Release 4.11 fs/xfs/libxfs/xfs_bit.c
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_log_format.h"
#include "xfs_bit.h"
/*
* XFS bit manipulation routines, used in non-realtime code.
*/
/*
* Return whether bitmap is empty.
* Size is number of words in the bitmap, which is padded to word boundary
* Returns 1 for empty, 0 for non-empty.
*/
int
xfs_bitmap_empty(uint *map, uint size)
{
uint i;
for (i = 0; i < size; i++) {
if (map[i] != 0)
return 0;
}
return 1;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Christoph Hellwig | 21 | 46.67% | 1 | 33.33% |
| Eric Sandeen | 15 | 33.33% | 1 | 33.33% |
| Jia He | 9 | 20.00% | 1 | 33.33% |
| Total | 45 | 100.00% | 3 | 100.00% |
/*
* Count the number of contiguous bits set in the bitmap starting with bit
* start_bit. Size is the size of the bitmap in words.
*/
int
xfs_contig_bits(uint *map, uint size, uint start_bit)
{
uint * p = ((unsigned int *) map) + (start_bit >> BIT_TO_WORD_SHIFT);
uint result = 0;
uint tmp;
size <<= BIT_TO_WORD_SHIFT;
ASSERT(start_bit < size);
size -= start_bit & ~(NBWORD - 1);
start_bit &= (NBWORD - 1);
if (start_bit) {
tmp = *p++;
/* set to one first offset bits prior to start */
tmp |= (~0U >> (NBWORD-start_bit));
if (tmp != ~0U)
goto found;
result += NBWORD;
size -= NBWORD;
}
while (size) {
if ((tmp = *p++) != ~0U)
goto found;
result += NBWORD;
size -= NBWORD;
}
return result - start_bit;
found:
return result + ffz(tmp) - start_bit;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Timothy Shimmin | 122 | 74.85% | 1 | 50.00% |
| Christoph Hellwig | 41 | 25.15% | 1 | 50.00% |
| Total | 163 | 100.00% | 2 | 100.00% |
/*
* This takes the bit number to start looking from and
* returns the next set bit from there. It returns -1
* if there are no more bits set or the start bit is
* beyond the end of the bitmap.
*
* Size is the number of words, not bytes, in the bitmap.
*/
int xfs_next_bit(uint *map, uint size, uint start_bit)
{
uint * p = ((unsigned int *) map) + (start_bit >> BIT_TO_WORD_SHIFT);
uint result = start_bit & ~(NBWORD - 1);
uint tmp;
size <<= BIT_TO_WORD_SHIFT;
if (start_bit >= size)
return -1;
size -= result;
start_bit &= (NBWORD - 1);
if (start_bit) {
tmp = *p++;
/* set to zero first offset bits prior to start */
tmp &= (~0U << start_bit);
if (tmp != 0U)
goto found;
result += NBWORD;
size -= NBWORD;
}
while (size) {
if ((tmp = *p++) != 0U)
goto found;
result += NBWORD;
size -= NBWORD;
}
return -1;
found:
return result + ffs(tmp) - 1;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Christoph Hellwig | 151 | 94.97% | 1 | 50.00% |
| Timothy Shimmin | 8 | 5.03% | 1 | 50.00% |
| Total | 159 | 100.00% | 2 | 100.00% |
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Christoph Hellwig | 216 | 56.69% | 1 | 11.11% |
| Timothy Shimmin | 130 | 34.12% | 1 | 11.11% |
| Eric Sandeen | 16 | 4.20% | 1 | 11.11% |
| Jia He | 9 | 2.36% | 1 | 11.11% |
| Russell Cattelan | 4 | 1.05% | 2 | 22.22% |
| Dave Chinner | 4 | 1.05% | 2 | 22.22% |
| Nathan Scott | 2 | 0.52% | 1 | 11.11% |
| Total | 381 | 100.00% | 9 | 100.00% |
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