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authorDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 07:49:37 +0000
committerDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 07:49:37 +0000
commit867c3a558780e371ffc835ac5dc19613fb177233 (patch)
treee388646a6bb73561a4b9c864bf8d38629f1d1bcd /fast_encoder.cc
parentAdding upstream version 1.10. (diff)
downloadlzip-867c3a558780e371ffc835ac5dc19613fb177233.tar.xz
lzip-867c3a558780e371ffc835ac5dc19613fb177233.zip
Adding upstream version 1.11.upstream/1.11
Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>
Diffstat (limited to 'fast_encoder.cc')
-rw-r--r--fast_encoder.cc378
1 files changed, 378 insertions, 0 deletions
diff --git a/fast_encoder.cc b/fast_encoder.cc
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+/* Lzip - Data compressor based on the LZMA algorithm
+ Copyright (C) 2008, 2009, 2010 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 3 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.h"
+#include "fast_encoder.h"
+
+
+bool Fmatchfinder::read_block()
+ {
+ if( !at_stream_end && stream_pos < buffer_size )
+ {
+ const int size = buffer_size - stream_pos;
+ const int rd = readblock( infd, buffer + stream_pos, size );
+ stream_pos += rd;
+ if( rd != size && errno ) throw Error( "Read error" );
+ at_stream_end = ( rd < size );
+ }
+ return pos < stream_pos;
+ }
+
+
+Fmatchfinder::Fmatchfinder( const int ifd )
+ :
+ partial_data_pos( 0 ),
+ prev_positions( new int32_t[num_prev_positions] ),
+ pos( 0 ),
+ cyclic_pos( 0 ),
+ key4( 0 ),
+ stream_pos( 0 ),
+ match_len_limit_( 16 ),
+ infd( ifd ),
+ at_stream_end( false )
+ {
+ const int dict_size = 65536;
+ const int buffer_size_limit = ( 16 * dict_size ) + before_size + after_size;
+ buffer_size = dict_size;
+ buffer = (uint8_t *)std::malloc( buffer_size );
+ if( !buffer ) throw std::bad_alloc();
+ if( read_block() && !at_stream_end && buffer_size < buffer_size_limit )
+ {
+ buffer_size = buffer_size_limit;
+ buffer = (uint8_t *)std::realloc( buffer, buffer_size );
+ if( !buffer ) throw std::bad_alloc();
+ read_block();
+ }
+ if( at_stream_end && stream_pos < dict_size )
+ dictionary_size_ = std::max( (int)min_dictionary_size, stream_pos );
+ else dictionary_size_ = dict_size;
+ pos_limit = buffer_size;
+ if( !at_stream_end ) pos_limit -= after_size;
+ prev_pos_chain = new int32_t[dictionary_size_];
+ for( int i = 0; i < num_prev_positions; ++i ) prev_positions[i] = -1;
+ }
+
+
+void Fmatchfinder::reset()
+ {
+ const int size = stream_pos - pos;
+ if( size > 0 ) std::memmove( buffer, buffer + pos, size );
+ partial_data_pos = 0;
+ stream_pos -= pos;
+ pos = 0;
+ cyclic_pos = 0;
+ key4 = 0;
+ for( int i = 0; i < num_prev_positions; ++i ) prev_positions[i] = -1;
+ read_block();
+ }
+
+
+void Fmatchfinder::move_pos()
+ {
+ if( ++cyclic_pos >= dictionary_size_ ) cyclic_pos = 0;
+ if( ++pos >= pos_limit )
+ {
+ if( pos > stream_pos )
+ internal_error( "pos > stream_pos in Fmatchfinder::move_pos" );
+ if( !at_stream_end )
+ {
+ const int offset = pos - dictionary_size_ - before_size;
+ const int size = stream_pos - offset;
+ std::memmove( buffer, buffer + offset, size );
+ partial_data_pos += offset;
+ pos -= offset;
+ stream_pos -= offset;
+ for( int i = 0; i < num_prev_positions; ++i )
+ if( prev_positions[i] >= 0 ) prev_positions[i] -= offset;
+ for( int i = 0; i < dictionary_size_; ++i )
+ if( prev_pos_chain[i] >= 0 ) prev_pos_chain[i] -= offset;
+ read_block();
+ }
+ }
+ }
+
+
+int Fmatchfinder::longest_match_len( int * const distance ) throw()
+ {
+ int len_limit = match_len_limit_;
+ if( len_limit > available_bytes() )
+ {
+ len_limit = available_bytes();
+ if( len_limit < 4 ) return 0;
+ }
+
+ int maxlen = min_match_len - 1;
+ const int min_pos = (pos >= dictionary_size_) ?
