path: root/encoder.c

/*  Clzip - LZMA lossless data compressor
    Copyright (C) 2010, 2011, 2012, 2013 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/>.
*/

#define _FILE_OFFSET_BITS 64

#include <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include "lzip.h"
#include "encoder.h"


Dis_slots dis_slots;
Prob_prices prob_prices;


bool Mf_read_block( struct Matchfinder * const mf )
  {
  if( !mf->at_stream_end && mf->stream_pos < mf->buffer_size )
    {
    const int size = mf->buffer_size - mf->stream_pos;
    const int rd = readblock( mf->infd, mf->buffer + mf->stream_pos, size );
    mf->stream_pos += rd;
    if( rd != size && errno )
      { show_error( "Read error", errno, false ); cleanup_and_fail( 1 ); }
    if( rd < size )
      { mf->at_stream_end = true; mf->pos_limit = mf->buffer_size; }
    }
  return mf->pos < mf->stream_pos;
  }


void Mf_normalize_pos( struct Matchfinder * const mf )
  {
  if( mf->pos > mf->stream_pos )
    internal_error( "pos > stream_pos in Mf_normalize_pos" );
  if( !mf->at_stream_end )
    {
    int i;
    const int offset = mf->pos - mf->dictionary_size - before_size;
    const int size = mf->stream_pos - offset;
    memmove( mf->buffer, mf->buffer + offset, size );
    mf->partial_data_pos += offset;
    mf->pos -= offset;
    mf->stream_pos -= offset;
    for( i = 0; i < mf->num_prev_positions; ++i )
      if( mf->prev_positions[i] >= 0 ) mf->prev_positions[i] -= offset;
    for( i = 0; i < 2 * ( mf->dictionary_size + 1 ); ++i )
      if( mf->prev_pos_tree[i] >= 0 ) mf->prev_pos_tree[i] -= offset;
    Mf_read_block( mf );
    }
  }


bool Mf_init( struct Matchfinder * const mf,
              const int dict_size, const int match_len_limit, const int ifd )
  {
  const int buffer_size_limit = ( 2 * dict_size ) + before_size + after_size;
  unsigned size;
  int i;

  mf->partial_data_pos = 0;
  mf->match_len_limit = match_len_limit;
  mf->pos = 0;
  mf->cyclic_pos = 0;
  mf->stream_pos = 0;
  mf->cycles = ( match_len_limit < max_match_len ) ?
               16 + ( match_len_limit / 2 ) : 256;
  mf->infd = ifd;
  mf->at_stream_end = false;

  mf->buffer_size = max( 65536, dict_size );
  mf->buffer = (uint8_t *)malloc( mf->buffer_size );
  if( !mf->buffer ) return false;
  if( Mf_read_block( mf ) && !mf->at_stream_end &&
      mf->buffer_size < buffer_size_limit )
    {
    uint8_t * tmp;
    mf->buffer_size = buffer_size_limit;
    tmp = (uint8_t *)realloc( mf->buffer, mf->buffer_size );
    if( !tmp ) { free( mf->buffer ); return false; }
    mf->buffer = tmp;
    Mf_read_block( mf );
    }
  if( mf->at_stream_end && mf->stream_pos < dict_size )
    mf->dictionary_size = max( min_dictionary_size, mf->stream_pos );
  else
    mf->dictionary_size = dict_size;
  mf->pos_limit = mf->buffer_size;
  if( !mf->at_stream_end ) mf->pos_limit -= after_size;
  size = 1 << max( 16, real_bits( mf->dictionary_size - 1 ) - 2 );
  if( mf->dictionary_size > 1 << 26 )		/* 64 MiB */
    size >>= 1;
  mf->key4_mask = size - 1;
  size += num_prev_positions2;
  size += num_prev_positions3;

  mf->num_prev_positions = size;
  size += ( 2 * ( mf->dictionary_size + 1 ) );
  if( size * sizeof (int32_t) <= size ) mf->prev_positions = 0;
  else mf->prev_positions = (int32_t *)malloc( size * sizeof (int32_t) );
  if( !mf->prev_positions ) { free( mf->buffer ); return false; }
  mf->prev_pos_tree = mf->prev_positions + mf->num_prev_positions;
  for( i = 0; i < mf->num_prev_positions; ++i ) mf->prev_positions[i] = -1;
  return true;
  }


