mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-21 11:13:30 +00:00
133 lines
3.0 KiB
C
133 lines
3.0 KiB
C
/*-
|
|
* Copyright (C) 1996
|
|
* David L. Nugent. 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT 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 DAVID L. NUGENT 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.
|
|
*/
|
|
|
|
#ifndef lint
|
|
static const char rcsid[] =
|
|
"$FreeBSD$";
|
|
#endif /* not lint */
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#include "bitmap.h"
|
|
|
|
struct bitmap
|
|
bm_alloc(int size)
|
|
{
|
|
struct bitmap bm;
|
|
int szmap = (size / 8) + !!(size % 8);
|
|
|
|
bm.size = size;
|
|
bm.map = malloc(szmap);
|
|
if (bm.map)
|
|
memset(bm.map, 0, szmap);
|
|
return bm;
|
|
}
|
|
|
|
void
|
|
bm_dealloc(struct bitmap * bm)
|
|
{
|
|
if (bm->map)
|
|
free(bm->map);
|
|
}
|
|
|
|
static void
|
|
bm_getmask(int *pos, unsigned char *bmask)
|
|
{
|
|
*bmask = (unsigned char) (1 << (*pos % 8));
|
|
*pos /= 8;
|
|
}
|
|
|
|
void
|
|
bm_setbit(struct bitmap * bm, int pos)
|
|
{
|
|
unsigned char bmask;
|
|
|
|
bm_getmask(&pos, &bmask);
|
|
bm->map[pos] |= bmask;
|
|
}
|
|
|
|
void
|
|
bm_clrbit(struct bitmap * bm, int pos)
|
|
{
|
|
unsigned char bmask;
|
|
|
|
bm_getmask(&pos, &bmask);
|
|
bm->map[pos] &= ~bmask;
|
|
}
|
|
|
|
int
|
|
bm_isset(struct bitmap * bm, int pos)
|
|
{
|
|
unsigned char bmask;
|
|
|
|
bm_getmask(&pos, &bmask);
|
|
return !!(bm->map[pos] & bmask);
|
|
}
|
|
|
|
int
|
|
bm_firstunset(struct bitmap * bm)
|
|
{
|
|
int szmap = (bm->size / 8) + !!(bm->size % 8);
|
|
int at = 0;
|
|
int pos = 0;
|
|
|
|
while (pos < szmap) {
|
|
unsigned char bmv = bm->map[pos++];
|
|
unsigned char bmask = 1;
|
|
|
|
while (bmask & 0xff) {
|
|
if ((bmv & bmask) == 0)
|
|
return at;
|
|
bmask <<= 1;
|
|
++at;
|
|
}
|
|
}
|
|
return at;
|
|
}
|
|
|
|
int
|
|
bm_lastset(struct bitmap * bm)
|
|
{
|
|
int szmap = (bm->size / 8) + !!(bm->size % 8);
|
|
int at = 0;
|
|
int pos = 0;
|
|
int ofs = 0;
|
|
|
|
while (pos < szmap) {
|
|
unsigned char bmv = bm->map[pos++];
|
|
unsigned char bmask = 1;
|
|
|
|
while (bmask & 0xff) {
|
|
if ((bmv & bmask) != 0)
|
|
ofs = at;
|
|
bmask <<= 1;
|
|
++at;
|
|
}
|
|
}
|
|
return ofs;
|
|
}
|