+ (pos - dictionary_size_ + 1) : 0;
+ const uint8_t * const data = buffer + pos;
+ key4 = ( ( key4 << 4 ) ^ data[3] ) & ( num_prev_positions - 1 );
+
+ int newpos = prev_positions[key4];
+ prev_positions[key4] = pos;
+
+ int32_t * ptr0 = prev_pos_chain + cyclic_pos;
+
+ for( int count = 4; ; )
+ {
+ if( newpos < min_pos || --count < 0 ) { *ptr0 = -1; break; }
+ const uint8_t * const newdata = buffer + newpos;
+ int len = 0;
+ while( len < len_limit && newdata[len] == data[len] ) ++len;
+
+ const int delta = pos - newpos;
+ if( maxlen < len ) { maxlen = len; *distance = delta - 1; }
+
+ int32_t * const newptr = prev_pos_chain +
+ ( cyclic_pos - delta +
+ ( ( cyclic_pos >= delta ) ? 0 : dictionary_size_ ) );
+
+ if( len < len_limit )
+ {
+ *ptr0 = newpos;
+ ptr0 = newptr;
+ newpos = *ptr0;
+ }
+ else
+ {
+ *ptr0 = *newptr;
+ break;
+ }
+ }
+ return maxlen;
+ }
+
+
+void Fmatchfinder::longest_match_len() throw()
+ {
+ int len_limit = match_len_limit_;
+ if( len_limit > available_bytes() )
+ {
+ len_limit = available_bytes();
+ if( len_limit < 4 ) return;
+ }
+
+ const int min_pos = (pos >= dictionary_size_) ?
+ (pos - dictionary_size_ + 1) : 0;
+ const uint8_t * const data = buffer + pos;
+ key4 = ( ( key4 << 4 ) ^ data[3] ) & ( num_prev_positions - 1 );
+
+ const int newpos = prev_positions[key4];
+ prev_positions[key4] = pos;
+
+ int32_t * const ptr0 = prev_pos_chain + cyclic_pos;
+
+ if( newpos < min_pos ) *ptr0 = -1;
+ else
+ {
+ const uint8_t * const newdata = buffer + newpos;
+ if( newdata[len_limit-1] != data[len_limit-1] ||
+ std::memcmp( newdata, data, len_limit - 1 ) ) *ptr0 = newpos;
+ else
+ {
+ const int delta = pos - newpos;
+ int idx = cyclic_pos - delta;
+ if( idx < 0 ) idx += dictionary_size_;
+ *ptr0 = prev_pos_chain[idx];
+ }
+ }
+ }
+
+
+// Return value == number of bytes advanced (len).
+// *disp returns the distance to encode.
+// ( *disp == -1 && len == 1 ) means literal.
+int FLZ_encoder::sequence_optimizer( const int reps[num_rep_distances],
+ int * const disp, const State & state )
+ {
+ const int main_len = read_match_distances();
+
+ int replen = 0;
+ int rep_index = 0;
+ for( int i = 0; i < num_rep_distances; ++i )
+ {
+ const int len = fmatchfinder.true_match_len( 0, reps[i] + 1, max_match_len );
+ if( len > replen ) { replen = len; rep_index = i; }
+ }
+ if( replen > min_match_len )
+ {
+ *disp = rep_index;
+ move_pos( replen, true );
+ return replen;
+ }
+
+ if( main_len > min_match_len ||
+ ( main_len == min_match_len && match_distance < modeled_distances ) )
+ {
+ *disp = num_rep_distances + match_distance;
+ move_pos( main_len, true );
+ return main_len;
+ }
+
+ const uint8_t cur_byte = fmatchfinder[0];
+ const uint8_t match_byte = fmatchfinder[-reps[0]-1];
+
+ *disp = -1;
+ if( match_byte == cur_byte )
+ {
+ const uint8_t prev_byte = fmatchfinder[-1];
+ const int pos_state = fmatchfinder.data_position() & pos_state_mask;
+ int price = price0( bm_match[state()][pos_state] );
+ if( state.is_char() )
+ price += literal_encoder.price_symbol( prev_byte, cur_byte );
+ else
+ price += literal_encoder.price_matched( prev_byte, cur_byte, match_byte );
+ const int short_rep_price = price1( bm_match[state()][pos_state] ) +
+ price1( bm_rep[state()] ) +
+ price_rep_len1( state, pos_state );
+ if( short_rep_price < price ) *disp = 0;
+ }
+
+ fmatchfinder.move_pos();
+ return 1;
+ }
+
+
+ // End Of Stream mark => (dis == 0xFFFFFFFFU, len == min_match_len)
+void FLZ_encoder::full_flush( const State & state )
+ {