void Mf_reset( struct Matchfinder * const mf )
  {
  int i;
  const int size = mf->stream_pos - mf->pos;
  if( size > 0 ) memmove( mf->buffer, mf->buffer + mf->pos, size );
  mf->partial_data_pos = 0;
  mf->stream_pos -= mf->pos;
  mf->pos = 0;
  mf->cyclic_pos = 0;
  for( i = 0; i < mf->num_prev_positions; ++i ) mf->prev_positions[i] = -1;
  Mf_read_block( mf );
  }


int Mf_get_match_pairs( struct Matchfinder * const mf, struct Pair * pairs )
  {
  int32_t * ptr0 = mf->prev_pos_tree + ( mf->cyclic_pos << 1 );
  int32_t * ptr1 = ptr0 + 1;
  int32_t * newptr;
  int len = 0, len0 = 0, len1 = 0;
  int maxlen = min_match_len - 1;
  int num_pairs = 0;
  const int min_pos = (mf->pos > mf->dictionary_size) ?
                       mf->pos - mf->dictionary_size : 0;
  const uint8_t * const data = mf->buffer + mf->pos;
  int count, delta, key2, key3, key4, newpos;
  unsigned tmp;
  int len_limit = mf->match_len_limit;

  if( len_limit > Mf_available_bytes( mf ) )
    {
    len_limit = Mf_available_bytes( mf );
    if( len_limit < 4 ) return 0;
    }

  tmp = crc32[data[0]] ^ data[1];
  key2 = tmp & ( num_prev_positions2 - 1 );
  tmp ^= (uint32_t)data[2] << 8;
  key3 = num_prev_positions2 + ( tmp & ( num_prev_positions3 - 1 ) );
  key4 = num_prev_positions2 + num_prev_positions3 +
         ( ( tmp ^ ( crc32[data[3]] << 5 ) ) & mf->key4_mask );

  if( pairs )
    {
    int np2 = mf->prev_positions[key2];
    int np3 = mf->prev_positions[key3];
    if( np2 >= min_pos && mf->buffer[np2] == data[0] )
      {
      pairs[0].dis = mf->pos - np2 - 1;
      pairs[0].len = maxlen = 2;
      num_pairs = 1;
      }
    if( np2 != np3 && np3 >= min_pos && mf->buffer[np3] == data[0] )
      {
      maxlen = 3;
      pairs[num_pairs].dis = mf->pos - np3 - 1;
      ++num_pairs;
      np2 = np3;
      }
    if( num_pairs > 0 )
      {
      delta = mf->pos - np2;
      while( maxlen < len_limit && data[maxlen-delta] == data[maxlen] )
        ++maxlen;
      pairs[num_pairs-1].len = maxlen;
      if( maxlen >= len_limit ) pairs = 0;
      }
    if( maxlen < 3 ) maxlen = 3;
    }

  mf->prev_positions[key2] = mf->pos;
  mf->prev_positions[key3] = mf->pos;
  newpos = mf->prev_positions[key4];
  mf->prev_positions[key4] = mf->pos;

  for( count = mf->cycles; ; )
    {
    if( newpos < min_pos || --count < 0 ) { *ptr0 = *ptr1 = -1; break; }

    delta = mf->pos - newpos;
    newptr = mf->prev_pos_tree +
      ( ( mf->cyclic_pos - delta +
          ( (mf->cyclic_pos >= delta) ? 0 : mf->dictionary_size + 1 ) ) << 1 );
    if( data[len-delta] == data[len] )
      {
      while( ++len < len_limit && data[len-delta] == data[len] ) {}
      if( pairs && maxlen < len )
        {
        pairs[num_pairs].dis = delta - 1;
        pairs[num_pairs].len = maxlen = len;
        ++num_pairs;
        }
      if( len >= len_limit )
        {
        *ptr0 = newptr[0];
        *ptr1 = newptr[1];
        break;
        }
      }
    if( data[len-delta] < data[len] )
      {
      *ptr0 = newpos;
      ptr0 = newptr + 1;
      newpos = *ptr0;
      len0 = len; if( len1 < len ) len = len1;
      }
    else
      {
      *ptr1 = newpos;
      ptr1 = newptr;
      newpos = *ptr1;
      len1 = len; if( len0 < len ) len = len0;
      }
    }
  return num_pairs;
  }


