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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 14:23:32 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 14:23:32 +0000
commit74b9339658d8ea3690d32c237223e5974b601ed9 (patch)
tree98c0d79abbdcf18b8509c29bacee7e75314732e9 /fast_encoder.cc
parentInitial commit. (diff)
downloadlzip-74b9339658d8ea3690d32c237223e5974b601ed9.tar.xz
lzip-74b9339658d8ea3690d32c237223e5974b601ed9.zip
Adding upstream version 1.23.upstream/1.23upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fast_encoder.cc')
-rw-r--r--fast_encoder.cc184
1 files changed, 184 insertions, 0 deletions
diff --git a/fast_encoder.cc b/fast_encoder.cc
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+++ b/fast_encoder.cc
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+/* Lzip - LZMA lossless data compressor
+ Copyright (C) 2008-2022 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 <algorithm>
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
+#include <string>
+#include <vector>
+#include <stdint.h>
+
+#include "lzip.h"
+#include "encoder_base.h"
+#include "fast_encoder.h"
+
+
+int FLZ_encoder::longest_match_len( int * const distance )
+ {
+ enum { len_limit = 16 };
+ 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 newpos1 = prev_positions[key4];
+ prev_positions[key4] = pos1;
+ int32_t * ptr0 = pos_array + cyclic_pos;
+ int maxlen = 0;
+
+ for( int count = 4; ; )
+ {
+ 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 ) );
+
+ 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 FLZ_encoder::encode_member( const unsigned long long member_size )
+ {
+ const unsigned long long member_size_limit =
+ member_size - Lzip_trailer::size - max_marker_size;
+ int rep = 0;
+ int reps[num_rep_distances];
+ State state;
+ for( int i = 0; i < num_rep_distances; ++i ) reps[i] = 0;
+
+ if( data_position() != 0 || renc.member_position() != Lzip_header::size )
+ return false; // can be called only once
+
+ if( !data_finished() ) // encode first byte
+ {
+ const uint8_t prev_byte = 0;
+ const uint8_t cur_byte = peek( 0 );
+ renc.encode_bit( bm_match[state()][0], 0 );
+ encode_literal( prev_byte, cur_byte );
+ crc32.update_byte( crc_, cur_byte );
+ reset_key4();
+ update_and_move( 1 );
+ }
+
+ while( !data_finished() && renc.member_position() < member_size_limit )
+ {
+ int match_distance;
+ const int main_len = longest_match_len( &match_distance );
+ const int pos_state = data_position() & pos_state_mask;
+ int len = 0;
+
+ for( int i = 0; i < num_rep_distances; ++i )
+ {
+ 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 )
+ {
+ crc32.update_buf( crc_, ptr_to_current_pos(), len );
+ renc.encode_bit( bm_match[state()][pos_state], 1 );
+ renc.encode_bit( bm_rep[state()], 1 );
+ renc.encode_bit( bm_rep0[state()], rep != 0 );
+ if( rep == 0 )
+ renc.encode_bit( bm_len[state()][pos_state], 1 );
+ else
+ {
+ renc.encode_bit( bm_rep1[state()], rep > 1 );
+ if( rep > 1 )
+ renc.encode_bit( bm_rep2[state()], rep > 2 );
+ const int distance = reps[rep];
+ for( int i = rep; i > 0; --i ) reps[i] = reps[i-1];
+ reps[0] = distance;
+ }
+ state.set_rep();
+ renc.encode_len( rep_len_model, len, pos_state );
+ move_pos();
+ update_and_move( len - 1 );
+ continue;
+ }
+
+ if( main_len > min_match_len )
+ {
+ crc32.update_buf( crc_, ptr_to_current_pos(), main_len );
+ renc.encode_bit( bm_match[state()][pos_state], 1 );
+ renc.encode_bit( bm_rep[state()], 0 );
+ state.set_match();
+ for( int i = num_rep_distances - 1; i > 0; --i ) reps[i] = reps[i-1];
+ reps[0] = match_distance;
+ encode_pair( match_distance, main_len, pos_state );
+ move_pos();
+ update_and_move( main_len - 1 );
+ continue;
+ }
+
+ const uint8_t prev_byte = peek( 1 );
+ const uint8_t cur_byte = peek( 0 );
+ const uint8_t match_byte = peek( reps[0] + 1 );
+ move_pos();
+ crc32.update_byte( crc_, cur_byte );
+
+ if( match_byte == cur_byte )
+ {
+ const int short_rep_price = price1( bm_match[state()][pos_state] ) +
+ price1( bm_rep[state()] ) +
+ price0( bm_rep0[state()] ) +
+ price0( bm_len[state()][pos_state] );
+ int price = price0( bm_match[state()][pos_state] );
+ if( state.is_char() )
+ price += price_literal( prev_byte, cur_byte );
+ else
+ price += price_matched( prev_byte, cur_byte, match_byte );
+ if( short_rep_price < price )
+ {
+ renc.encode_bit( bm_match[state()][pos_state], 1 );
+ renc.encode_bit( bm_rep[state()], 1 );
+ renc.encode_bit( bm_rep0[state()], 0 );
+ renc.encode_bit( bm_len[state()][pos_state], 0 );
+ state.set_short_rep();
+ continue;
+ }
+ }
+
+ // literal byte
+ renc.encode_bit( bm_match[state()][pos_state], 0 );
+ if( state.is_char_set_char() )
+ encode_literal( prev_byte, cur_byte );
+ else
+ encode_matched( prev_byte, cur_byte, match_byte );
+ }
+
+ full_flush( state );
+ return true;
+ }