/*  Clzip - LZMA lossless data compressor
    Copyright (C) 2010-2017 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/>.
*/

struct FLZ_encoder
  {
  struct LZ_encoder_base eb;
  unsigned key4;			/* key made from latest 4 bytes */
  };

static inline void FLZe_reset_key4( struct FLZ_encoder * const fe )
  {
  int i;
  fe->key4 = 0;
  for( i = 0; i < 3 && i < Mb_available_bytes( &fe->eb.mb ); ++i )
    fe->key4 = ( fe->key4 << 4 ) ^ fe->eb.mb.buffer[i];
  }

int FLZe_longest_match_len( struct FLZ_encoder * const fe, int * const distance );

static inline void FLZe_update_and_move( struct FLZ_encoder * const fe, int n )
  {
  while( --n >= 0 )
    {
    if( Mb_available_bytes( &fe->eb.mb ) >= 4 )
      {
      fe->key4 = ( ( fe->key4 << 4 ) ^ fe->eb.mb.buffer[fe->eb.mb.pos+3] ) &
                 fe->eb.mb.key4_mask;
      fe->eb.mb.pos_array[fe->eb.mb.cyclic_pos] = fe->eb.mb.prev_positions[fe->key4];
      fe->eb.mb.prev_positions[fe->key4] = fe->eb.mb.pos + 1;
      }
    Mb_move_pos( &fe->eb.mb );
    }
  }

static inline bool FLZe_init( struct FLZ_encoder * const fe,
                              const int ifd, const int outfd )
  {
  enum { before = 0,
         dict_size = 65536,
         /* bytes to keep in buffer after pos */
         after_size = max_match_len,
         dict_factor = 16,
         num_prev_positions23 = 0,
         pos_array_factor = 1 };

  return LZeb_init( &fe->eb, before, dict_size, after_size, dict_factor,
                    num_prev_positions23, pos_array_factor, ifd, outfd );
  }

static inline void FLZe_reset( struct FLZ_encoder * const fe )
  { LZeb_reset( &fe->eb ); }

bool FLZe_encode_member( struct FLZ_encoder * const fe,
                         const unsigned long long member_size );
