mirror of https://github.com/ipxe/ipxe.git
107 lines
2.9 KiB
C
107 lines
2.9 KiB
C
/*
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* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*
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* You can also choose to distribute this program under the terms of
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* the Unmodified Binary Distribution Licence (as given in the file
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* COPYING.UBDL), provided that you have satisfied its requirements.
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*/
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FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
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#include <errno.h>
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#include <ipxe/bitmap.h>
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/** @file
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*
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* Bitmaps for multicast downloads
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*
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*/
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/**
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* Resize bitmap
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*
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* @v bitmap Bitmap
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* @v new_length New length of bitmap, in bits
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* @ret rc Return status code
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*/
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int bitmap_resize ( struct bitmap *bitmap, unsigned int new_length ) {
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unsigned int old_num_blocks;
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unsigned int new_num_blocks;
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size_t new_size;
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bitmap_block_t *new_blocks;
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old_num_blocks = BITMAP_INDEX ( bitmap->length + BITMAP_BLKSIZE - 1 );
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new_num_blocks = BITMAP_INDEX ( new_length + BITMAP_BLKSIZE - 1 );
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if ( old_num_blocks != new_num_blocks ) {
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new_size = ( new_num_blocks * sizeof ( bitmap->blocks[0] ) );
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new_blocks = realloc ( bitmap->blocks, new_size );
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if ( ! new_blocks ) {
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DBGC ( bitmap, "Bitmap %p could not resize to %d "
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"bits\n", bitmap, new_length );
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return -ENOMEM;
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}
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bitmap->blocks = new_blocks;
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}
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bitmap->length = new_length;
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while ( old_num_blocks < new_num_blocks ) {
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bitmap->blocks[old_num_blocks++] = 0;
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}
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DBGC ( bitmap, "Bitmap %p resized to %d bits\n", bitmap, new_length );
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return 0;
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}
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/**
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* Test bit in bitmap
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*
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* @v bitmap Bitmap
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* @v bit Bit index
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* @ret is_set Bit is set
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*/
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int bitmap_test ( struct bitmap *bitmap, unsigned int bit ) {
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unsigned int index = BITMAP_INDEX ( bit );
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bitmap_block_t mask = BITMAP_MASK ( bit );
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if ( bit >= bitmap->length )
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return 0;
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return ( ( bitmap->blocks[index] & mask ) != 0 );
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}
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/**
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* Set bit in bitmap
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*
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* @v bitmap Bitmap
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* @v bit Bit index
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*/
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void bitmap_set ( struct bitmap *bitmap, unsigned int bit ) {
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unsigned int index = BITMAP_INDEX ( bit );
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bitmap_block_t mask = BITMAP_MASK ( bit );
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DBGC ( bitmap, "Bitmap %p setting bit %d\n", bitmap, bit );
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/* Update bitmap */
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bitmap->blocks[index] |= mask;
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/* Update first gap counter */
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while ( bitmap_test ( bitmap, bitmap->first_gap ) ) {
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bitmap->first_gap++;
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}
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}
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