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/******************************************************************************
*******************************************************************************
**
** Copyright (C) 2005 Red Hat, Inc. All rights reserved.
**
** This copyrighted material is made available to anyone wishing to use,
** modify, copy, or redistribute it subject to the terms and conditions
** of the GNU General Public License v.2.
**
*******************************************************************************
******************************************************************************/
/* Basic bitmap manipulation */
#include <stdint.h>
#include <stdio.h>
#include <errno.h>
#include "osi_user.h"
#include "bitmap.h"
#include "block_list.h"
#include "fsck_incore.h"
#include "log.h"
#define BITMAP_SIZE(size, cpb) (size / cpb)
#define BITMAP_BYTE_OFFSET(x, map) ((x % map->chunks_per_byte) \
* map->chunksize )
#define BITMAP_MASK(chunksize) ((2 << (chunksize - 1)) - 1)
uint64_t bitmap_size(struct bmap *bmap) {
return bmap->size;
}
int bitmap_create(struct bmap *bmap, uint64_t size, uint8_t chunksize)
{
if((((chunksize >> 1) << 1) != chunksize) && chunksize != 1) {
log_err("chunksize must be a power of 2\n");
return -1;
}
if(chunksize > 8) {
log_err("chunksize must be <= 8\n");
return -1;
}
bmap->chunksize = chunksize;
bmap->chunks_per_byte = 8 / chunksize;
bmap->size = size;
/* Have to add 1 to BITMAP_SIZE since it's 0-based and mallocs
* must be 1-based */
bmap->mapsize = BITMAP_SIZE(size, bmap->chunks_per_byte)+1;
if(!(bmap->map = malloc(sizeof(char) * bmap->mapsize))) {
log_err("Unable to allocate bitmap of size %"PRIu64"\n",
bmap->mapsize);
return -ENOMEM;
}
if(!memset(bmap->map, 0, sizeof(char) * bmap->mapsize)) {
log_err("Unable to zero bitmap of size %"PRIu64"\n",
bmap->mapsize);
free(bmap->map);
bmap->map = NULL;
return -ENOMEM;
}
log_debug("Allocated bitmap of size %"PRIu64
" with %d chunks per byte\n",
bmap->mapsize, bmap->chunks_per_byte);
return 0;
}
int bitmap_set(struct bmap *bmap, uint64_t offset, uint8_t val)
{
char *byte = NULL;
uint64_t b = offset;
if(offset < bmap->size) {
byte = bmap->map + BITMAP_SIZE(offset, bmap->chunks_per_byte);
b = BITMAP_BYTE_OFFSET(offset, bmap);
*byte |= (val & BITMAP_MASK(bmap->chunksize)) << b;
return 0;
}
log_debug("offset %d out of bounds\n", offset);
return -1;
}
int bitmap_get(struct bmap *bmap, uint64_t bit, uint8_t *val)
{
char *byte = NULL;
uint64_t b = bit;
if(bit < bmap->size) {
byte = bmap->map + BITMAP_SIZE(bit, bmap->chunks_per_byte);
b = BITMAP_BYTE_OFFSET(bit, bmap);
*val = (*byte & (BITMAP_MASK(bmap->chunksize) << b )) >> b;
return 0;
}
log_debug("offset %d out of bounds\n", bit);
return -1;
}
int bitmap_clear(struct bmap *bmap, uint64_t offset)
{
char *byte = NULL;
uint64_t b = offset;
if(offset < bmap->size) {
byte = bmap->map + BITMAP_SIZE(offset, bmap->chunks_per_byte);
b = BITMAP_BYTE_OFFSET(offset, bmap);
*byte &= ~(BITMAP_MASK(bmap->chunksize) << b);
return 0;
}
log_debug("offset %d out of bounds\n", offset);
return -1;
}
void bitmap_destroy(struct bmap *bmap)
{
if(bmap->map)
free(bmap->map);
bmap->size = 0;
bmap->mapsize = 0;
bmap->chunksize = 0;
bmap->chunks_per_byte = 0;
}

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