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/*
* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
*
* 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; either version 2 of the
* License, or any later version.
*
* This program 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; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <errno.h>
#include <gpxe/bitmap.h>
/** @file
*
* Bitmaps for multicast downloads
*
*/
/**
* Resize bitmap
*
* @v bitmap Bitmap
* @v new_length New length of bitmap, in bits
* @ret rc Return status code
*/
int bitmap_resize ( struct bitmap *bitmap, unsigned int new_length ) {
unsigned int old_num_blocks;
unsigned int new_num_blocks;
size_t new_size;
bitmap_block_t *new_blocks;
old_num_blocks = BITMAP_INDEX ( bitmap->length + BITMAP_BLKSIZE - 1 );
new_num_blocks = BITMAP_INDEX ( new_length + BITMAP_BLKSIZE - 1 );
if ( old_num_blocks != new_num_blocks ) {
new_size = ( new_num_blocks * sizeof ( bitmap->blocks[0] ) );
new_blocks = realloc ( bitmap->blocks, new_size );
if ( ! new_blocks ) {
DBGC ( bitmap, "Bitmap %p could not resize to %d "
"bits\n", bitmap, new_length );
return -ENOMEM;
}
bitmap->blocks = new_blocks;
}
bitmap->length = new_length;
while ( old_num_blocks < new_num_blocks ) {
bitmap->blocks[old_num_blocks++] = 0;
}
DBGC ( bitmap, "Bitmap %p resized to %d bits\n", bitmap, new_length );
return 0;
}
/**
* Test bit in bitmap
*
* @v bitmap Bitmap
* @v bit Bit index
* @ret is_set Bit is set
*/
int bitmap_test ( struct bitmap *bitmap, unsigned int bit ) {
unsigned int index = BITMAP_INDEX ( bit );
bitmap_block_t mask = BITMAP_MASK ( bit );
if ( bit >= bitmap->length )
return 0;
return ( bitmap->blocks[index] & mask );
}
/**
* Set bit in bitmap
*
* @v bitmap Bitmap
* @v bit Bit index
*/
void bitmap_set ( struct bitmap *bitmap, unsigned int bit ) {
unsigned int index = BITMAP_INDEX ( bit );
bitmap_block_t mask = BITMAP_MASK ( bit );
DBGC ( bitmap, "Bitmap %p setting bit %d\n", bitmap, bit );
/* Update bitmap */
bitmap->blocks[index] |= mask;
/* Update first gap counter */
while ( bitmap_test ( bitmap, bitmap->first_gap ) ) {
bitmap->first_gap++;
}
}
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