1 files changed, 487 insertions, 0 deletions
diff --git a/encoder_base.h b/encoder_base.h
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+++ b/encoder_base.h
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+/*  Lzip - LZMA lossless data compressor
+    Copyright (C) 2008-2015 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/>.
+*/
+
+enum { price_shift_bits = 6,
+       price_step_bits = 2,
+       price_step = 1 << price_step_bits };
+
+class Dis_slots
+  {
+  uint8_t data[1<<10];
+
+public:
+  void init()
+    {
+    for( int slot = 0; slot < 4; ++slot ) data[slot] = slot;
+    for( int i = 4, size = 2, slot = 4; slot < 20; slot += 2 )
+      {
+      std::memset( &data[i], slot, size );
+      std::memset( &data[i+size], slot + 1, size );
+      size <<= 1;
+      i += size;
+      }
+    }
+
+  uint8_t operator[]( const int dis ) const { return data[dis]; }
+  };
+
+extern Dis_slots dis_slots;
+
+inline uint8_t get_slot( const unsigned dis )
+  {
+  if( dis < (1 << 10) ) return dis_slots[dis];
+  if( dis < (1 << 19) ) return dis_slots[dis>> 9] + 18;
+  if( dis < (1 << 28) ) return dis_slots[dis>>18] + 36;
+  return dis_slots[dis>>27] + 54;
+  }
+
+
+class Prob_prices
+  {
+  short data[bit_model_total >> price_step_bits];
+
+public:
+  void init()
+    {
+    for( int i = 0; i < bit_model_total >> price_step_bits; ++i )
+      {
+      unsigned val = ( i * price_step ) + ( price_step / 2 );
+      int bits = 0;				/* base 2 logarithm of val */
+      for( int j = 0; j < price_shift_bits; ++j )
+        {
+        val = val * val;
+        bits <<= 1;
+        while( val >= 1 << 16 ) { val >>= 1; ++bits; }
+        }
+      bits += 15;				/* remaining bits in val */
+      data[i] = ( bit_model_total_bits << price_shift_bits ) - bits;
+      }
+    }
+
+  int operator[]( const int probability ) const
+    { return data[probability >> price_step_bits]; }
+  };
+
+extern Prob_prices prob_prices;
+
+
+inline int price0( const Bit_model bm )
+  { return prob_prices[bm.probability]; }
+
+inline int price1( const Bit_model bm )
+  { return prob_prices[bit_model_total - bm.probability]; }
+
+inline int price_bit( const Bit_model bm, const int bit )
+  { if( bit ) return price1( bm ); else return price0( bm ); }
+
+
+inline int price_symbol3( const Bit_model bm[], int symbol )
+  {
+  int bit = symbol & 1;
+  symbol |= 8; symbol >>= 1;
+  int price = price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  return price + price_bit( bm[1], symbol & 1 );
+  }
+
+
+inline int price_symbol6( const Bit_model bm[], int symbol )
+  {
+  int bit = symbol & 1;
+  symbol |= 64; symbol >>= 1;
+  int price = price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  return price + price_bit( bm[1], symbol & 1 );
+  }
+
+
+inline int price_symbol8( const Bit_model bm[], int symbol )
+  {
+  int bit = symbol & 1;
+  symbol |= 0x100; symbol >>= 1;
+  int price = price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+  return price + price_bit( bm[1], symbol & 1 );
+  }
+
+
+inline int price_symbol_reversed( const Bit_model bm[], int symbol,
+                                  const int num_bits )
+  {
+  int price = 0;
+  int model = 1;
+  for( int i = num_bits; i > 0; --i )
+    {
+    const int bit = symbol & 1;
+    price += price_bit( bm[model], bit );
+    model = ( model << 1 ) | bit;
+    symbol >>= 1;
+    }
+  return price;
+  }
+
+
+inline int price_matched( const Bit_model bm[], int symbol, int match_byte )
+  {
+  int price = 0;
+  int mask = 0x100;
+  symbol |= mask;
+
+  do {