void Re_flush_data( struct Range_encoder * const renc )
  {
  if( renc->pos > 0 )
    {
    if( renc->outfd >= 0 &&
        writeblock( renc->outfd, renc->buffer, renc->pos ) != renc->pos )
      { show_error( "Write error", errno, false ); cleanup_and_fail( 1 ); }
    renc->partial_member_pos += renc->pos;
    renc->pos = 0;
    if( verbosity >= 2 ) show_progress( 0, 0, 0, 0 );
    }
  }


void Lee_encode( struct Len_encoder * const len_encoder,
                 struct Range_encoder * const renc,
                 int symbol, const int pos_state )
  {
  symbol -= min_match_len;
  if( symbol < len_low_symbols )
    {
    Re_encode_bit( renc, &len_encoder->lm.choice1, 0 );
    Re_encode_tree( renc, len_encoder->lm.bm_low[pos_state], symbol, len_low_bits );
    }
  else
    {
    Re_encode_bit( renc, &len_encoder->lm.choice1, 1 );
    if( symbol < len_low_symbols + len_mid_symbols )
      {
      Re_encode_bit( renc, &len_encoder->lm.choice2, 0 );
      Re_encode_tree( renc, len_encoder->lm.bm_mid[pos_state],
                      symbol - len_low_symbols, len_mid_bits );
      }
    else
      {
      Re_encode_bit( renc, &len_encoder->lm.choice2, 1 );
      Re_encode_tree( renc, len_encoder->lm.bm_high,
                      symbol - len_low_symbols - len_mid_symbols, len_high_bits );
      }
    }
  if( --len_encoder->counters[pos_state] <= 0 )
    Lee_update_prices( len_encoder, pos_state );
  }


     /* End Of Stream mark => (dis == 0xFFFFFFFFU, len == min_match_len) */
static void LZe_full_flush( struct LZ_encoder * const encoder, const State state )
  {
  int i;
  const int pos_state = Mf_data_position( encoder->matchfinder ) & pos_state_mask;
  File_trailer trailer;
  Re_encode_bit( &encoder->renc, &encoder->bm_match[state][pos_state], 1 );
  Re_encode_bit( &encoder->renc, &encoder->bm_rep[state], 0 );
  LZe_encode_pair( encoder, 0xFFFFFFFFU, min_match_len, pos_state );
  Re_flush( &encoder->renc );
  Ft_set_data_crc( trailer, LZe_crc( encoder ) );
  Ft_set_data_size( trailer, Mf_data_position( encoder->matchfinder ) );
  Ft_set_member_size( trailer, Re_member_position( &encoder->renc ) + Ft_size );
  for( i = 0; i < Ft_size; ++i )
    Re_put_byte( &encoder->renc, trailer[i] );
  Re_flush_data( &encoder->renc );
  }


static void LZe_fill_align_prices( struct LZ_encoder * const encoder )
  {
  int i;
  for( i = 0; i < dis_align_size; ++i )
    encoder->align_prices[i] =
      price_symbol_reversed( encoder->bm_align, i, dis_align_bits );
  encoder->align_price_count = dis_align_size;
  }


static void LZe_fill_distance_prices( struct LZ_encoder * const encoder )
  {
  int dis, len_state;
  for( dis = start_dis_model; dis < modeled_distances; ++dis )
    {
    const int dis_slot = dis_slots[dis];
    const int direct_bits = ( dis_slot >> 1 ) - 1;
    const int base = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
    const int price =
      price_symbol_reversed( encoder->bm_dis + base - dis_slot - 1,
                             dis - base, direct_bits );
    for( len_state = 0; len_state < len_states; ++len_state )
      encoder->dis_prices[len_state][dis] = price;
    }

