Adding upstream version 1.13~rc1.upstream/1.13_rc1

Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>

1 files changed, 268 insertions, 0 deletions

diff --git a/decoder.h b/decoder.h
new file mode 100644
index 0000000..3b5dc7d
--- /dev/null
+++ b/decoder.h
@@ -0,0 +1,268 @@
+/*  Lziprecover - Data recovery tool for lzipped files
+    Copyright (C) 2009, 2010, 2011 Antonio Diaz Diaz.
+
+    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 3 of the License, or
+    (at your option) 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, see <http://www.gnu.org/licenses/>.
+*/
+
+class Range_decoder
+  {
+  enum { buffer_size = 16384 };
+  long long partial_member_pos;
+  uint8_t * const buffer;	// input buffer
+  int pos;			// current pos in buffer
+  int stream_pos;		// when reached, a new block must be read
+  uint32_t code;
+  uint32_t range;
+  const int infd;		// input file descriptor
+  bool at_stream_end;
+
+  bool read_block();
+
+public:
+  Range_decoder( const int ifd )
+    :
+    partial_member_pos( 0 ),
+    buffer( new uint8_t[buffer_size] ),
+    pos( 0 ),
+    stream_pos( 0 ),
+    code( 0 ),
+    range( 0xFFFFFFFFU ),
+    infd( ifd ),
+    at_stream_end( false ) {}
+
+  ~Range_decoder() { delete[] buffer; }
+
+  bool code_is_zero() const throw() { return ( code == 0 ); }
+  bool finished() { return pos >= stream_pos && !read_block(); }
+  long long member_position() const throw()
+    { return partial_member_pos + pos; }
+  void reset_member_position() throw()
+    { partial_member_pos = -pos; }
+
+  uint8_t get_byte()
+    {
+    if( finished() ) return 0x55;		// make code != 0
+    return buffer[pos++];
+    }
+
+  void load()
+    {
+    code = 0;
+    range = 0xFFFFFFFFU;
+    for( int i = 0; i < 5; ++i ) code = (code << 8) | get_byte();
+    }
+
+  void normalize()
+    {
+    if( range <= 0x00FFFFFFU )
+      { range <<= 8; code = (code << 8) | get_byte(); }
+    }
+
+  int decode( const int num_bits )
+    {
+    int symbol = 0;
+    for( int i = num_bits; i > 0; --i )
+      {
+      symbol <<= 1;
+      if( range <= 0x00FFFFFFU )
+        {
+        range <<= 7; code = (code << 8) | get_byte();
+        if( code >= range ) { code -= range; symbol |= 1; }
+        }
+      else
+        {
+        range >>= 1;
+        if( code >= range ) { code -= range; symbol |= 1; }
+        }
+      }
+    return symbol;
+    }
+
+  int decode_bit( Bit_model & bm )
+    {
+    normalize();
+    const uint32_t bound = ( range >> bit_model_total_bits ) * bm.probability;
+    if( code < bound )
+      {
+      range = bound;
+      bm.probability += (bit_model_total - bm.probability) >> bit_model_move_bits;
+      return 0;
+      }
+    else
+      {
+      range -= bound;
+      code -= bound;
+      bm.probability -= bm.probability >> bit_model_move_bits;
+      return 1;
+      }
+    }
+
+  int decode_tree( Bit_model bm[], const int num_bits )
+    {
+    int model = 1;
+    for( int i = num_bits; i > 0; --i )
+      model = ( model << 1 ) | decode_bit( bm[model] );
+    return model - (1 << num_bits);
+    }
+
+  int decode_tree_reversed( Bit_model bm[], const int num_bits )
+    {
+    int model = 1;
+    int symbol = 0;
+    for( int i = 0; i < num_bits; ++i )
+      {
+      const int bit = decode_bit( bm[model] );
+      model <<= 1;
+      if( bit ) { model |= 1; symbol |= (1 << i); }
+      }
+    return symbol;
+    }
+
+  int decode_matched( Bit_model bm[], const int match_byte )
+    {
+    Bit_model * const bm1 = bm + 0x100;
+    int symbol = 1;
+    for( int i = 7; i >= 0; --i )
+      {
+      const int match_bit = ( match_byte >> i ) & 1;
+      const int bit = decode_bit( bm1[(match_bit<<8)+symbol] );
