1                 : /*
       2                 :  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.  
       3                 :  * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
       4                 :  *
       5                 :  * This file is part of the device-mapper userspace tools.
       6                 :  *
       7                 :  * This copyrighted material is made available to anyone wishing to use,
       8                 :  * modify, copy, or redistribute it subject to the terms and conditions
       9                 :  * of the GNU Lesser General Public License v.2.1.
      10                 :  *
      11                 :  * You should have received a copy of the GNU Lesser General Public License
      12                 :  * along with this program; if not, write to the Free Software Foundation,
      13                 :  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      14                 :  */
      15                 : 
      16                 : #include "dmlib.h"
      17                 : 
      18                 : /* FIXME: calculate this. */
      19                 : #define INT_SHIFT 5
      20                 : 
      21           31195 : dm_bitset_t dm_bitset_create(struct dm_pool *mem, unsigned num_bits)
      22                 : {
      23           31195 :         unsigned n = (num_bits / DM_BITS_PER_INT) + 2;
      24           31195 :         size_t size = sizeof(int) * n;
      25                 :         dm_bitset_t bs;
      26                 :         
      27           31195 :         if (mem)
      28           31195 :                 bs = dm_pool_zalloc(mem, size);
      29                 :         else
      30               0 :                 bs = dm_malloc(size);
      31                 : 
      32           31195 :         if (!bs)
      33               0 :                 return NULL;
      34                 : 
      35           31195 :         *bs = num_bits;
      36                 : 
      37           31195 :         if (!mem)
      38               0 :                 dm_bit_clear_all(bs);
      39                 : 
      40           31195 :         return bs;
      41                 : }
      42                 : 
      43               0 : void dm_bitset_destroy(dm_bitset_t bs)
      44                 : {
      45               0 :         dm_free(bs);
      46               0 : }
      47                 : 
      48        53004477 : void dm_bit_union(dm_bitset_t out, dm_bitset_t in1, dm_bitset_t in2)
      49                 : {
      50                 :         int i;
      51     12551585337 :         for (i = (in1[0] / DM_BITS_PER_INT) + 1; i; i--)
      52     12498580860 :                 out[i] = in1[i] | in2[i];
      53        53004477 : }
      54                 : 
      55                 : /*
      56                 :  * FIXME: slow
      57                 :  */
      58       136653312 : static inline int _test_word(uint32_t test, int bit)
      59                 : {
      60      1499888640 :         while (bit < (int) DM_BITS_PER_INT) {
      61      1334771712 :                 if (test & (0x1 << bit))
      62       108189696 :                         return bit;
      63      1226582016 :                 bit++;
      64                 :         }
      65                 : 
      66        28463616 :         return -1;
      67                 : }
      68                 : 
      69       108378624 : int dm_bit_get_next(dm_bitset_t bs, int last_bit)
      70                 : {
      71                 :         int bit, word;
      72                 :         uint32_t test;
      73                 : 
      74       108378624 :         last_bit++;             /* otherwise we'll return the same bit again */
      75                 : 
      76                 :         /*
      77                 :          * bs[0] holds number of bits
      78                 :          */
      79       245220864 :         while (last_bit < (int) bs[0]) {
      80       136653312 :                 word = last_bit >> INT_SHIFT;
      81       136653312 :                 test = bs[word + 1];
      82       136653312 :                 bit = last_bit & (DM_BITS_PER_INT - 1);
      83                 : 
      84       136653312 :                 if ((bit = _test_word(test, bit)) >= 0)
      85       108189696 :                         return (word * DM_BITS_PER_INT) + bit;
      86                 : 
      87        28463616 :                 last_bit = last_bit - (last_bit & (DM_BITS_PER_INT - 1)) +
      88                 :                     DM_BITS_PER_INT;
      89                 :         }
      90                 : 
      91          188928 :         return -1;
      92                 : }
      93                 : 
      94          188928 : int dm_bit_get_first(dm_bitset_t bs)
      95                 : {
      96          188928 :         return dm_bit_get_next(bs, -1);
      97                 : }