  for( len_state = 0; len_state < len_states; ++len_state )
    {
    int * const dsp = encoder->dis_slot_prices[len_state];
    int * const dp = encoder->dis_prices[len_state];
    const Bit_model * const bmds = encoder->bm_dis_slot[len_state];
    int slot = 0;
    for( ; slot < end_dis_model && slot < encoder->num_dis_slots; ++slot )
      dsp[slot] = price_symbol( bmds, slot, dis_slot_bits );
    for( ; slot < encoder->num_dis_slots; ++slot )
      dsp[slot] = price_symbol( bmds, slot, dis_slot_bits ) +
                  (((( slot >> 1 ) - 1 ) - dis_align_bits ) << price_shift_bits );

    for( dis = 0; dis < start_dis_model; ++dis )
      dp[dis] = dsp[dis];
    for( ; dis < modeled_distances; ++dis )
      dp[dis] += dsp[dis_slots[dis]];
    }
  }


bool LZe_init( struct LZ_encoder * const encoder,
               struct Matchfinder * const mf,
               const File_header header, const int outfd )
  {
  int i;
  encoder->pending_num_pairs = 0;
  encoder->crc = 0xFFFFFFFFU;

  Bm_array_init( encoder->bm_literal[0], (1 << literal_context_bits) * 0x300 );
  Bm_array_init( encoder->bm_match[0], states * pos_states );
  Bm_array_init( encoder->bm_rep, states );
  Bm_array_init( encoder->bm_rep0, states );
  Bm_array_init( encoder->bm_rep1, states );
  Bm_array_init( encoder->bm_rep2, states );
  Bm_array_init( encoder->bm_len[0], states * pos_states );
  Bm_array_init( encoder->bm_dis_slot[0], len_states * (1 << dis_slot_bits) );
  Bm_array_init( encoder->bm_dis, modeled_distances - end_dis_model );
  Bm_array_init( encoder->bm_align, dis_align_size );

  encoder->matchfinder = mf;
  if( !Re_init( &encoder->renc, outfd ) ) return false;
  Lee_init( &encoder->match_len_encoder, encoder->matchfinder->match_len_limit );
  Lee_init( &encoder->rep_len_encoder, encoder->matchfinder->match_len_limit );
  encoder->num_dis_slots =
    2 * real_bits( encoder->matchfinder->dictionary_size - 1 );

  encoder->align_price_count = 0;

  for( i = 0; i < Fh_size; ++i )
    Re_put_byte( &encoder->renc, header[i] );
  return true;
  }


/* Return value == number of bytes advanced (ahead).
   trials[0]..trials[ahead-1] contain the steps to encode.
   ( trials[0].dis == -1 && trials[0].price == 1 ) means literal.
*/
static int LZe_sequence_optimizer( struct LZ_encoder * const encoder,
                                   const int reps[num_rep_distances],
                                   const State state )
  {
  int main_len, num_pairs, i, rep, cur = 0, num_trials, len;
  int replens[num_rep_distances];
  int rep_index = 0;

  if( encoder->pending_num_pairs > 0 )		/* from previous call */
    {
    num_pairs = encoder->pending_num_pairs;
    encoder->pending_num_pairs = 0;
    }
  else
    num_pairs = LZe_read_match_distances( encoder );
  main_len = ( num_pairs > 0 ) ? encoder->pairs[num_pairs-1].len : 0;

  for( i = 0; i < num_rep_distances; ++i )
    {
    replens[i] =
      Mf_true_match_len( encoder->matchfinder, 0, reps[i] + 1, max_match_len );
    if( replens[i] > replens[rep_index] ) rep_index = i;
    }
  if( replens[rep_index] >= encoder->matchfinder->match_len_limit )
    {
    encoder->trials[0].dis = rep_index;
    encoder->trials[0].price = replens[rep_index];
    LZe_move_pos( encoder, replens[rep_index] );
    return replens[rep_index];
    }

  if( main_len >= encoder->matchfinder->match_len_limit )
    {
    encoder->trials[0].dis = encoder->pairs[num_pairs-1].dis + num_rep_distances;
    encoder->trials[0].price = main_len;
    LZe_move_pos( encoder, main_len );
    return main_len;
    }

