Adding upstream version 1.23.upstream/1.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 383 insertions, 0 deletions

diff --git a/decoder.h b/decoder.h
new file mode 100644
index 0000000..5b06b25
--- /dev/null
+++ b/decoder.h
@@ -0,0 +1,383 @@
+/* Lziprecover - Data recovery tool for the lzip format
+   Copyright (C) 2009-2022 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 2 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 };
+  unsigned 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();
+
+  Range_decoder( const Range_decoder & );	// declared as private
+  void operator=( const Range_decoder & );	// declared as private
+
+public:
+  explicit 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; }
+
+  unsigned get_code() const { return code; }
+  bool finished() { return pos >= stream_pos && !read_block(); }
+
+  unsigned long long member_position() const
+    { return partial_member_pos + pos; }
+
+  void reset_member_position()
+    { partial_member_pos = 0; partial_member_pos -= pos; }
+
+  uint8_t get_byte()
+    {
+    // 0xFF avoids decoder error if member is truncated at EOS marker
+    if( finished() ) return 0xFF;
+    return buffer[pos++];
+    }
+
+  int read_data( uint8_t * const outbuf, const int size )
+    {
+    int sz = 0;
+    while( sz < size && !finished() )
+      {
+      const int rd = std::min( size - sz, stream_pos - pos );
+      std::memcpy( outbuf + sz, buffer + pos, rd );
+      pos += rd;
+      sz += rd;
+      }
+    return sz;
+    }
+
+  /* if ignore_errors, stop reading before the first wrong byte, so that
+     unreading the header is not required to sync to next member */
+  int read_header_carefully( Lzip_header & header, const bool ignore_errors )
+    {
+    int sz = 0;
+    while( sz < Lzip_header::size && !finished() )
+      {
+      header.data[sz] = buffer[pos];
+      if( ignore_errors &&
+          ( ( sz < 4 && header.data[sz] != lzip_magic[sz] ) ||
+            ( sz == 4 && !header.verify_version() ) ||
+            ( sz == 5 && !isvalid_ds( header.dictionary_size() ) ) ) ) break;
+      ++pos; ++sz;
+      }
+    return sz;
+    }
+
+  bool find_header( Lzip_header & header )
+    {
+    while( !finished() )
+      {
+      if( buffer[pos] != lzip_magic[0] ) { ++pos; continue; }
+      reset_member_position();
+      Lzip_header h;
+      if( read_header_carefully( h, true ) == Lzip_header::size )
+        { header = h; return true; }
+      }
+    return false;
+    }
+
+  void load()
+    {
+    code = 0;
+    for( int i = 0; i < 5; ++i ) code = ( code << 8 ) | get_byte();
+    range = 0xFFFFFFFFU;
+    code &= range;		// make sure that first byte is discarded
+    }
+
+  void normalize()
+    {
+    if( range <= 0x00FFFFFFU )
+      { range <<= 8; code = ( code << 8 ) | get_byte(); }
+    }
+
+  unsigned decode( const int num_bits )
+    {
+    unsigned symbol = 0;
+    for( int i = num_bits; i > 0; --i )
+      {
+      normalize();
+      range >>= 1;
+//      symbol <<= 1;
+//      if( code >= range ) { code -= range; symbol |= 1; }
+      const bool bit = ( code >= range );
+      symbol <<= 1; symbol += bit;
+      code -= range & ( 0U - bit );
+      }
+    return symbol;
+    }
+
+  unsigned 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
+      {
+      code -= bound;
+      range -= bound;
+      bm.probability -= bm.probability >> bit_model_move_bits;
+      return 1;
+      }
+    }
+
+  void decode_symbol_bit( Bit_model & bm, unsigned & symbol )
+    {
+    normalize();
+    symbol <<= 1;
+    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;
+      }
+    else
+      {
+      code -= bound;
+      range -= bound;
+      bm.probability -= bm.probability >> bit_model_move_bits;
+      symbol |= 1;
+      }
+    }
+
+  void decode_symbol_bit_reversed( Bit_model & bm, unsigned & model,
+                                   unsigned & symbol, const int i )
+    {
+    normalize();
+    model <<= 1;
+    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;
+      }
+    else
+      {
+      code -= bound;
+      range -= bound;
+      bm.probability -= bm.probability >> bit_model_move_bits;
+      model |= 1;
+      symbol |= 1 << i;
+      }
+    }
+
+  unsigned decode_tree6( Bit_model bm[] )
+    {
+    unsigned symbol = 1;
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    return symbol & 0x3F;
+    }
+
+  unsigned decode_tree8( Bit_model bm[] )
+    {
+    unsigned symbol = 1;
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    return symbol & 0xFF;
+    }
+
+  unsigned decode_tree_reversed( Bit_model bm[], const int num_bits )
+    {