+ const int pos_state = fmatchfinder.data_position() & pos_state_mask;
+ range_encoder.encode_bit( bm_match[state()][pos_state], 1 );
+ range_encoder.encode_bit( bm_rep[state()], 0 );
+ encode_pair( 0xFFFFFFFFU, min_match_len, pos_state );
+ range_encoder.flush();
+ File_trailer trailer;
+ trailer.data_crc( crc() );
+ trailer.data_size( fmatchfinder.data_position() );
+ trailer.member_size( range_encoder.member_position() + File_trailer::size() );
+ for( int i = 0; i < File_trailer::size(); ++i )
+ range_encoder.put_byte( trailer.data[i] );
+ range_encoder.flush_data();
+ }
+
+
+FLZ_encoder::FLZ_encoder( Fmatchfinder & mf, const File_header & header,
+ const int outfd )
+ :
+ crc_( 0xFFFFFFFFU ),
+ fmatchfinder( mf ),
+ range_encoder( outfd ),
+ len_encoder( fmatchfinder.match_len_limit() ),
+ rep_match_len_encoder( fmatchfinder.match_len_limit() ),
+ num_dis_slots( 2 * real_bits( fmatchfinder.dictionary_size() - 1 ) )
+ {
+ for( int i = 0; i < File_header::size; ++i )
+ range_encoder.put_byte( header.data[i] );
+ }
+
+
+bool FLZ_encoder::encode_member( const long long member_size )
+ {
+ const long long member_size_limit =
+ member_size - File_trailer::size() - max_marker_size;
+ int rep_distances[num_rep_distances];
+ State state;
+ for( int i = 0; i < num_rep_distances; ++i ) rep_distances[i] = 0;
+
+ if( fmatchfinder.data_position() != 0 ||
+ range_encoder.member_position() != File_header::size )
+ return false; // can be called only once
+
+ if( !fmatchfinder.finished() ) // encode first byte
+ {
+ const uint8_t prev_byte = 0;
+ const uint8_t cur_byte = fmatchfinder[0];
+ range_encoder.encode_bit( bm_match[state()][0], 0 );
+ literal_encoder.encode( range_encoder, prev_byte, cur_byte );
+ crc32.update( crc_, cur_byte );
+ move_pos( 1 );
+ }
+
+ while( true )
+ {
+ if( fmatchfinder.finished() ) { full_flush( state ); return true; }
+
+ const int pos_state = fmatchfinder.data_position() & pos_state_mask;
+ int dis;
+ const int len = sequence_optimizer( rep_distances, &dis, state );
+ if( len <= 0 ) return false;
+
+ bool bit = ( dis < 0 && len == 1 );
+ range_encoder.encode_bit( bm_match[state()][pos_state], !bit );
+ if( bit ) // literal byte
+ {
+ const uint8_t prev_byte = fmatchfinder[-len-1];
+ const uint8_t cur_byte = fmatchfinder[-len];
+ crc32.update( crc_, cur_byte );
+ if( state.is_char() )
+ literal_encoder.encode( range_encoder, prev_byte, cur_byte );
+ else
+ {
+ const uint8_t match_byte = fmatchfinder[-len-rep_distances[0]-1];
+ literal_encoder.encode_matched( range_encoder,
+ prev_byte, cur_byte, match_byte );
+ }
+ state.set_char();
+ }
+ else // match or repeated match
+ {
+ crc32.update( crc_, fmatchfinder.ptr_to_current_pos() - len, len );
+ mtf_reps( dis, rep_distances );
+ bit = ( dis < num_rep_distances );
+ range_encoder.encode_bit( bm_rep[state()], bit );
+ if( bit )
+ {
+ bit = ( dis == 0 );
+ range_encoder.encode_bit( bm_rep0[state()], !bit );
+ if( bit )
+ range_encoder.encode_bit( bm_len[state()][pos_state], len > 1 );
+ else
+ {
+ range_encoder.encode_bit( bm_rep1[state()], dis > 1 );
+ if( dis > 1 )
+ range_encoder.encode_bit( bm_rep2[state()], dis > 2 );
+ }
+ if( len == 1 ) state.set_short_rep();
+ else
+ {
+ rep_match_len_encoder.encode( range_encoder, len, pos_state );
+ state.set_rep();
+ }
+ }
+ else
+ {
+ encode_pair( dis - num_rep_distances, len, pos_state );
+ state.set_match();
+ }
+ }
+ if( range_encoder.member_position() >= member_size_limit )
+ {
+ full_flush( state );
+ return true;
+ }
+ }
+ }