  {
  const int pos_state = Mf_data_position( encoder->matchfinder ) & pos_state_mask;
  const int match_price = price1( encoder->bm_match[state][pos_state] );
  const int rep_match_price = match_price + price1( encoder->bm_rep[state] );
  const uint8_t prev_byte = Mf_peek( encoder->matchfinder, -1 );
  const uint8_t cur_byte = Mf_peek( encoder->matchfinder, 0 );
  const uint8_t match_byte = Mf_peek( encoder->matchfinder, -reps[0]-1 );

  encoder->trials[0].state = state;
  encoder->trials[1].dis = -1;
  encoder->trials[1].price = price0( encoder->bm_match[state][pos_state] );
  if( St_is_char( state ) )
    encoder->trials[1].price +=
      LZe_price_literal( encoder, prev_byte, cur_byte );
  else
    encoder->trials[1].price +=
      LZe_price_matched( encoder, prev_byte, cur_byte, match_byte );

  if( match_byte == cur_byte )
    Tr_update( &encoder->trials[1], rep_match_price +
               LZe_price_rep_len1( encoder, state, pos_state ), 0, 0 );

  num_trials = max( main_len, replens[rep_index] );

  if( num_trials < min_match_len )
    {
    encoder->trials[0].dis = encoder->trials[1].dis;
    encoder->trials[0].price = 1;
    Mf_move_pos( encoder->matchfinder );
    return 1;
    }

  for( i = 0; i < num_rep_distances; ++i )
    encoder->trials[0].reps[i] = reps[i];
  encoder->trials[1].prev_index = 0;
  encoder->trials[1].prev_index2 = single_step_trial;

  for( len = min_match_len; len <= num_trials; ++len )
    encoder->trials[len].price = infinite_price;

  for( rep = 0; rep < num_rep_distances; ++rep )
    {
    int price;
    if( replens[rep] < min_match_len ) continue;
    price = rep_match_price + LZe_price_rep( encoder, rep, state, pos_state );

    for( len = min_match_len; len <= replens[rep]; ++len )
      Tr_update( &encoder->trials[len], price +
                 Lee_price( &encoder->rep_len_encoder, len, pos_state ),
                 rep, 0 );
    }

  if( main_len > replens[0] )
    {
    const int normal_match_price = match_price + price0( encoder->bm_rep[state] );
    i = 0, len = max( replens[0] + 1, min_match_len );
    while( len > encoder->pairs[i].len ) ++i;
    while( true )
      {
      const int dis = encoder->pairs[i].dis;
      Tr_update( &encoder->trials[len], normal_match_price +
                 LZe_price_pair( encoder, dis, len, pos_state ),
                 dis + num_rep_distances, 0 );
      if( ++len > encoder->pairs[i].len && ++i >= num_pairs ) break;
      }
    }
  }

  Mf_move_pos( encoder->matchfinder );

  while( true )				/* price optimization loop */
    {
    struct Trial *cur_trial, *next_trial;
    int newlen, pos_state, prev_index, prev_index2, available_bytes, len_limit;
    int start_len = min_match_len;
    int next_price, match_price, rep_match_price;
    State cur_state;
    uint8_t prev_byte, cur_byte, match_byte;

    if( ++cur >= num_trials )		/* no more initialized trials */
      {
      LZe_backward( encoder, cur );
      return cur;
      }

    num_pairs = LZe_read_match_distances( encoder );
    newlen = ( num_pairs > 0 ) ? encoder->pairs[num_pairs-1].len : 0;
    if( newlen >= encoder->matchfinder->match_len_limit )
      {
      encoder->pending_num_pairs = num_pairs;
      LZe_backward( encoder, cur );
      return cur;
      }

    /* give final values to current trial */
    cur_trial = &encoder->trials[cur];
    prev_index = cur_trial->prev_index;
    prev_index2 = cur_trial->prev_index2;

    if( prev_index2 != single_step_trial )
      {
      --prev_index;
      if( prev_index2 >= 0 )
        {
        cur_state = encoder->trials[prev_index2].state;
        if( cur_trial->dis2 < num_rep_distances )
          cur_state = St_set_rep( cur_state );
        else
          cur_state = St_set_match( cur_state );
        }
      else
        cur_state = encoder->trials[prev_index].state;
      cur_state = St_set_char( cur_state );
      }
    else
      cur_state = encoder->trials[prev_index].state;