+    unsigned model = 1;
+    unsigned symbol = 0;
+    for( int i = 0; i < num_bits; ++i )
+      decode_symbol_bit_reversed( bm[model], model, symbol, i );
+    return symbol;
+    }
+
+  unsigned decode_tree_reversed4( Bit_model bm[] )
+    {
+    unsigned model = 1;
+    unsigned symbol = 0;
+    decode_symbol_bit_reversed( bm[model], model, symbol, 0 );
+    decode_symbol_bit_reversed( bm[model], model, symbol, 1 );
+    decode_symbol_bit_reversed( bm[model], model, symbol, 2 );
+    decode_symbol_bit_reversed( bm[model], model, symbol, 3 );
+    return symbol;
+    }
+
+  unsigned decode_matched( Bit_model bm[], unsigned match_byte )
+    {
+    Bit_model * const bm1 = bm + 0x100;
+    unsigned symbol = 1;
+    while( symbol < 0x100 )
+      {
+      const unsigned match_bit = ( match_byte <<= 1 ) & 0x100;
+      const bool bit = decode_bit( bm1[symbol+match_bit] );
+      symbol <<= 1; symbol |= bit;
+      if( match_bit >> 8 != bit )
+        {
+        while( symbol < 0x100 ) decode_symbol_bit( bm[symbol], symbol );
+        break;
+        }
+      }
+    return symbol & 0xFF;
+    }
+
+  unsigned decode_len( Len_model & lm, const int pos_state )
+    {
+    Bit_model * bm;
+    unsigned mask, offset, symbol = 1;
+
+    if( decode_bit( lm.choice1 ) == 0 )
+      { bm = lm.bm_low[pos_state]; mask = 7; offset = 0; goto len3; }
+    if( decode_bit( lm.choice2 ) == 0 )
+      { bm = lm.bm_mid[pos_state]; mask = 7; offset = len_low_symbols; goto len3; }
+    bm = lm.bm_high; mask = 0xFF; offset = len_low_symbols + len_mid_symbols;
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+len3:
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    decode_symbol_bit( bm[symbol], symbol );
+    return ( symbol & mask ) + min_match_len + offset;
+    }
+  };
+
+
+class LZ_decoder
+  {
+  const unsigned long long outskip;
+  const unsigned long long outend;
+  unsigned long long partial_data_pos;
+  Range_decoder & rdec;
+  const unsigned dictionary_size;
+  uint8_t * const buffer;	// output buffer
+  unsigned pos;			// current pos in buffer
+  unsigned stream_pos;		// first byte not yet written to file
+  uint32_t crc_;
+  const int outfd;		// output file descriptor
+  bool pos_wrapped;
+
+  unsigned long long stream_position() const
+    { return partial_data_pos + stream_pos; }
+  void flush_data();
+  bool verify_trailer( const Pretty_print & pp ) const;
+
+  uint8_t peek_prev() const
+    { return buffer[((pos > 0) ? pos : dictionary_size)-1]; }
+
+  uint8_t peek( const unsigned distance ) const
+    {
+    const unsigned i = ( ( pos > distance ) ? 0 : dictionary_size ) +
+                       pos - distance - 1;
+    return buffer[i];
+    }
+
+  void put_byte( const uint8_t b )
+    {
+    buffer[pos] = b;
+    if( ++pos >= dictionary_size ) flush_data();
+    }
+
+  void copy_block( const unsigned distance, unsigned len )
+    {
+    unsigned lpos = pos, i = lpos - distance - 1;
+    bool fast, fast2;
+    if( lpos > distance )
+      {
+      fast = ( len < dictionary_size - lpos );
+      fast2 = ( fast && len <= lpos - i );
+      }
+    else
+      {
+      i += dictionary_size;
+      fast = ( len < dictionary_size - i );	// (i == pos) may happen
+      fast2 = ( fast && len <= i - lpos );
+      }
+    if( fast )					// no wrap
+      {
+      pos += len;
+      if( fast2 )				// no wrap, no overlap
+        std::memcpy( buffer + lpos, buffer + i, len );
+      else
+        for( ; len > 0; --len ) buffer[lpos++] = buffer[i++];
+      }
+    else for( ; len > 0; --len )
+      {
+      buffer[pos] = buffer[i];
+      if( ++pos >= dictionary_size ) flush_data();
+      if( ++i >= dictionary_size ) i = 0;
+      }
+    }
+
+  LZ_decoder( const LZ_decoder & );		// declared as private
+  void operator=( const LZ_decoder & );		// declared as private
+
+public:
+  LZ_decoder( Range_decoder & rde, const unsigned dict_size, const int ofd,
+              const unsigned long long oskip = 0,
+              const unsigned long long oend = -1ULL )
+    :
+    outskip( oskip ),
+    outend( oend ),
+    partial_data_pos( 0 ),
+    rdec( rde ),
+    dictionary_size( dict_size ),
+    buffer( new uint8_t[dictionary_size] ),
+    pos( 0 ),
+    stream_pos( 0 ),
+    crc_( 0xFFFFFFFFU ),
+    outfd( ofd ),
+    pos_wrapped( false )
+    // prev_byte of first byte; also for peek( 0 ) on corrupt file
+    { buffer[dictionary_size-1] = 0; }
+
+  ~LZ_decoder() { delete[] buffer; }
+
+  unsigned crc() const { return crc_ ^ 0xFFFFFFFFU; }
+  unsigned long long data_position() const { return partial_data_pos + pos; }
+
+  int decode_member( const Pretty_print & pp );
+  };