diff options
Diffstat (limited to 'fast_encoder.c')
| -rw-r--r-- | fast_encoder.c | 44 |
1 files changed, 18 insertions, 26 deletions
diff --git a/fast_encoder.c b/fast_encoder.c index 941c0e2..399cc1a 100644 --- a/fast_encoder.c +++ b/fast_encoder.c @@ -1,5 +1,5 @@ /* Clzip - LZMA lossless data compressor - Copyright (C) 2010-2016 Antonio Diaz Diaz. + 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 @@ -33,21 +33,22 @@ int FLZe_longest_match_len( struct FLZ_encoder * const fe, int * const distance enum { len_limit = 16 }; const uint8_t * const data = Mb_ptr_to_current_pos( &fe->eb.mb ); int32_t * ptr0 = fe->eb.mb.pos_array + fe->eb.mb.cyclic_pos; - int32_t * newptr; const int pos1 = fe->eb.mb.pos + 1; - int maxlen = 0; - int count, delta, newpos; - if( len_limit > Mb_available_bytes( &fe->eb.mb ) ) return 0; + int maxlen = 0, newpos1, count; + const int available = min( Mb_available_bytes( &fe->eb.mb ), max_match_len ); + if( available < len_limit ) return 0; fe->key4 = ( ( fe->key4 << 4 ) ^ data[3] ) & fe->eb.mb.key4_mask; - newpos = fe->eb.mb.prev_positions[fe->key4]; + newpos1 = fe->eb.mb.prev_positions[fe->key4]; fe->eb.mb.prev_positions[fe->key4] = pos1; for( count = 4; ; ) { - if( --count < 0 || newpos <= 0 ) { *ptr0 = 0; break; } - delta = pos1 - newpos; - if( delta > fe->eb.mb.dictionary_size ) { *ptr0 = 0; break; } + int32_t * newptr; + int delta; + if( newpos1 <= 0 || --count < 0 || + ( delta = pos1 - newpos1 ) > fe->eb.mb.dictionary_size ) + { *ptr0 = 0; break; } newptr = fe->eb.mb.pos_array + ( fe->eb.mb.cyclic_pos - delta + ( ( fe->eb.mb.cyclic_pos >= delta ) ? 0 : fe->eb.mb.dictionary_size + 1 ) ); @@ -55,23 +56,15 @@ int FLZe_longest_match_len( struct FLZ_encoder * const fe, 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 += Mb_true_match_len( &fe->eb.mb, maxlen, *distance + 1, - max_match_len - maxlen ); - break; - } + *ptr0 = newpos1; + ptr0 = newptr; + newpos1 = *ptr0; } return maxlen; } @@ -112,8 +105,7 @@ bool FLZe_encode_member( struct FLZ_encoder * const fe, for( i = 0; i < num_rep_distances; ++i ) { - const int tlen = Mb_true_match_len( &fe->eb.mb, 0, - reps[i] + 1, max_match_len ); + const int tlen = Mb_true_match_len( &fe->eb.mb, 0, reps[i] + 1 ); if( tlen > len ) { len = tlen; rep = i; } } if( len > min_match_len && len + 3 > main_len ) |