    if( prev_index == cur - 1 )
      {
      if( cur_trial->dis == 0 )
        cur_state = St_set_short_rep( cur_state );
      else
        cur_state = St_set_char( cur_state );
      for( i = 0; i < num_rep_distances; ++i )
        cur_trial->reps[i] = encoder->trials[prev_index].reps[i];
      }
    else
      {
      int dis;
      if( prev_index2 >= 0 )
        {
        dis = cur_trial->dis2;
        prev_index = prev_index2;
        cur_state = St_set_rep( cur_state );
        }
      else
        {
        dis = cur_trial->dis;
        if( dis < num_rep_distances )
          cur_state = St_set_rep( cur_state );
        else
          cur_state = St_set_match( cur_state );
        }
      for( i = 0; i < num_rep_distances; ++i )
        cur_trial->reps[i] = encoder->trials[prev_index].reps[i];
      LZe_mtf_reps( dis, cur_trial->reps );
      }
    cur_trial->state = cur_state;

    pos_state = Mf_data_position( encoder->matchfinder ) & pos_state_mask;
    prev_byte = Mf_peek( encoder->matchfinder, -1 );
    cur_byte = Mf_peek( encoder->matchfinder, 0 );
    match_byte = Mf_peek( encoder->matchfinder, -cur_trial->reps[0]-1 );

    next_price = cur_trial->price +
                 price0( encoder->bm_match[cur_state][pos_state] );
    if( St_is_char( cur_state ) )
      next_price += LZe_price_literal( encoder, prev_byte, cur_byte );
    else
      next_price += LZe_price_matched( encoder, prev_byte, cur_byte, match_byte );
    Mf_move_pos( encoder->matchfinder );

    /* try last updates to next trial */
    next_trial = &encoder->trials[cur+1];

    Tr_update( next_trial, next_price, -1, cur );

    match_price = cur_trial->price + price1( encoder->bm_match[cur_state][pos_state] );
    rep_match_price = match_price + price1( encoder->bm_rep[cur_state] );

    if( match_byte == cur_byte && next_trial->dis != 0 )
      {
      const int price = rep_match_price +
                        LZe_price_rep_len1( encoder, cur_state, pos_state );
      if( price <= next_trial->price )
        {
        next_trial->price = price;
        next_trial->dis = 0;
        next_trial->prev_index = cur;
        next_trial->prev_index2 = single_step_trial;
        }
      }

    available_bytes = min( Mf_available_bytes( encoder->matchfinder ) + 1,
                           max_num_trials - 1 - cur );
    if( available_bytes < min_match_len ) continue;

    len_limit = min( encoder->matchfinder->match_len_limit, available_bytes );

    /* try literal + rep0 */
    if( match_byte != cur_byte && next_trial->prev_index != cur )
      {
      const uint8_t * const data = Mf_ptr_to_current_pos( encoder->matchfinder ) - 1;
      const int dis = cur_trial->reps[0] + 1;
      const int limit = min( encoder->matchfinder->match_len_limit + 1,
                             available_bytes );
      len = 1;
      while( len < limit && data[len-dis] == data[len] ) ++len;
      if( --len >= min_match_len )
        {
        const int pos_state2 = ( pos_state + 1 ) & pos_state_mask;
        const State state2 = St_set_char( cur_state );
        const int price = next_price +
                  price1( encoder->bm_match[state2][pos_state2] ) +
                  price1( encoder->bm_rep[state2] ) +
                  LZe_price_rep0_len( encoder, len, state2, pos_state2 );
        while( num_trials < cur + 1 + len )
          encoder->trials[++num_trials].price = infinite_price;
        Tr_update2( &encoder->trials[cur+1+len], price, 0, cur + 1 );
        }
      }

