diff options
Diffstat (limited to 'encoder.cc')
| -rw-r--r-- | encoder.cc | 85 |
1 files changed, 37 insertions, 48 deletions
@@ -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 @@ -85,7 +85,7 @@ int LZ_encoder::get_match_pairs( Pair * pairs ) prev_positions[key2] = pos1; prev_positions[key3] = pos1; - int newpos = prev_positions[key4]; + int newpos1 = prev_positions[key4]; prev_positions[key4] = pos1; int32_t * ptr0 = pos_array + ( cyclic_pos << 1 ); @@ -94,9 +94,9 @@ int LZ_encoder::get_match_pairs( Pair * pairs ) for( int count = cycles; ; ) { - if( newpos <= min_pos || --count < 0 ) { *ptr0 = *ptr1 = 0; break; } + if( newpos1 <= min_pos || --count < 0 ) { *ptr0 = *ptr1 = 0; break; } - const int delta = pos1 - newpos; + const int delta = pos1 - newpos1; int32_t * const newptr = pos_array + ( ( cyclic_pos - delta + ( ( cyclic_pos >= delta ) ? 0 : dictionary_size + 1 ) ) << 1 ); @@ -118,16 +118,16 @@ int LZ_encoder::get_match_pairs( Pair * pairs ) } if( data[len-delta] < data[len] ) { - *ptr0 = newpos; + *ptr0 = newpos1; ptr0 = newptr + 1; - newpos = *ptr0; + newpos1 = *ptr0; len0 = len; if( len1 < len ) len = len1; } else { - *ptr1 = newpos; + *ptr1 = newpos1; ptr1 = newptr; - newpos = *ptr1; + newpos1 = *ptr1; len1 = len; if( len0 < len ) len = len0; } } @@ -142,7 +142,7 @@ void LZ_encoder::update_distance_prices() 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( bm_dis + base - dis_slot - 1, + const int price = price_symbol_reversed( bm_dis + ( base - dis_slot ), dis - base, direct_bits ); for( int len_state = 0; len_state < len_states; ++len_state ) dis_prices[len_state][dis] = price; @@ -171,7 +171,7 @@ void LZ_encoder::update_distance_prices() /* Returns the number of bytes advanced (ahead). trials[0]..trials[ahead-1] contain the steps to encode. - ( trials[0].dis == -1 ) means literal. + ( trials[0].dis4 == -1 ) means literal. A match/rep longer or equal than match_len_limit finishes the sequence. */ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], @@ -192,13 +192,13 @@ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], int rep_index = 0; for( int i = 0; i < num_rep_distances; ++i ) { - replens[i] = true_match_len( 0, reps[i] + 1, max_match_len ); + replens[i] = true_match_len( 0, reps[i] + 1 ); if( replens[i] > replens[rep_index] ) rep_index = i; } if( replens[rep_index] >= match_len_limit ) { trials[0].price = replens[rep_index]; - trials[0].dis = rep_index; + trials[0].dis4 = rep_index; move_and_update( replens[rep_index] ); return replens[rep_index]; } @@ -206,7 +206,7 @@ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], if( main_len >= match_len_limit ) { trials[0].price = main_len; - trials[0].dis = pairs[num_pairs-1].dis + num_rep_distances; + trials[0].dis4 = pairs[num_pairs-1].dis + num_rep_distances; move_and_update( main_len ); return main_len; } @@ -221,7 +221,7 @@ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], trials[1].price += price_literal( prev_byte, cur_byte ); else trials[1].price += price_matched( prev_byte, cur_byte, match_byte ); - trials[1].dis = -1; // literal + trials[1].dis4 = -1; // literal const int match_price = price1( bm_match[state()][pos_state] ); const int rep_match_price = match_price + price1( bm_rep[state()] ); @@ -234,7 +234,7 @@ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], if( num_trials < min_match_len ) { trials[0].price = 1; - trials[0].dis = trials[1].dis; + trials[0].dis4 = trials[1].dis4; move_pos(); return 1; } @@ -292,7 +292,7 @@ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], Trial & cur_trial = trials[cur]; State cur_state; { - int dis = cur_trial.dis; + const int dis4 = cur_trial.dis4; int prev_index = cur_trial.prev_index; const int prev_index2 = cur_trial.prev_index2; @@ -301,32 +301,24 @@ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], cur_state = trials[prev_index].state; if( prev_index + 1 == cur ) // len == 1 { - if( dis == 0 ) cur_state.set_short_rep(); + if( dis4 == 0 ) cur_state.set_short_rep(); else cur_state.set_char(); // literal } - else if( dis < num_rep_distances ) cur_state.set_rep(); + else if( dis4 < num_rep_distances ) cur_state.set_rep(); else cur_state.set_match(); } - else if( prev_index2 == dual_step_trial ) // dis == 0 + else { - --prev_index; - cur_state = trials[prev_index].state; - cur_state.set_char(); - cur_state.set_rep(); - } - else // if( prev_index2 >= 0 ) - { - prev_index = prev_index2; - cur_state = trials[prev_index].state; - if( dis < num_rep_distances ) cur_state.set_rep(); - else cur_state.set_match(); - cur_state.set_char(); - cur_state.set_rep(); + if( prev_index2 == dual_step_trial ) // dis4 == 0 (rep0) + --prev_index; + else // prev_index2 >= 0 + prev_index = prev_index2; + cur_state.set_char_rep(); } cur_trial.state = cur_state; for( int i = 0; i < num_rep_distances; ++i ) cur_trial.reps[i] = trials[prev_index].reps[i]; - mtf_reps( dis, cur_trial.reps ); + mtf_reps( dis4, cur_trial.reps ); // literal is ignored } const int pos_state = data_position() & pos_state_mask; @@ -349,14 +341,14 @@ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], const int match_price = cur_trial.price + price1( bm_match[cur_state()][pos_state] ); const int rep_match_price = match_price + price1( bm_rep[cur_state()] ); - if( match_byte == cur_byte && next_trial.dis != 0 && + if( match_byte == cur_byte && next_trial.dis4 != 0 && next_trial.prev_index2 == single_step_trial ) { const int price = rep_match_price + price_shortrep( cur_state, pos_state ); if( price <= next_trial.price ) { next_trial.price = price; - next_trial.dis = 0; + next_trial.dis4 = 0; // rep0 next_trial.prev_index = cur; } } @@ -380,9 +372,9 @@ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], const int pos_state2 = ( pos_state + 1 ) & pos_state_mask; State state2 = cur_state; state2.set_char(); const int price = next_price + - price1( bm_match[state2()][pos_state2] ) + - price1( bm_rep[state2()] ) + - price_rep0_len( len, state2, pos_state2 ); + price1( bm_match[state2()][pos_state2] ) + + price1( bm_rep[state2()] ) + + price_rep0_len( len, state2, pos_state2 ); while( num_trials < cur + 1 + len ) trials[++num_trials].price = infinite_price; trials[cur+1+len].update2( price, cur + 1 ); @@ -395,8 +387,8 @@ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], for( int rep = 0; rep < num_rep_distances; ++rep ) { const uint8_t * const data = ptr_to_current_pos(); - int len; const int dis = cur_trial.reps[rep] + 1; + int len; if( data[0-dis] != data[0] || data[1-dis] != data[1] ) continue; for( len = min_match_len; len < len_limit; ++len ) @@ -447,7 +439,6 @@ int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], for( int len = start_len; ; ++len ) { int price = normal_match_price + price_pair( dis, len, pos_state ); - trials[cur+len].update( price, dis + num_rep_distances, cur ); // try match + literal + rep0 @@ -493,7 +484,7 @@ bool LZ_encoder::encode_member( const unsigned long long member_size ) const int dis_price_count = best ? 1 : 512; const int align_price_count = best ? 1 : dis_align_size; const int price_count = ( match_len_limit > 36 ) ? 1013 : 4093; - int price_counter = 0; + int price_counter = 0; // counters may decrement below 0 int dis_price_counter = 0; int align_price_counter = 0; int reps[num_rep_distances]; @@ -532,14 +523,13 @@ bool LZ_encoder::encode_member( const unsigned long long member_size ) } int ahead = sequence_optimizer( reps, state ); - if( ahead <= 0 ) return false; // can't happen price_counter -= ahead; for( int i = 0; ahead > 0; ) { const int pos_state = ( data_position() - ahead ) & pos_state_mask; const int len = trials[i].price; - const int dis = trials[i].dis; + int dis = trials[i].dis4; bool bit = ( dis < 0 ); renc.encode_bit( bm_match[state()][pos_state], !bit ); @@ -548,14 +538,13 @@ bool LZ_encoder::encode_member( const unsigned long long member_size ) const uint8_t prev_byte = peek( ahead + 1 ); const uint8_t cur_byte = peek( ahead ); crc32.update_byte( crc_, cur_byte ); - if( state.is_char() ) + if( state.is_char_set_char() ) encode_literal( prev_byte, cur_byte ); else { const uint8_t match_byte = peek( ahead + reps[0] + 1 ); encode_matched( prev_byte, cur_byte, match_byte ); } - state.set_char(); } else // match or repeated match { @@ -585,9 +574,9 @@ bool LZ_encoder::encode_member( const unsigned long long member_size ) } else // match { - encode_pair( dis - num_rep_distances, len, pos_state ); - if( get_slot( dis - num_rep_distances ) >= end_dis_model ) - --align_price_counter; + dis -= num_rep_distances; + encode_pair( dis, len, pos_state ); + if( dis >= modeled_distances ) --align_price_counter; --dis_price_counter; match_len_prices.decrement_counter( pos_state ); state.set_match(); |