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Add new function ntfs_bitmap_set_run() to complement the existing 

ntfs_bitmap_clear_run().

(Logical change 1.109)
edge.strict_endians
cantab.net!aia21 2003-01-25 15:26:56 +00:00
parent 6f0025bf50
commit 0bda9e5cda
2 changed files with 62 additions and 16 deletions
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3
include/bitmap.h
View File

@ -1,7 +1,7 @@
/*
* bitmap.h - Exports for bitmap handling. Part of the Linux-NTFS project.
*
* Copyright (c) 2000-2002 Anton Altaparmakov
* 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
@ -100,6 +100,7 @@ static __inline__ char ntfs_bit_get_and_set(u8 *bitmap, const u64 bit,
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 */

75
libntfs/bitmap.c
View File

@ -1,7 +1,7 @@
/*
* bitmap.c - Bitmap handling code. Part of the Linux-NTFS project.
*
* Copyright (c) 2002 Anton Altaparmakov
* Copyright (c) 2002-2003 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
@ -21,6 +21,7 @@
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include "types.h"
@ -29,17 +30,19 @@
/**
* ntfs_bitmap_clear_run - clear a run of bits in a bitmap
* ntfs_bitmap_set_bits_in__run - set a run of bits in a bitmap to a value
* @na: attribute containing the bitmap
* @start_bit: first bit to clear
* @count: number of bits to clear
* @start_bit: first bit to set
* @count: number of bits to set
* @value: value to set the bits to (i.e. 0 or 1)
*
* Clear @count bits starting at bit @start_bit in the bitmap described by the
* attribute @na.
* Set @count bits starting at bit @start_bit in the bitmap described by the
* attribute @na to @value, where @value is either 0 or 1.
*
* On success return 0 and on error return -1 with errno set to the error code.
*/
int ntfs_bitmap_clear_run(ntfs_attr *na, s64 start_bit, s64 count)
static int ntfs_bitmap_set_bits_in_run(ntfs_attr *na, s64 start_bit, s64 count,
int value)
{
u8 *buf, *lastbyte_buf;
s64 bufsize, br;
@ -61,10 +64,12 @@ int ntfs_bitmap_clear_run(ntfs_attr *na, s64 start_bit, s64 count)
if (bufsize > 8192)
bufsize = 8192;
/* Allocate already zeroed memory. */
buf = (u8*)calloc(1, bufsize);
/* Allocate memory. */
buf = (u8*)malloc(bufsize);
if (!buf)
return -1;
/* Depending on @value, zero or set all bits in the allocated buffer. */
memset(buf, value ? 0xff : 0, bufsize);
/* If there is a first partial byte... */
if (bit) {
@ -75,9 +80,13 @@ int ntfs_bitmap_clear_run(ntfs_attr *na, s64 start_bit, s64 count)
errno = EIO;
return -1;
}
/* and clear the appropriate bits in it. */
while ((bit & 7) && count--)
*buf &= ~(1 << bit++);
/* and set or clear the appropriate bits in it. */
while ((bit & 7) && count--) {
if (value)
*buf |= 1 << bit++;
else
*buf &= ~(1 << bit++);
}
/* Update @start_bit to the new position. */
start_bit = (start_bit + 7) & ~7;
}
@ -115,9 +124,13 @@ int ntfs_bitmap_clear_run(ntfs_attr *na, s64 start_bit, s64 count)
err = EIO;
goto free_err_out;
}
/* and clear the appropriate bits in it. */
while (bit && count--)
*lastbyte_buf &= ~(1 << --bit);
/* and set/clear the appropriate bits in it. */
while (bit && count--) {
if (value)
*lastbyte_buf |= 1 << --bit;
else
*lastbyte_buf &= ~(1 << --bit);
}
/* We don't want to come back here... */
bit = 0;
/* We have a last byte that we have handled. */
@ -166,3 +179,35 @@ free_err_out:
return -1;
}
/**
* ntfs_bitmap_set_run - set a run of bits in a bitmap
* @na: attribute containing the bitmap
* @start_bit: first bit to set
* @count: number of bits to set
*
* Set @count bits starting at bit @start_bit in the bitmap described by the
* attribute @na.
*
* On success return 0 and on error return -1 with errno set to the error code.
*/
int ntfs_bitmap_set_run(ntfs_attr *na, s64 start_bit, s64 count)
{
return ntfs_bitmap_set_bits_in_run(na, start_bit, count, 1);
}
/**
* ntfs_bitmap_clear_run - clear a run of bits in a bitmap
* @na: attribute containing the bitmap
* @start_bit: first bit to clear
* @count: number of bits to clear
*
* Clear @count bits starting at bit @start_bit in the bitmap described by the
* attribute @na.
*
* On success return 0 and on error return -1 with errno set to the error code.
*/
int ntfs_bitmap_clear_run(ntfs_attr *na, s64 start_bit, s64 count)
{
return ntfs_bitmap_set_bits_in_run(na, start_bit, count, 0);
}