1 /*
2 * bitmap.h - Exports for bitmap handling. Originated from the Linux-NTFS project.
3 *
4 * Copyright (c) 2000-2004 Anton Altaparmakov
5 * Copyright (c) 2004-2005 Richard Russon
6 *
7 * This program/include file is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as published
9 * by the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program/include file is distributed in the hope that it will be
13 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program (in the main directory of the NTFS-3G
19 * distribution in the file COPYING); if not, write to the Free Software
20 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23 #ifndef _NTFS_BITMAP_H
24 #define _NTFS_BITMAP_H
25
26 #include "types.h"
27 #include "attrib.h"
28
29 /*
30 * NOTES:
31 *
32 * - Operations are 8-bit only to ensure the functions work both on little
33 * and big endian machines! So don't make them 32-bit ops!
34 * - bitmap starts at bit = 0 and ends at bit = bitmap size - 1.
35 * - _Caller_ has to make sure that the bit to operate on is less than the
36 * size of the bitmap.
37 */
38
39 extern void ntfs_bit_set(u8 *bitmap, const u64 bit, const u8 new_value);
40 extern char ntfs_bit_get(const u8 *bitmap, const u64 bit);
41 extern char ntfs_bit_get_and_set(u8 *bitmap, const u64 bit, const u8 new_value);
42 extern int ntfs_bitmap_set_run(ntfs_attr *na, s64 start_bit, s64 count);
43 extern int ntfs_bitmap_clear_run(ntfs_attr *na, s64 start_bit, s64 count);
44
45 /**
46 * ntfs_bitmap_set_bit - set a bit in a bitmap
47 * @na: attribute containing the bitmap
48 * @bit: bit to set
49 *
50 * Set the @bit in the bitmap described by the attribute @na.
51 *
52 * On success return 0 and on error return -1 with errno set to the error code.
53 */
ntfs_bitmap_set_bit(ntfs_attr * na,s64 bit)54 static __inline__ int ntfs_bitmap_set_bit(ntfs_attr *na, s64 bit)
55 {
56 return ntfs_bitmap_set_run(na, bit, 1);
57 }
58
59 /**
60 * ntfs_bitmap_clear_bit - clear a bit in a bitmap
61 * @na: attribute containing the bitmap
62 * @bit: bit to clear
63 *
64 * Clear @bit in the bitmap described by the attribute @na.
65 *
66 * On success return 0 and on error return -1 with errno set to the error code.
67 */
ntfs_bitmap_clear_bit(ntfs_attr * na,s64 bit)68 static __inline__ int ntfs_bitmap_clear_bit(ntfs_attr *na, s64 bit)
69 {
70 return ntfs_bitmap_clear_run(na, bit, 1);
71 }
72
73 /*
74 * rol32 - rotate a 32-bit value left
75 *
76 * @word: value to rotate
77 * @shift: bits to roll
78 */
ntfs_rol32(u32 word,unsigned int shift)79 static __inline__ u32 ntfs_rol32(u32 word, unsigned int shift)
80 {
81 return (word << shift) | (word >> (32 - shift));
82 }
83
84 /*
85 * ror32 - rotate a 32-bit value right
86 *
87 * @word: value to rotate
88 * @shift: bits to roll
89 */
ntfs_ror32(u32 word,unsigned int shift)90 static __inline__ u32 ntfs_ror32(u32 word, unsigned int shift)
91 {
92 return (word >> shift) | (word << (32 - shift));
93 }
94
95 #endif /* defined _NTFS_BITMAP_H */
96
97