diff options
Diffstat (limited to 'fast_encoder.c')
| -rw-r--r-- | fast_encoder.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/fast_encoder.c b/fast_encoder.c new file mode 100644 index 0000000..bab87ca --- /dev/null +++ b/fast_encoder.c @@ -0,0 +1,186 @@ +/* Clzip - LZMA lossless data compressor + Copyright (C) 2010-2024 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/>. +*/ + +#define _FILE_OFFSET_BITS 64 + +#include <errno.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> + +#include "lzip.h" +#include "encoder_base.h" +#include "fast_encoder.h" + + +int FLZe_longest_match_len( struct FLZ_encoder * const fe, int * const distance ) + { + enum { len_limit = 16 }; + const int available = min( Mb_available_bytes( &fe->eb.mb ), max_match_len ); + if( available < len_limit ) return 0; + + const uint8_t * const data = Mb_ptr_to_current_pos( &fe->eb.mb ); + fe->key4 = ( ( fe->key4 << 4 ) ^ data[3] ) & fe->eb.mb.key4_mask; + const int pos1 = fe->eb.mb.pos + 1; + int newpos1 = fe->eb.mb.prev_positions[fe->key4]; + fe->eb.mb.prev_positions[fe->key4] = pos1; + int32_t * ptr0 = fe->eb.mb.pos_array + fe->eb.mb.cyclic_pos; + int maxlen = 0, count; + + for( count = 4; ; ) + { + int delta; + if( newpos1 <= 0 || --count < 0 || + ( delta = pos1 - newpos1 ) > fe->eb.mb.dictionary_size ) + { *ptr0 = 0; break; } + int32_t * const 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 ) ); + + if( data[maxlen-delta] == data[maxlen] ) + { + int len = 0; + while( len < available && data[len-delta] == data[len] ) ++len; + if( maxlen < len ) + { maxlen = len; *distance = delta - 1; + if( maxlen >= len_limit ) { *ptr0 = *newptr; break; } } + } + + *ptr0 = newpos1; + ptr0 = newptr; + newpos1 = *ptr0; + } + return maxlen; + } + + +bool FLZe_encode_member( struct FLZ_encoder * const fe, + const unsigned long long member_size ) + { + const unsigned long long member_size_limit = + member_size - Lt_size - max_marker_size; + int rep = 0, i; + int reps[num_rep_distances]; + State state = 0; + for( i = 0; i < num_rep_distances; ++i ) reps[i] = 0; + + if( Mb_data_position( &fe->eb.mb ) != 0 || + Re_member_position( &fe->eb.renc ) != Lh_size ) + return false; /* can be called only once */ + + if( !Mb_data_finished( &fe->eb.mb ) ) /* encode first byte */ + { + const uint8_t prev_byte = 0; + const uint8_t cur_byte = Mb_peek( &fe->eb.mb, 0 ); + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[state][0], 0 ); + LZeb_encode_literal( &fe->eb, prev_byte, cur_byte ); + CRC32_update_byte( &fe->eb.crc, cur_byte ); + FLZe_reset_key4( fe ); + FLZe_update_and_move( fe, 1 ); + } + + while( !Mb_data_finished( &fe->eb.mb ) && + Re_member_position( &fe->eb.renc ) < member_size_limit ) + { + int match_distance; + const int main_len = FLZe_longest_match_len( fe, &match_distance ); + const int pos_state = Mb_data_position( &fe->eb.mb ) & pos_state_mask; + int len = 0; + + for( i = 0; i < num_rep_distances; ++i ) + { + 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 ) + { + CRC32_update_buf( &fe->eb.crc, Mb_ptr_to_current_pos( &fe->eb.mb ), len ); + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[state][pos_state], 1 ); + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep[state], 1 ); + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep0[state], rep != 0 ); + if( rep == 0 ) + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_len[state][pos_state], 1 ); + else + { + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep1[state], rep > 1 ); + if( rep > 1 ) + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep2[state], rep > 2 ); + const int distance = reps[rep]; + for( i = rep; i > 0; --i ) reps[i] = reps[i-1]; + reps[0] = distance; + } + state = St_set_rep( state ); + Re_encode_len( &fe->eb.renc, &fe->eb.rep_len_model, len, pos_state ); + Mb_move_pos( &fe->eb.mb ); + FLZe_update_and_move( fe, len - 1 ); + continue; + } + + if( main_len > min_match_len ) + { + CRC32_update_buf( &fe->eb.crc, Mb_ptr_to_current_pos( &fe->eb.mb ), main_len ); + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[state][pos_state], 1 ); + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep[state], 0 ); + state = St_set_match( state ); + for( i = num_rep_distances - 1; i > 0; --i ) reps[i] = reps[i-1]; + reps[0] = match_distance; + LZeb_encode_pair( &fe->eb, match_distance, main_len, pos_state ); + Mb_move_pos( &fe->eb.mb ); + FLZe_update_and_move( fe, main_len - 1 ); + continue; + } + + const uint8_t prev_byte = Mb_peek( &fe->eb.mb, 1 ); + const uint8_t cur_byte = Mb_peek( &fe->eb.mb, 0 ); + const uint8_t match_byte = Mb_peek( &fe->eb.mb, reps[0] + 1 ); + Mb_move_pos( &fe->eb.mb ); + CRC32_update_byte( &fe->eb.crc, cur_byte ); + + if( match_byte == cur_byte ) + { + const int short_rep_price = price1( fe->eb.bm_match[state][pos_state] ) + + price1( fe->eb.bm_rep[state] ) + + price0( fe->eb.bm_rep0[state] ) + + price0( fe->eb.bm_len[state][pos_state] ); + int price = price0( fe->eb.bm_match[state][pos_state] ); + if( St_is_char( state ) ) + price += LZeb_price_literal( &fe->eb, prev_byte, cur_byte ); + else + price += LZeb_price_matched( &fe->eb, prev_byte, cur_byte, match_byte ); + if( short_rep_price < price ) + { + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[state][pos_state], 1 ); + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep[state], 1 ); + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep0[state], 0 ); + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_len[state][pos_state], 0 ); + state = St_set_short_rep( state ); + continue; + } + } + + /* literal byte */ + Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[state][pos_state], 0 ); + if( ( state = St_set_char( state ) ) < 4 ) + LZeb_encode_literal( &fe->eb, prev_byte, cur_byte ); + else + LZeb_encode_matched( &fe->eb, prev_byte, cur_byte, match_byte ); + } + + LZeb_full_flush( &fe->eb, state ); + return true; + } |