+    match_byte <<= 1;
+    const int match_bit = match_byte & mask;
+    symbol <<= 1;
+    const int bit = symbol & 0x100;
+    price += price_bit( bm[match_bit+(symbol>>9)+mask], bit );
+    mask &= ~(match_byte ^ symbol);	/* if( match_bit != bit ) mask = 0; */
+    }
+  while( symbol < 0x10000 );
+  return price;
+  }
+
+
+class Matchfinder_base
+  {
+  bool read_block();
+  void normalize_pos();
+
+  Matchfinder_base( const Matchfinder_base & );	// declared as private
+  void operator=( const Matchfinder_base & );	// declared as private
+
+protected:
+  unsigned long long partial_data_pos;
+  uint8_t * buffer;		/* input buffer */
+  int32_t * prev_positions;	/* 1 + last seen position of key. else 0 */
+  int32_t * pos_array;		/* may be tree or chain */
+  const int before_size;	/* bytes to keep in buffer before dictionary */
+  int buffer_size;
+  int dictionary_size;		/* bytes to keep in buffer before pos */
+  int pos;			/* current pos in buffer */
+  int cyclic_pos;		/* cycles through [0, dictionary_size] */
+  int stream_pos;		/* first byte not yet read from file */
+  int pos_limit;		/* when reached, a new block must be read */
+  int key4_mask;
+  int num_prev_positions;	/* size of prev_positions */
+  int pos_array_size;
+  const int infd;		/* input file descriptor */
+  bool at_stream_end;		/* stream_pos shows real end of file */
+
+  Matchfinder_base( const int before, const int dict_size,
+                    const int after_size, const int dict_factor,
+                    const int num_prev_positions23,
+                    const int pos_array_factor, const int ifd );
+
+  ~Matchfinder_base()
+    { delete[] prev_positions; std::free( buffer ); }
+
+public:
+  uint8_t peek( const int distance ) const { return buffer[pos-distance]; }
+  int available_bytes() const { return stream_pos - pos; }
+  unsigned long long data_position() const { return partial_data_pos + pos; }
+  bool data_finished() const { return at_stream_end && pos >= stream_pos; }
+  const uint8_t * ptr_to_current_pos() const { return buffer + pos; }
+
+  int true_match_len( const int index, const int distance, int len_limit ) const
+    {
+    const uint8_t * const data = buffer + pos + index;
+    int i = 0;
+    if( index + len_limit > available_bytes() )
+      len_limit = available_bytes() - index;
+    while( i < len_limit && data[i-distance] == data[i] ) ++i;
+    return i;
+    }
+
+  void move_pos()
+    {
+    if( ++cyclic_pos > dictionary_size ) cyclic_pos = 0;
+    if( ++pos >= pos_limit ) normalize_pos();
+    }
+
+  void reset();
+  };
+
+
+class Range_encoder
+  {
+  enum { buffer_size = 65536 };
+  uint64_t low;
+  unsigned long long partial_member_pos;
+  uint8_t * const buffer;	/* output buffer */
+  int pos;			/* current pos in buffer */
+  uint32_t range;
+  unsigned ff_count;
+  const int outfd;		/* output file descriptor */
+  uint8_t cache;
+  File_header header;
+
+  void shift_low()
+    {
+    const bool carry = ( low > 0xFFFFFFFFU );
+    if( carry || low < 0xFF000000U )
+      {
+      put_byte( cache + carry );
+      for( ; ff_count > 0; --ff_count ) put_byte( 0xFF + carry );
+      cache = low >> 24;
+      }
+    else ++ff_count;
+    low = ( low & 0x00FFFFFFU ) << 8;
+    }
+
+  Range_encoder( const Range_encoder & );	// declared as private
+  void operator=( const Range_encoder & );	// declared as private
+
+public:
+  void reset()
+    {
+    low = 0;
+    partial_member_pos = 0;
+    pos = 0;
+    range = 0xFFFFFFFFU;
+    ff_count = 0;
+    cache = 0;
+    for( int i = 0; i < File_header::size; ++i )