    /* try rep distances */
    for( rep = 0; rep < num_rep_distances; ++rep )
      {
      const uint8_t * const data = Mf_ptr_to_current_pos( encoder->matchfinder ) - 1;
      int price;
      const int dis = cur_trial->reps[rep] + 1;

      if( data[-dis] != data[0] || data[1-dis] != data[1] ) continue;
      for( len = min_match_len; len < len_limit; ++len )
        if( data[len-dis] != data[len] ) break;
      while( num_trials < cur + len )
        encoder->trials[++num_trials].price = infinite_price;
      price = rep_match_price +
              LZe_price_rep( encoder, rep, cur_state, pos_state );
      for( i = min_match_len; i <= len; ++i )
        Tr_update( &encoder->trials[cur+i], price +
                   Lee_price( &encoder->rep_len_encoder, i, pos_state ),
                   rep, cur );

      if( rep == 0 ) start_len = len + 1;	/* discard shorter matches */

      /* try rep + literal + rep0 */
      {
      int len2 = len + 1, pos_state2;
      const int limit = min( encoder->matchfinder->match_len_limit + len2,
                             available_bytes );
      State state2;
      while( len2 < limit && data[len2-dis] == data[len2] ) ++len2;
      len2 -= len + 1;
      if( len2 < min_match_len ) continue;

      pos_state2 = ( pos_state + len ) & pos_state_mask;
      state2 = St_set_rep( cur_state );
      price += Lee_price( &encoder->rep_len_encoder, len, pos_state ) +
               price0( encoder->bm_match[state2][pos_state2] ) +
               LZe_price_matched( encoder, data[len-1], data[len], data[len-dis] );
      pos_state2 = ( pos_state2 + 1 ) & pos_state_mask;
      state2 = St_set_char( state2 );
      price += price1( encoder->bm_match[state2][pos_state2] ) +
               price1( encoder->bm_rep[state2] ) +
               LZe_price_rep0_len( encoder, len2, state2, pos_state2 );
      while( num_trials < cur + len + 1 + len2 )
        encoder->trials[++num_trials].price = infinite_price;
      Tr_update3( &encoder->trials[cur+len+1+len2], price, 0, cur + len + 1,
                  rep, cur );
      }
      }

    /* try matches */
    if( newlen >= start_len && newlen <= len_limit )
      {
      int dis;
      const int normal_match_price = match_price +
                                     price0( encoder->bm_rep[cur_state] );

      while( num_trials < cur + newlen )
        encoder->trials[++num_trials].price = infinite_price;

      i = 0;
      while( start_len > encoder->pairs[i].len ) ++i;
      dis = encoder->pairs[i].dis;
      for( len = start_len; ; ++len )
        {
        int price = normal_match_price +
                    LZe_price_pair( encoder, dis, len, pos_state );

        Tr_update( &encoder->trials[cur+len], price, dis + num_rep_distances, cur );

        /* try match + literal + rep0 */
        if( len == encoder->pairs[i].len )
          {
          const uint8_t * const data = Mf_ptr_to_current_pos( encoder->matchfinder ) - 1;
          const int dis2 = dis + 1;
          int len2 = len + 1;
          const int limit = min( encoder->matchfinder->match_len_limit + len2,
                                 available_bytes );
          while( len2 < limit && data[len2-dis2] == data[len2] ) ++len2;
          len2 -= len + 1;
          if( len2 >= min_match_len )
            {
            int pos_state2 = ( pos_state + len ) & pos_state_mask;
            State state2 = St_set_match( cur_state );
            price += price0( encoder->bm_match[state2][pos_state2] ) +
                     LZe_price_matched( encoder, data[len-1], data[len], data[len-dis2] );
            pos_state2 = ( pos_state2 + 1 ) & pos_state_mask;
            state2 = St_set_char( state2 );
            price += price1( encoder->bm_match[state2][pos_state2] ) +
                     price1( encoder->bm_rep[state2] ) +
                     LZe_price_rep0_len( encoder, len2, state2, pos_state2 );

            while( num_trials < cur + len + 1 + len2 )
              encoder->trials[++num_trials].price = infinite_price;
            Tr_update3( &encoder->trials[cur+len+1+len2], price, 0,
                        cur + len + 1, dis + num_rep_distances, cur );
            }
          if( ++i >= num_pairs ) break;
          dis = encoder->pairs[i].dis;
          }
        }
      }
    }
  }


bool LZe_encode_member( struct LZ_encoder * const encoder,
                        const unsigned long long member_size )
  {
  const unsigned long long member_size_limit =
    member_size - Ft_size - max_marker_size;
  const int fill_count =
    ( encoder->matchfinder->match_len_limit > 12 ) ? 128 : 512;
  int fill_counter = 0;
  int ahead, i;
  int rep_distances[num_rep_distances];
  State state = 0;
  for( i = 0; i < num_rep_distances; ++i ) rep_distances[i] = 0;

