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/*
* Copyright (c) 2003, Trent Nelson, <trent@arpa.com>.
* All rights reserved.
*
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <unistd.h>
#include "convtbl.h"
struct convtbl convtbl[] = {
/* mul, scale, str */
[SC_BYTE] = { BYTE, BYTES, "bytes" },
[SC_KILOBYTE] = { BYTE, KILO, "KB" },
[SC_MEGABYTE] = { BYTE, MEGA, "MB" },
[SC_GIGABYTE] = { BYTE, GIGA, "GB" },
[SC_BIT] = { BIT, BITS, "b" },
[SC_KILOBIT] = { BIT, KILO, "Kb" },
[SC_MEGABIT] = { BIT, MEGA, "Mb" },
[SC_GIGABIT] = { BIT, GIGA, "Gb" },
[SC_AUTO] = { 0, 0, "" }
};
static
struct convtbl *
get_tbl_ptr(const u_long size, const u_int scale)
{
u_long tmp;
u_int idx;
/* If our index is out of range, default to auto-scaling. */
idx = scale < SC_AUTO ? scale : SC_AUTO;
if (idx == SC_AUTO)
/*
* Simple but elegant algorithm. Count how many times
* we can shift our size value right by a factor of ten,
* incrementing an index each time. We then use the
* index as the array index into the conversion table.
*/
for (tmp = size, idx = SC_KILOBYTE;
tmp >= MEGA && idx < SC_GIGABYTE;
tmp >>= 10, idx++);
return (&convtbl[idx]);
}
double
convert(const u_long size, const u_int scale)
{
struct convtbl *tp;
tp = get_tbl_ptr(size, scale);
return ((double)size * tp->mul / tp->scale);
}
const char *
get_string(const u_long size, const u_int scale)
{
struct convtbl *tp;
tp = get_tbl_ptr(size, scale);
return (tp->str);
}
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