+      put_byte( header.data[i] );
+    }
+
+  Range_encoder( const unsigned dictionary_size, const int ofd )
+    :
+    buffer( new uint8_t[buffer_size] ),
+    outfd( ofd )
+    {
+    header.set_magic();
+    header.dictionary_size( dictionary_size );
+    reset();
+    }
+
+  ~Range_encoder() { delete[] buffer; }
+
+  unsigned long long member_position() const
+    { return partial_member_pos + pos + ff_count; }
+
+  void flush() { for( int i = 0; i < 5; ++i ) shift_low(); }
+  void flush_data();
+
+  void put_byte( const uint8_t b )
+    {
+    buffer[pos] = b;
+    if( ++pos >= buffer_size ) flush_data();
+    }
+
+  void encode( const int symbol, const int num_bits )
+    {
+    for( int i = num_bits - 1; i >= 0; --i )
+      {
+      range >>= 1;
+      if( (symbol >> i) & 1 ) low += range;
+      if( range <= 0x00FFFFFFU ) { range <<= 8; shift_low(); }
+      }
+    }
+
+  void encode_bit( Bit_model & bm, const int bit )
+    {
+    const uint32_t bound = ( range >> bit_model_total_bits ) * bm.probability;
+    if( !bit )
+      {
+      range = bound;
+      bm.probability += (bit_model_total - bm.probability) >> bit_model_move_bits;
+      }
+    else
+      {
+      low += bound;
+      range -= bound;
+      bm.probability -= bm.probability >> bit_model_move_bits;
+      }
+    if( range <= 0x00FFFFFFU ) { range <<= 8; shift_low(); }
+    }
+
+  void encode_tree3( Bit_model bm[], const int symbol )
+    {
+    int model = 1;
+    int bit = ( symbol >> 2 ) & 1;
+    encode_bit( bm[model], bit ); model = ( model << 1 ) | bit;
+    bit = ( symbol >> 1 ) & 1;
+    encode_bit( bm[model], bit ); model = ( model << 1 ) | bit;
+    encode_bit( bm[model], symbol & 1 );
+    }
+
+  void encode_tree6( Bit_model bm[], const int symbol )
+    {
+    int model = 1;
+    int bit = ( symbol >> 5 ) & 1;
+    encode_bit( bm[model], bit ); model = ( model << 1 ) | bit;
+    bit = ( symbol >> 4 ) & 1;
+    encode_bit( bm[model], bit ); model = ( model << 1 ) | bit;
+    bit = ( symbol >> 3 ) & 1;
+    encode_bit( bm[model], bit ); model = ( model << 1 ) | bit;
+    bit = ( symbol >> 2 ) & 1;
+    encode_bit( bm[model], bit ); model = ( model << 1 ) | bit;
+    bit = ( symbol >> 1 ) & 1;
+    encode_bit( bm[model], bit ); model = ( model << 1 ) | bit;
+    encode_bit( bm[model], symbol & 1 );
+    }
+
+  void encode_tree8( Bit_model bm[], const int symbol )
+    {
+    int model = 1;
+    int mask = ( 1 << 7 );
+    do {
+      const int bit = ( symbol & mask );
+      encode_bit( bm[model], bit );
+      model <<= 1; if( bit ) ++model;
+      }
+    while( mask >>= 1 );
+    }
+
+  void encode_tree_reversed( Bit_model bm[], int symbol, const int num_bits )
+    {
+    int model = 1;
+    for( int i = num_bits; i > 0; --i )
+      {
+      const int bit = symbol & 1;
+      encode_bit( bm[model], bit );
+      model = ( model << 1 ) | bit;
+      symbol >>= 1;
+      }
+    }
+
+  void encode_matched( Bit_model bm[], int symbol, int match_byte )
+    {
+    int mask = 0x100;
+    symbol |= mask;
+
+    do {
+      match_byte <<= 1;
+      const int match_bit = match_byte & mask;
+      symbol <<= 1;
+      const int bit = symbol & 0x100;
+      encode_bit( bm[match_bit+(symbol>>9)+mask], bit );
+      mask &= ~(match_byte ^ symbol);	/* if( match_bit != bit ) mask = 0; */
+      }
+    while( symbol < 0x10000 );
+    }
+
+  void encode_len( Len_model & lm, int symbol, const int pos_state )
+    {
+    symbol -= min_match_len;
+    bool bit = ( symbol >= len_low_symbols );
+    encode_bit( lm.choice1, bit );
