blob: 10b5f6c5b47c196d02627a0dcf58d1be33aa0cf0
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 | */ |
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 | */ |
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 | */ |
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 | */ |
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 |