+      symbol = ( symbol << 1 ) | bit;
+      if( match_bit != bit )
+        {
+        while( --i >= 0 )
+          symbol = ( symbol << 1 ) | decode_bit( bm[symbol] );
+        break;
+        }
+      }
+    return symbol & 0xFF;
+    }
+  };
+
+
+class Len_decoder
+  {
+  Bit_model choice1;
+  Bit_model choice2;
+  Bit_model bm_low[pos_states][len_low_symbols];
+  Bit_model bm_mid[pos_states][len_mid_symbols];
+  Bit_model bm_high[len_high_symbols];
+
+public:
+  int decode( Range_decoder & range_decoder, const int pos_state )
+    {
+    if( range_decoder.decode_bit( choice1 ) == 0 )
+      return range_decoder.decode_tree( bm_low[pos_state], len_low_bits );
+    if( range_decoder.decode_bit( choice2 ) == 0 )
+      return len_low_symbols +
+             range_decoder.decode_tree( bm_mid[pos_state], len_mid_bits );
+    return len_low_symbols + len_mid_symbols +
+           range_decoder.decode_tree( bm_high, len_high_bits );
+    }
+  };
+
+
+class Literal_decoder
+  {
+  Bit_model bm_literal[1<<literal_context_bits][0x300];
+
+  int lstate( const int prev_byte ) const throw()
+    { return ( prev_byte >> ( 8 - literal_context_bits ) ); }
+
+public:
+  uint8_t decode( Range_decoder & range_decoder, const uint8_t prev_byte )
+    { return range_decoder.decode_tree( bm_literal[lstate(prev_byte)], 8 ); }
+
+  uint8_t decode_matched( Range_decoder & range_decoder,
+                          const uint8_t prev_byte, const uint8_t match_byte )
+    { return range_decoder.decode_matched( bm_literal[lstate(prev_byte)],
+                                           match_byte ); }
+  };
+
+
+class LZ_decoder
+  {
+  long long partial_data_pos;
+  const int dictionary_size;
+  const int buffer_size;
+  uint8_t * const buffer;	// output buffer
+  int pos;			// current pos in buffer
+  int stream_pos;		// first byte not yet written to file
+  uint32_t crc_;
+  const int outfd;		// output file descriptor
+  const int member_version;
+  Range_decoder & range_decoder;
+
+  void flush_data();
+  bool verify_trailer( const Pretty_print & pp ) const;
+
+  uint8_t get_prev_byte() const throw()
+    {
+    const int i = ( ( pos > 0 ) ? pos : buffer_size ) - 1;
+    return buffer[i];
+    }
+
+  uint8_t get_byte( const int distance ) const throw()
+    {
+    int i = pos - distance - 1;
+    if( i < 0 ) i += buffer_size;
+    return buffer[i];
+    }
+
+  void put_byte( const uint8_t b )
+    {
+    buffer[pos] = b;
+    if( ++pos >= buffer_size ) flush_data();
+    }
+
+  void copy_block( const int distance, int len )
+    {
+    int i = pos - distance - 1;
+    if( i < 0 ) i += buffer_size;
+    if( len < buffer_size - std::max( pos, i ) && len <= std::abs( pos - i ) )
+      {
+      std::memcpy( buffer + pos, buffer + i, len );
+      pos += len;
+      }
+    else for( ; len > 0; --len )
+      {
+      buffer[pos] = buffer[i];
+      if( ++pos >= buffer_size ) flush_data();
+      if( ++i >= buffer_size ) i = 0;
+      }
+    }
+
+public:
+  LZ_decoder( const File_header & header, Range_decoder & rdec, const int ofd )
+    :
+    partial_data_pos( 0 ),
+    dictionary_size( header.dictionary_size() ),
+    buffer_size( std::max( 65536, dictionary_size ) ),
+    buffer( new uint8_t[buffer_size] ),
+    pos( 0 ),
+    stream_pos( 0 ),
+    crc_( 0xFFFFFFFFU ),
+    outfd( ofd ),
+    member_version( header.version() ),
+    range_decoder( rdec )
+    { buffer[buffer_size-1] = 0; }	// prev_byte of first_byte
+
+  ~LZ_decoder() { delete[] buffer; }
+
+  uint32_t crc() const throw() { return crc_ ^ 0xFFFFFFFFU; }
+
+  long long data_position() const throw()
+    { return partial_data_pos + pos; }
+
+  int decode_member( const Pretty_print & pp );
+  };