Merging upstream version 1.0.
Signed-off-by: Daniel Baumann <daniel@debian.org>
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FBB4F0E80A80222F
14 changed files with 508 additions and 366 deletions
88
decoder.h
88
decoder.h
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@ -25,22 +25,33 @@
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Public License.
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*/
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class Input_buffer : public Circular_buffer
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class Range_decoder : public Circular_buffer
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{
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enum { min_available_bytes = 8 };
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long long member_pos;
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uint32_t code;
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uint32_t range;
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bool reload_pending;
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bool at_stream_end_;
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public:
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Input_buffer()
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Range_decoder()
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:
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Circular_buffer( 65536 + min_available_bytes ),
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member_pos( 0 ),
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code( 0 ),
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range( 0xFFFFFFFFU ),
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reload_pending( false ),
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at_stream_end_( false ) {}
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bool at_stream_end() const throw() { return at_stream_end_; }
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int available_bytes() const throw() { return used_bytes(); }
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bool code_is_zero() const throw() { return ( code == 0 ); }
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void finish() throw() { at_stream_end_ = true; }
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bool finished() const throw() { return at_stream_end_ && !used_bytes(); }
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int free_bytes() const throw()
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{ if( at_stream_end_ ) return 0; return Circular_buffer::free_bytes(); }
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long long member_position() const throw() { return member_pos; }
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void purge() throw() { at_stream_end_ = true; Circular_buffer::reset(); }
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void reset() throw() { at_stream_end_ = false; Circular_buffer::reset(); }
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@ -58,39 +69,11 @@ public:
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if( at_stream_end_ || in_size <= 0 ) return 0;
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return Circular_buffer::write_data( in_buffer, in_size );
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}
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};
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class Range_decoder
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{
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mutable long long member_pos;
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uint32_t code;
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uint32_t range;
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bool reload_pending;
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Input_buffer & ibuf;
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public:
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Range_decoder( const int header_size, Input_buffer & buf )
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:
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member_pos( header_size ),
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code( 0 ),
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range( 0xFFFFFFFF ),
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reload_pending( false ),
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ibuf( buf )
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{ for( int i = 0; i < 5; ++i ) code = (code << 8) | get_byte(); }
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bool at_stream_end() const throw() { return ibuf.at_stream_end(); }
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int available_bytes() const throw() { return ibuf.used_bytes(); }
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bool code_is_zero() const throw() { return ( code == 0 ); }
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bool enough_available_bytes() const throw()
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{ return ibuf.enough_available_bytes(); }
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bool finished() const throw() { return ibuf.finished(); }
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long long member_position() const throw() { return member_pos; }
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uint8_t get_byte() const
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uint8_t get_byte()
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{
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++member_pos;
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return ibuf.get_byte();
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return Circular_buffer::get_byte();
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}
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bool try_reload( const bool force = false ) throw()
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@ -100,7 +83,7 @@ public:
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{
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reload_pending = false;
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code = 0;
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range = 0xFFFFFFFF;
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range = 0xFFFFFFFFU;
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for( int i = 0; i < 5; ++i ) code = (code << 8) | get_byte();
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}
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return !reload_pending;
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@ -108,7 +91,7 @@ public:
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void normalize()
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{
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if( range <= 0x00FFFFFF )
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if( range <= 0x00FFFFFFU )
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{ range <<= 8; code = (code << 8) | get_byte(); }
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}
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@ -118,7 +101,7 @@ public:
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for( int i = num_bits; i > 0; --i )
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{
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symbol <<= 1;
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if( range <= 0x00FFFFFF )
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if( range <= 0x00FFFFFFU )
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{
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range <<= 7; code = (code << 8) | get_byte();
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if( code >= range ) { code -= range; symbol |= 1; }
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@ -174,16 +157,16 @@ public:
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int decode_matched( Bit_model bm[], const int match_byte )
