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-rw-r--r--fast_encoder.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/fast_encoder.c b/fast_encoder.c
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--- /dev/null
+++ b/fast_encoder.c
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+/* Clzip - LZMA lossless data compressor
+ Copyright (C) 2010-2015 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 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;
+
+ fe->key4 = ( ( fe->key4 << 4 ) ^ data[3] ) & fe->eb.mb.key4_mask;
+ newpos = 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; }
+ 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 < len_limit && data[len-delta] == data[len] ) ++len;
+ if( maxlen < len ) { maxlen = len; *distance = delta - 1; }
+ }
+
+ 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;
+ }
+ }
+ 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 - Ft_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 ) != Fh_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, max_match_len );
+ 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
+ {
+ int distance;
+ 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 );
+ 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( St_is_char( state ) )
+ LZeb_encode_literal( &fe->eb, prev_byte, cur_byte );
+ else
+ LZeb_encode_matched( &fe->eb, prev_byte, cur_byte, match_byte );
+ state = St_set_char( state );
+ }
+ }
+
+ LZeb_full_flush( &fe->eb, state );
+ return true;
+ }
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