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/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*
* This file is part of the device-mapper userspace tools.
*
* 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 Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "dmlib.h"
/* FIXME: calculate this. */
#define INT_SHIFT 5
dm_bitset_t dm_bitset_create(struct dm_pool *mem, unsigned num_bits)
{
unsigned n = (num_bits / DM_BITS_PER_INT) + 2;
size_t size = sizeof(int) * n;
dm_bitset_t bs;
if (mem)
bs = dm_pool_zalloc(mem, size);
else
bs = dm_zalloc(size);
if (!bs)
return NULL;
*bs = num_bits;
return bs;
}
void dm_bitset_destroy(dm_bitset_t bs)
{
dm_free(bs);
}
int dm_bitset_equal(dm_bitset_t in1, dm_bitset_t in2)
{
int i;
for (i = (in1[0] / DM_BITS_PER_INT) + 1; i; i--)
if (in1[i] != in2[i])
return 0;
return 1;
}
void dm_bit_and(dm_bitset_t out, dm_bitset_t in1, dm_bitset_t in2)
{
int i;
for (i = (in1[0] / DM_BITS_PER_INT) + 1; i; i--)
out[i] = in1[i] & in2[i];
}
void dm_bit_union(dm_bitset_t out, dm_bitset_t in1, dm_bitset_t in2)
{
int i;
for (i = (in1[0] / DM_BITS_PER_INT) + 1; i; i--)
out[i] = in1[i] | in2[i];
}
static int _test_word(uint32_t test, int bit)
{
uint32_t tb = test >> bit;
return (tb ? ffs(tb) + bit - 1 : -1);
}
int dm_bit_get_next(dm_bitset_t bs, int last_bit)
{
int bit, word;
uint32_t test;
last_bit++; /* otherwise we'll return the same bit again */
/*
* bs[0] holds number of bits
*/
while (last_bit < (int) bs[0]) {
word = last_bit >> INT_SHIFT;
test = bs[word + 1];
bit = last_bit & (DM_BITS_PER_INT - 1);
if ((bit = _test_word(test, bit)) >= 0)
return (word * DM_BITS_PER_INT) + bit;
last_bit = last_bit - (last_bit & (DM_BITS_PER_INT - 1)) +
DM_BITS_PER_INT;
}
return -1;
}
int dm_bit_get_first(dm_bitset_t bs)
{
return dm_bit_get_next(bs, -1);
}
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