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{
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Bit_model *bm1 = bm + 0x100;
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Bit_model * const bm1 = bm + 0x100;
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int symbol = 1;
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for( int i = 1; i <= 8; ++i )
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for( int i = 7; i >= 0; --i )
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{
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const int match_bit = ( match_byte << i ) & 0x100;
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const int bit = decode_bit( bm1[match_bit+symbol] );
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const int match_bit = ( match_byte >> i ) & 1;
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const int bit = decode_bit( bm1[(match_bit<<8)+symbol] );
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symbol = ( symbol << 1 ) | bit;
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if( ( match_bit && !bit ) || ( !match_bit && bit ) )
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if( match_bit != bit )
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{
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while( ++i <= 8 )
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while( --i >= 0 )
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symbol = ( symbol << 1 ) | decode_bit( bm[symbol] );
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break;
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}
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@ -219,16 +202,16 @@ class Literal_decoder
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{
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Bit_model bm_literal[1<<literal_context_bits][0x300];
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int state( const int prev_byte ) const throw()
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int lstate( const int prev_byte ) const throw()
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{ return ( prev_byte >> ( 8 - literal_context_bits ) ); }
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public:
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uint8_t decode( Range_decoder & range_decoder, const uint8_t prev_byte )
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{ return range_decoder.decode_tree( bm_literal[state(prev_byte)], 8 ); }
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{ return range_decoder.decode_tree( bm_literal[lstate(prev_byte)], 8 ); }
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uint8_t decode_matched( Range_decoder & range_decoder,
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const uint8_t prev_byte, const uint8_t match_byte )
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{ return range_decoder.decode_matched( bm_literal[state(prev_byte)], match_byte ); }
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{ return range_decoder.decode_matched( bm_literal[lstate(prev_byte)], match_byte ); }
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};
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@ -236,7 +219,7 @@ class LZ_decoder : public Circular_buffer
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{
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enum { min_free_bytes = max_match_len };
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long long partial_data_pos;
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const int format_version;
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const int member_version;
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const int dictionary_size;
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uint32_t crc_;
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bool member_finished_;
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@ -257,7 +240,7 @@ class LZ_decoder : public Circular_buffer
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Bit_model bm_dis[modeled_distances-end_dis_model];
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Bit_model bm_align[dis_align_size];
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Range_decoder range_decoder;
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Range_decoder & range_decoder;
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Len_decoder len_decoder;
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Len_decoder rep_match_len_decoder;
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Literal_decoder literal_decoder;
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@ -286,7 +269,7 @@ class LZ_decoder : public Circular_buffer
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std::memcpy( buffer + put, buffer + i, len );
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put += len;
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}
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else for( ; len > 0 ; --len )
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else for( ; len > 0; --len )
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{
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crc32.update( crc_, buffer[i] );
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buffer[put] = buffer[i];
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@ -298,27 +281,26 @@ class LZ_decoder : public Circular_buffer
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bool verify_trailer();
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public:
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LZ_decoder( const File_header & header, Input_buffer & ibuf )
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LZ_decoder( const File_header & header, Range_decoder & rdec )
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:
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Circular_buffer( std::max( 65536, header.dictionary_size() ) + min_free_bytes ),
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partial_data_pos( 0 ),
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format_version( header.version ),
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member_version( header.version() ),
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dictionary_size( header.dictionary_size() ),
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crc_( 0xFFFFFFFF ),
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crc_( 0xFFFFFFFFU ),
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member_finished_( false ),
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verify_trailer_pending( false ),
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rep0( 0 ),
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rep1( 0 ),
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rep2( 0 ),
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rep3( 0 ),
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range_decoder( sizeof header, ibuf ),
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literal_decoder()
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range_decoder( rdec )
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{ buffer[buffer_size-1] = 0; } // prev_byte of first_byte
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bool enough_free_bytes() const throw()
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{ return free_bytes() >= min_free_bytes; }
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uint32_t crc() const throw() { return crc_ ^ 0xFFFFFFFF; }
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uint32_t crc() const throw() { return crc_ ^ 0xFFFFFFFFU; }
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int decode_member();
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bool member_finished() const throw()
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{ return ( member_finished_ && !used_bytes() ); }
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