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/* nbdkit
* Copyright Red Hat
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * 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.
*
* * Neither the name of Red Hat nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RED HAT 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 RED HAT 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 <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <nbdkit-plugin.h>
#include "bitmap.h"
#include "rounding.h"
#include "nextnonzero.h"
int
bitmap_resize (struct bitmap *bm, uint64_t new_size)
{
uint8_t *new_bitmap;
const size_t old_bm_size = bm->size;
uint64_t new_bm_size_u64;
size_t new_bm_size;
new_bm_size_u64 = DIV_ROUND_UP (new_size,
bm->blksize * UINT64_C (8) / bm->bpb);
if (new_bm_size_u64 > SIZE_MAX) {
nbdkit_error ("bitmap too large for this architecture");
return -1;
}
new_bm_size = (size_t) new_bm_size_u64;
if (new_bm_size > 0) {
new_bitmap = realloc (bm->bitmap, new_bm_size);
if (new_bitmap == NULL) {
nbdkit_error ("realloc: %m");
return -1;
}
}
else {
free (bm->bitmap);
new_bitmap = NULL;
}
bm->bitmap = new_bitmap;
bm->size = new_bm_size;
if (old_bm_size < new_bm_size)
memset (&bm->bitmap[old_bm_size], 0, new_bm_size-old_bm_size);
nbdkit_debug ("bitmap resized to %zu bytes", new_bm_size);
return 0;
}
int64_t
bitmap_next (const struct bitmap *bm, uint64_t blk)
{
uint64_t limit = bm->size * bm->ibpb;
const uint8_t *p;
/* Align to the next byte boundary. */
for (; blk < limit && (blk & (bm->ibpb-1)) != 0; ++blk) {
if (bitmap_get_blk (bm, blk, 0) != 0)
return blk;
}
if (blk == limit)
return -1;
/* Now we're at a byte boundary we can use a fast string function to
* find the next non-zero byte.
*/
p = &bm->bitmap[blk >> (3 - bm->bitshift)];
p = (const uint8_t *) next_non_zero ((const char *) p,
&bm->bitmap[bm->size] - p);
if (p == NULL)
return -1;
/* Now check the non-zero byte to find out which bit (ie. block) is set. */
blk = (p - bm->bitmap) << (3 - bm->bitshift);
for (; blk < limit; ++blk) {
if (bitmap_get_blk (bm, blk, 0) != 0)
return blk;
}
/* Should never be reached. */
abort ();
}
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