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/* This file is part of indexlib.
* Copyright (C) 2005 Luís Pedro Coelho <[email protected]>
*
* Indexlib is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation and available as file
* GPL_V2 which is distributed along with indexlib.
*
* Indexlib 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., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA
*
* In addition, as a special exception, the copyright holders give
* permission to link the code of this program with any edition of
* the Qt library by Trolltech AS, Norway (or with modified versions
* of Qt that use the same license as Qt), and distribute linked
* combinations including the two. You must obey the GNU General
* Public License in all respects for all of the code used other than
* Qt. If you modify this file, you may extend this exception to
* your version of the file, but you are not obligated to do so. If
* you do not wish to do so, delete this exception statement from
* your version.
*/
#include "bitstream.h"
#include "logfile.h"
#include "format.h"
#include <assert.h>
bitstream::bitstream( unsigned char* data, unsigned size )
:bytes_( data ),
writeable_( true ),
size_( size ),
cur_( 0 ) { }
bitstream::bitstream( const unsigned char* data, unsigned size )
:bytes_( const_cast<unsigned char*>( data ) ),
writeable_( false ),
size_( size ),
cur_( 0 ) { }
bool bit( unsigned v, unsigned idx ) {
return ( v >> idx ) & 1;
}
bitstream& bitstream::operator << ( uint16_t x ) {
for ( unsigned i = 0; i != 16; ++i ) putbit( bit( x, i ) );
return *this;
}
bitstream& bitstream::operator << ( uint32_t x ) {
for ( unsigned i = 0; i != 32; ++i ) putbit( bit( x, i ) );
return *this;
}
bitstream& bitstream::operator >> ( uint16_t& v ) {
v = 0;
for ( int i = 0; i != 16; ++i ) {
v <<= 1;
v |= getbit();
}
return *this;
}
bitstream& bitstream::operator >> ( uint32_t& v ) {
v = 0;
for ( int i = 0; i != 32; ++i ) {
v <<= 1;
v |= getbit();
}
return *this;
}
void bitstream::putback( uint16_t ) {
assert( cur_ >= 16 );
cur_ -= 16;
}
void bitstream::putback( uint32_t ) {
assert( cur_ >= 32 );
cur_ -= 32;
}
bool bitstream::getbit() {
unsigned inbyte = cur_ % 8;
unsigned byte = cur_ / 8;
++cur_;
return ( bytes_[ byte ] >> inbyte ) & 1;
}
void bitstream::putbit( bool value ) {
unsigned inbyte = cur_ % 8;
unsigned byte = cur_ / 8;
assert( byte < size_ );
if ( value ) bytes_[ byte ] |= ( 1 << inbyte );
else bytes_[ byte ] &= ~( 1 << inbyte );
++cur_;
}
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