99 lines
3.0 KiB
C
99 lines
3.0 KiB
C
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/*
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* Copyright (c) 2003, Trent Nelson, <trent@arpa.com>.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/types.h>
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#include <unistd.h>
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#include "convtbl.h"
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struct convtbl convtbl[] = {
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/* mul, scale, str */
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{ BYTE, BYTES, "bytes" }, /* SC_BYTE (0) */
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{ BYTE, KILO, "KB" }, /* SC_KILOBYTE (1) */
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{ BYTE, MEGA, "MB" }, /* SC_MEGABYTE (2) */
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{ BYTE, GIGA, "GB" }, /* SC_GIGABYTE (3) */
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{ BIT, BITS, "b" }, /* SC_BITS (4) */
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{ BIT, KILO, "Kb" }, /* SC_KILOBITS (5) */
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{ BIT, MEGA, "Mb" }, /* SC_MEGABITS (6) */
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{ BIT, GIGA, "Gb" }, /* SC_GIGABITS (7) */
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{ 0, 0, "" } /* SC_AUTO (8) */
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};
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static __inline__
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struct convtbl *
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get_tbl_ptr(const u_long size, const u_int scale)
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{
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struct convtbl *tbl_ptr = NULL;
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u_long tmp = 0;
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u_int index = scale;
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/* If our index is out of range, default to auto-scaling. */
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if (index > SC_AUTO)
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index = SC_AUTO;
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if (index == SC_AUTO)
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/*
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* Simple but elegant algorithm. Count how many times
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* we can shift our size value right by a factor of ten,
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* incrementing an index each time. We then use the
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* index as the array index into the conversion table.
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*/
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for (tmp = size, index = SC_KILOBYTE;
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tmp >= MEGA && index <= SC_GIGABYTE;
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tmp >>= 10, index++);
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tbl_ptr = &convtbl[index];
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return tbl_ptr;
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}
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double
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convert(const u_long size, const u_int scale)
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{
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struct convtbl *tp = NULL;
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tp = get_tbl_ptr(size, scale);
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return ((double)size * tp->mul / tp->scale);
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}
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char *
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get_string(const u_long size, const u_int scale)
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{
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struct convtbl *tp = NULL;
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tp = get_tbl_ptr(size, scale);
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return tp->str;
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}
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