diff --git a/include/ntfs/bitmap.h b/include/ntfs/bitmap.h index e69de29b..3f2694b2 100644 --- a/include/ntfs/bitmap.h +++ b/include/ntfs/bitmap.h @@ -0,0 +1,107 @@ +/* + * bitmap.h - Exports for bitmap handling. Part of the Linux-NTFS project. + * + * Copyright (c) 2000-2003 Anton Altaparmakov + * + * This program/include file 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; either version 2 of the License, or + * (at your option) any later version. + * + * This program/include file is distributed in the hope that it will 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 (in the main directory of the Linux-NTFS + * distribution in the file COPYING); if not, write to the Free Software + * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef _NTFS_BITMAP_H +#define _NTFS_BITMAP_H + +#include "types.h" +#include "attrib.h" + +/* + * NOTES: + * + * - Operations are 8-bit only to ensure the functions work both on little + * and big endian machines! So don't make them 32-bit ops! + * - bitmap starts at bit = 0 and ends at bit = bitmap size - 1. + * - _Caller_ has to make sure that the bit to operate on is less than the + * size of the bitmap. + */ + +/** + * ntfs_bit_set - set a bit in a field of bits + * @bitmap: field of bits + * @bit: bit to set + * @new_value: value to set bit to (0 or 1) + * + * Set the bit @bit in the @bitmap to @new_value. Ignore all errors. + */ +static __inline__ void ntfs_bit_set(u8 *bitmap, const u64 bit, + const u8 new_value) +{ +// Dprintf("bitmap %p, bit 0x%llx, new_value %i\n", bitmap, bit, new_value); + if (!bitmap || new_value > 1) + return; + if (!new_value) + bitmap[bit >> 3] &= ~(1 << (bit & 7)); + else + bitmap[bit >> 3] |= (1 << (bit & 7)); +} + +/** + * ntfs_bit_get - get value of a bit in a field of bits + * @bitmap: field of bits + * @bit: bit to get + * + * Get and return the value of the bit @bit in @bitmap (0 or 1). + * Return -1 on error. + */ +static __inline__ char ntfs_bit_get(const u8 *bitmap, const u64 bit) +{ + if (!bitmap) + return -1; + return (bitmap[bit >> 3] >> (bit & 7)) & 1; +} + +static __inline__ void ntfs_bit_change(u8 *bitmap, const u64 bit) +{ + if (!bitmap) + return; + bitmap[bit >> 3] ^= 1 << (bit & 7); +} + +/** + * ntfs_bit_get_and_set - get value of a bit in a field of bits and set it + * @bitmap: field of bits + * @bit: bit to get/set + * @new_value: value to set bit to (0 or 1) + * + * Return the value of the bit @bit and set it to @new_value (0 or 1). + * Return -1 on error. + */ +static __inline__ char ntfs_bit_get_and_set(u8 *bitmap, const u64 bit, + const u8 new_value) +{ + register u8 old_bit, shift; + + if (!bitmap || new_value > 1) + return -1; + shift = bit & 7; + old_bit = (bitmap[bit >> 3] >> shift) & 1; + if (new_value != old_bit) + bitmap[bit >> 3] ^= 1 << shift; + return old_bit; +} + +extern int ntfs_bitmap_set_run(ntfs_attr *na, s64 start_bit, s64 count); +extern int ntfs_bitmap_clear_run(ntfs_attr *na, s64 start_bit, s64 count); + +#endif /* defined _NTFS_BITMAP_H */ +