  if( Mf_data_position( encoder->matchfinder ) != 0 ||
      Re_member_position( &encoder->renc ) != Fh_size )
    return false;			/* can be called only once */

  if( !Mf_finished( encoder->matchfinder ) )	/* encode first byte */
    {
    const uint8_t prev_byte = 0;
    const uint8_t cur_byte = Mf_peek( encoder->matchfinder, 0 );
    Re_encode_bit( &encoder->renc, &encoder->bm_match[state][0], 0 );
    LZe_encode_literal( encoder, prev_byte, cur_byte );
    CRC32_update_byte( &encoder->crc, cur_byte );
    Mf_get_match_pairs( encoder->matchfinder, 0 );
    Mf_move_pos( encoder->matchfinder );
    }

  while( !Mf_finished( encoder->matchfinder ) )
    {
    if( encoder->pending_num_pairs == 0 )
      {
      if( fill_counter <= 0 )
        { LZe_fill_distance_prices( encoder ); fill_counter = fill_count; }
      if( encoder->align_price_count <= 0 )
        LZe_fill_align_prices( encoder );
      }

    ahead = LZe_sequence_optimizer( encoder, rep_distances, state );
    if( ahead <= 0 ) return false;		/* can't happen */

    for( i = 0; ; )
      {
      const int pos_state =
        ( Mf_data_position( encoder->matchfinder ) - ahead ) & pos_state_mask;
      const int dis = encoder->trials[i].dis;
      const int len = encoder->trials[i].price;

      bool bit = ( dis < 0 && len == 1 );
      Re_encode_bit( &encoder->renc,
                     &encoder->bm_match[state][pos_state], !bit );
      if( bit )					/* literal byte */
        {
        const uint8_t prev_byte = Mf_peek( encoder->matchfinder, -ahead-1 );
        const uint8_t cur_byte = Mf_peek( encoder->matchfinder, -ahead );
        CRC32_update_byte( &encoder->crc, cur_byte );
        if( St_is_char( state ) )
          LZe_encode_literal( encoder, prev_byte, cur_byte );
        else
          {
          const uint8_t match_byte =
            Mf_peek( encoder->matchfinder, -ahead-rep_distances[0]-1 );
          LZe_encode_matched( encoder, prev_byte, cur_byte, match_byte );
          }
        state = St_set_char( state );
        }
      else					/* match or repeated match */
        {
        CRC32_update_buf( &encoder->crc, Mf_ptr_to_current_pos( encoder->matchfinder ) - ahead, len );
        LZe_mtf_reps( dis, rep_distances );
        bit = ( dis < num_rep_distances );
        Re_encode_bit( &encoder->renc, &encoder->bm_rep[state], bit );
        if( bit )
          {
          bit = ( dis == 0 );
          Re_encode_bit( &encoder->renc, &encoder->bm_rep0[state], !bit );
          if( bit )
            Re_encode_bit( &encoder->renc, &encoder->bm_len[state][pos_state], len > 1 );
          else
            {
            Re_encode_bit( &encoder->renc, &encoder->bm_rep1[state], dis > 1 );
            if( dis > 1 )
              Re_encode_bit( &encoder->renc, &encoder->bm_rep2[state], dis > 2 );
            }
          if( len == 1 ) state = St_set_short_rep( state );
          else
            {
            Lee_encode( &encoder->rep_len_encoder, &encoder->renc, len, pos_state );
            state = St_set_rep( state );
            }
          }
        else
          {
          LZe_encode_pair( encoder, dis - num_rep_distances, len, pos_state );
          --fill_counter;
          state = St_set_match( state );
          }
        }
      ahead -= len; i += len;
      if( Re_member_position( &encoder->renc ) >= member_size_limit )
        {
        if( !Mf_dec_pos( encoder->matchfinder, ahead ) ) return false;
        LZe_full_flush( encoder, state );
        return true;
        }
      if( ahead <= 0 ) break;
      }
    }
  LZe_full_flush( encoder, state );
  return true;
  }