diff options
Diffstat (limited to 'fast_encoder.cc')
| -rw-r--r-- | fast_encoder.cc | 41 |
1 files changed, 16 insertions, 25 deletions
diff --git a/fast_encoder.cc b/fast_encoder.cc index 939259f..57b21ef 100644 --- a/fast_encoder.cc +++ b/fast_encoder.cc @@ -1,5 +1,5 @@ /* Lzip - LZMA lossless data compressor - Copyright (C) 2008-2016 Antonio Diaz Diaz. + Copyright (C) 2008-2017 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 @@ -33,23 +33,22 @@ int FLZ_encoder::longest_match_len( int * const distance ) { enum { len_limit = 16 }; - if( len_limit > available_bytes() ) return 0; + const int available = std::min( available_bytes(), (int)max_match_len ); + if( available < len_limit ) return 0; const uint8_t * const data = ptr_to_current_pos(); key4 = ( ( key4 << 4 ) ^ data[3] ) & key4_mask; - const int pos1 = pos + 1; - int newpos = prev_positions[key4]; + int newpos1 = prev_positions[key4]; prev_positions[key4] = pos1; - int32_t * ptr0 = pos_array + cyclic_pos; int maxlen = 0; for( int count = 4; ; ) { - if( --count < 0 || newpos <= 0 ) { *ptr0 = 0; break; } - const int delta = pos1 - newpos; - if( delta > dictionary_size ) { *ptr0 = 0; break; } + int delta; + if( newpos1 <= 0 || --count < 0 || + ( delta = pos1 - newpos1 ) > dictionary_size ) { *ptr0 = 0; break; } int32_t * const newptr = pos_array + ( cyclic_pos - delta + ( ( cyclic_pos >= delta ) ? 0 : dictionary_size + 1 ) ); @@ -57,22 +56,15 @@ int FLZ_encoder::longest_match_len( int * const distance ) if( data[maxlen-delta] == data[maxlen] ) { int len = 0; - while( len < len_limit && data[len-delta] == data[len] ) ++len; - if( maxlen < len ) { maxlen = len; *distance = delta - 1; } + while( len < available && data[len-delta] == data[len] ) ++len; + if( maxlen < len ) + { maxlen = len; *distance = delta - 1; + if( maxlen >= len_limit ) { *ptr0 = *newptr; break; } } } - if( maxlen < len_limit ) - { - *ptr0 = newpos; - ptr0 = newptr; - newpos = *ptr0; - } - else - { - *ptr0 = *newptr; - maxlen += true_match_len( maxlen, *distance + 1, max_match_len - maxlen ); - break; - } + *ptr0 = newpos1; + ptr0 = newptr; + newpos1 = *ptr0; } return maxlen; } @@ -110,7 +102,7 @@ bool FLZ_encoder::encode_member( const unsigned long long member_size ) for( int i = 0; i < num_rep_distances; ++i ) { - const int tlen = true_match_len( 0, reps[i] + 1, max_match_len ); + const int tlen = true_match_len( 0, reps[i] + 1 ); if( tlen > len ) { len = tlen; rep = i; } } if( len > min_match_len && len + 3 > main_len ) @@ -181,11 +173,10 @@ bool FLZ_encoder::encode_member( const unsigned long long member_size ) // literal byte renc.encode_bit( bm_match[state()][pos_state], 0 ); - if( state.is_char() ) + if( state.is_char_set_char() ) encode_literal( prev_byte, cur_byte ); else encode_matched( prev_byte, cur_byte, match_byte ); - state.set_char(); } full_flush( state ); |