diff options
Diffstat (limited to 'fast_encoder.h')
| -rw-r--r-- | fast_encoder.h | 40 |
1 files changed, 26 insertions, 14 deletions
diff --git a/fast_encoder.h b/fast_encoder.h index 3f8125f..486f03f 100644 --- a/fast_encoder.h +++ b/fast_encoder.h @@ -1,5 +1,6 @@ /* Lzip - LZMA lossless data compressor - Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz. + Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013, 2014 + 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 @@ -22,23 +23,40 @@ class Fmatchfinder : public Matchfinder_base // bytes to keep in buffer after pos after_size = max_match_len, dict_factor = 16, - len_limit = 16, num_prev_positions23 = 0, pos_array_factor = 1 }; int key4; // key made from latest 4 bytes + void reset_key4() + { + key4 = 0; + for( int i = 0; i < 3 && i < available_bytes(); ++i ) + key4 = ( key4 << 4 ) ^ buffer[i]; + } + public: explicit Fmatchfinder( const int ifd ) : Matchfinder_base( before_size, dict_size, after_size, dict_factor, - len_limit, num_prev_positions23, pos_array_factor, ifd ), - key4( 0 ) - {} + num_prev_positions23, pos_array_factor, ifd ) + { reset_key4(); } - void reset() { Matchfinder_base::reset(); key4 = 0; } + enum { len_limit = 16 }; + void reset() { Matchfinder_base::reset(); reset_key4(); } int longest_match_len( int * const distance ); - void longest_match_len( int n ); + + void update_and_move( int n ) + { + while( --n >= 0 ) + { + key4 = ( ( key4 << 4 ) ^ buffer[pos+3] ) & key4_mask; + const int newpos = prev_positions[key4]; + prev_positions[key4] = pos + 1; + pos_array[cyclic_pos] = newpos; + move_pos(); + } + } }; @@ -46,16 +64,10 @@ class FLZ_encoder : public LZ_encoder_base { Fmatchfinder & fmatchfinder; - void move_pos( int n ) - { - if( --n >= 0 ) fmatchfinder.move_pos(); - fmatchfinder.longest_match_len( n ); - } - public: FLZ_encoder( Fmatchfinder & mf, const File_header & header, const int outfd ) : - LZ_encoder_base( header, mf.dictionary_size(), mf.match_len_limit(), outfd ), + LZ_encoder_base( header, mf.len_limit, outfd ), fmatchfinder( mf ) {} |