + baselen = 2; + /* + * Use the prefixes for power of two recommended by + * the International Electrotechnical Commission + * (IEC) in IEC 80000-3 (i.e. Ki, Mi, Gi...). + * + * HN_IEC_PREFIXES implies a divisor of 1024 here + * (use of HN_DIVISOR_1000 would have triggered + * an assertion earlier). + */ + divisor = 1024; + divisordeccut = 973; /* ceil(.95 * 1024) */ + if (flags & HN_B) + prefixes = "B\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei"; + else + prefixes = "\0\0\0Ki\0Mi\0Gi\0Ti\0Pi\0Ei"; + } else { + baselen = 1; + if (flags & HN_DIVISOR_1000) { + divisor = 1000; + divisordeccut = 950; + if (flags & HN_B) + prefixes = "B\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E"; + else + prefixes = "\0\0\0k\0\0M\0\0G\0\0T\0\0P\0\0E"; + } else { + divisor = 1024; + divisordeccut = 973; /* ceil(.95 * 1024) */ + if (flags & HN_B) + prefixes = "B\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E"; + else + prefixes = "\0\0\0K\0\0M\0\0G\0\0T\0\0P\0\0E"; + } + } + +#define SCALE2PREFIX(scale) (&prefixes[(scale) * 3]) + + if (quotient < 0) { + sign = -1; + quotient = -quotient; + baselen += 2; /* sign, digit */ + } else { + sign = 1; + baselen += 1; /* digit */ + } + if (flags & HN_NOSPACE) + sep = ""; + else { + sep = " "; + baselen++; + } + baselen += strlen(suffix); + + /* Check if enough room for `x y' + suffix + `\0' */ + if (len < baselen + 1) + return (-1); + + if (scale & (HN_AUTOSCALE | HN_GETSCALE)) { + /* See if there is additional columns can be used. */ + for (max = 1, i = len - baselen; i-- > 0;) + max *= 10; + + /* + * Divide the number until it fits the given column. + * If there will be an overflow by the rounding below, + * divide once more. + */ + for (i = 0; + (quotient >= max || (quotient == max - 1 && + remainder >= divisordeccut)) && i < maxscale; i++) { + remainder = quotient % divisor; + quotient /= divisor; + } + + if (scale & HN_GETSCALE) + return (i); + } else { + for (i = 0; i < scale && i < maxscale; i++) { + remainder = quotient % divisor; + quotient /= divisor; + } + } + + /* If a value <= 9.9 after rounding and ... */ + /* + * XXX - should we make sure there is enough space for the decimal + * place and if not, don't do HN_DECIMAL? + */ + if (((quotient == 9 && remainder < divisordeccut) || quotient < 9) && + i > 0 && flags & HN_DECIMAL) { + s1 = (int)quotient + ((remainder * 10 + divisor / 2) / + divisor / 10); + s2 = ((remainder * 10 + divisor / 2) / divisor) % 10; + r = snprintf(buf, len, "%d%s%d%s%s%s", + sign * s1, localeconv()->decimal_point, s2, + sep, SCALE2PREFIX(i), suffix); + } else + r = snprintf(buf, len, "%" PRId64 "%s%s%s", + sign * (quotient + (remainder + divisor / 2) / divisor), + sep, SCALE2PREFIX(i), suffix); + + return (r); +} |