+    if( !bit )
+      encode_tree3( lm.bm_low[pos_state], symbol );
+    else
+      {
+      bit = ( symbol >= len_low_symbols + len_mid_symbols );
+      encode_bit( lm.choice2, bit );
+      if( !bit )
+        encode_tree3( lm.bm_mid[pos_state], symbol - len_low_symbols );
+      else
+        encode_tree8( lm.bm_high, symbol - len_low_symbols - len_mid_symbols );
+      }
+    }
+  };
+
+
+class LZ_encoder_base : public Matchfinder_base
+  {
+protected:
+  enum { max_marker_size = 16,
+         num_rep_distances = 4 };	/* must be 4 */
+
+  uint32_t crc_;
+
+  Bit_model bm_literal[1<<literal_context_bits][0x300];
+  Bit_model bm_match[State::states][pos_states];
+  Bit_model bm_rep[State::states];
+  Bit_model bm_rep0[State::states];
+  Bit_model bm_rep1[State::states];
+  Bit_model bm_rep2[State::states];
+  Bit_model bm_len[State::states][pos_states];
+  Bit_model bm_dis_slot[len_states][1<<dis_slot_bits];
+  Bit_model bm_dis[modeled_distances-end_dis_model];
+  Bit_model bm_align[dis_align_size];
+  Len_model match_len_model;
+  Len_model rep_len_model;
+  Range_encoder renc;
+
+  LZ_encoder_base( const int before, const int dict_size, const int after_size,
+                   const int dict_factor, const int num_prev_positions23,
+                   const int pos_array_factor, const int ifd, const int outfd )
+    :
+    Matchfinder_base( before, dict_size, after_size, dict_factor,
+                      num_prev_positions23, pos_array_factor, ifd ),
+    crc_( 0xFFFFFFFFU ),
+    renc( dictionary_size, outfd )
+    {}
+
+  unsigned crc() const { return crc_ ^ 0xFFFFFFFFU; }
+
+  int price_literal( const uint8_t prev_byte, const uint8_t symbol ) const
+    { return price_symbol8( bm_literal[get_lit_state(prev_byte)], symbol ); }
+
+  int price_matched( const uint8_t prev_byte, const uint8_t symbol,
+                     const uint8_t match_byte ) const
+    { return ::price_matched( bm_literal[get_lit_state(prev_byte)], symbol,
+                              match_byte ); }
+
+  void encode_literal( const uint8_t prev_byte, const uint8_t symbol )
+    { renc.encode_tree8( bm_literal[get_lit_state(prev_byte)], symbol ); }
+
+  void encode_matched( const uint8_t prev_byte, const uint8_t symbol,
+                       const uint8_t match_byte )
+    { renc.encode_matched( bm_literal[get_lit_state(prev_byte)], symbol,
+                           match_byte ); }
+
+  void encode_pair( const unsigned dis, const int len, const int pos_state )
+    {
+    renc.encode_len( match_len_model, len, pos_state );
+    const int dis_slot = get_slot( dis );
+    renc.encode_tree6( bm_dis_slot[get_len_state(len)], dis_slot );
+
+    if( dis_slot >= start_dis_model )
+      {
+      const int direct_bits = ( dis_slot >> 1 ) - 1;
+      const unsigned base = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
+      const unsigned direct_dis = dis - base;
+
+      if( dis_slot < end_dis_model )
+        renc.encode_tree_reversed( bm_dis + base - dis_slot - 1, direct_dis,
+                                   direct_bits );
+      else
+        {
+        renc.encode( direct_dis >> dis_align_bits, direct_bits - dis_align_bits );
+        renc.encode_tree_reversed( bm_align, direct_dis, dis_align_bits );
+        }
+      }
+    }
+
+  void full_flush( const State state );
+
+public:
+  virtual ~LZ_encoder_base() {}
+
+  unsigned long long member_position() const { return renc.member_position(); }
+  virtual void reset();
+
+  virtual bool encode_member( const unsigned long long member_size ) = 0;
+  };