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+/* Lzip - A data compressor based on the LZMA algorithm
+ Copyright (C) 2008, 2009 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"
+
+
+Dis_slots dis_slots;
+Prob_prices prob_prices;
+
+
+bool Matchfinder::read_block() throw()
+ {
+ const int size = buffer_size - stream_pos;
+ const int rd = readblock( ides_, (char *)buffer + stream_pos, size );
+ stream_pos += rd;
+ if( rd < size ) at_stream_end = true;
+ return ( rd == size || !errno );
+ }
+
+
+bool Matchfinder::reset() throw()
+ {
+ const int size = stream_pos - pos;
+ std::memmove( buffer, buffer + pos, size );
+ partial_data_pos = 0;
+ stream_pos -= pos;
+ pos = 0;
+ cyclic_pos = 0;
+ for( int i = 0; i < num_prev_positions; ++i ) prev_positions[i] = -1;
+ return ( at_stream_end || read_block() );
+ }
+
+
+bool Matchfinder::move_pos() throw()
+ {
+ if( ++cyclic_pos >= dictionary_size_ ) cyclic_pos = 0;
+ if( ++pos >= pos_limit )
+ {
+ if( !at_stream_end )
+ {
+ const int offset = pos - dictionary_size_ - max_num_trials;
+ 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 < 2 * dictionary_size_; ++i )
+ if( prev_pos_tree[i] >= 0 ) prev_pos_tree[i] -= offset;
+ return read_block();
+ }
+ else if( pos > stream_pos ) { pos = stream_pos; return false; }
+ }
+ return true;
+ }
+
+
+int Matchfinder::longest_match_len( int * const distances ) 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;
+ const int key2 = num_prev_positions4 + num_prev_positions3 +
+ ( ( (int)data[0] << 8 ) | data[1] );
+ const int tmp = crc32[data[0]] ^ data[1] ^ ( (int)data[2] << 8 );
+ const int key3 = num_prev_positions4 + ( tmp & ( num_prev_positions3 - 1 ) );
+ const int key4 = ( tmp ^ ( crc32[data[3]] << 5 ) ) &
+ ( num_prev_positions4 - 1 );
+
+ if( distances )
+ {
+ int np = prev_positions[key2];
+ if( np >= min_pos )
+ { distances[2] = pos - np - 1; maxlen = 2; }
+ else distances[2] = 0x7FFFFFFF;
+ np = prev_positions[key3];
+ if( np >= min_pos && buffer[np] == data[0] )
+ { distances[3] = pos - np - 1; maxlen = 3; }
+ else distances[3] = 0x7FFFFFFF;
+ distances[4] = 0x7FFFFFFF;
+ }
+
+ prev_positions[key2] = pos;
+ prev_positions[key3] = pos;
+ int newpos = prev_positions[key4];
+ prev_positions[key4] = pos;
+
+ int idx0 = cyclic_pos << 1;
+ int idx1 = idx0 + 1;
+ int len0 = 0, len1 = 0;
+
+ for( int count = 16 + ( match_len_limit_ / 2 ); ; )
+ {
+ if( newpos < min_pos || --count < 0 )
+ { prev_pos_tree[idx0] = prev_pos_tree[idx1] = -1; break; }
+ const uint8_t * const newdata = buffer + newpos;
+ int len = std::min( len0, len1 );
+ while( len < len_limit && newdata[len] == data[len] ) ++len;
+
+ const int delta = pos - newpos;
+ if( distances ) while( maxlen < len ) distances[++maxlen] = delta - 1;
+
+ const int newidx = ( cyclic_pos - delta +
+ ( ( cyclic_pos >= delta ) ? 0 : dictionary_size_ ) ) << 1;
+
+ if( len < len_limit )
+ {
+ if( newdata[len] < data[len] )
+ {
+ prev_pos_tree[idx0] = newpos;
+ idx0 = newidx + 1;
+ newpos = prev_pos_tree[idx0];
+ len0 = len;
+ }
+ else
+ {
+ prev_pos_tree[idx1] = newpos;
+ idx1 = newidx;
+ newpos = prev_pos_tree[idx1];
+ len1 = len;
+ }
+ }
+ else
+ {
+ prev_pos_tree[idx0] = prev_pos_tree[newidx];
+ prev_pos_tree[idx1] = prev_pos_tree[newidx+1];
+ break;
+ }
+ }
+ if( distances )
+ {
+ if( distances[3] > distances[4] ) distances[3] = distances[4];
+ if( distances[2] > distances[3] ) distances[2] = distances[3];
+ }
+ return maxlen;
+ }
+
+
+void Len_encoder::encode( Range_encoder & range_encoder, int symbol,
+ const int pos_state )
+ {
+ symbol -= min_match_len;
+ if( symbol < len_low_symbols )
+ {
+ range_encoder.encode_bit( choice1, 0 );
+ range_encoder.encode_tree( bm_low[pos_state], symbol, len_low_bits );
+ }
+ else
+ {
+ range_encoder.encode_bit( choice1, 1 );
+ if( symbol < len_low_symbols + len_mid_symbols )
+ {
+ range_encoder.encode_bit( choice2, 0 );
+ range_encoder.encode_tree( bm_mid[pos_state], symbol - len_low_symbols, len_mid_bits );
+ }
+ else
+ {
+ range_encoder.encode_bit( choice2, 1 );
+ range_encoder.encode_tree( bm_high, symbol - len_low_symbols - len_mid_symbols, len_high_bits );
+ }
+ }
+ if( --counters[pos_state] <= 0 ) update_prices( pos_state );
+ }
+
+
+void LZ_encoder::fill_align_prices() throw()
+ {
+ for( int i = 0; i < dis_align_size; ++i )
+ align_prices[i] = price_symbol_reversed( bm_align, i, dis_align_bits );
+ align_price_count = dis_align_size;
+ }
+
+
+void LZ_encoder::fill_distance_prices() throw()
+ {
+ for( int dis_state = 0; dis_state < max_dis_states; ++dis_state )
+ {
+ int * dsp = dis_slot_prices[dis_state];
+ const Bit_model * bmds = bm_dis_slot[dis_state];
+ int slot = 0;
+ for( ; slot < end_dis_model && slot < num_dis_slots; ++slot )
+ dsp[slot] = price_symbol( bmds, slot, dis_slot_bits );
+ for( ; slot < num_dis_slots; ++slot )
+ dsp[slot] = price_symbol( bmds, slot, dis_slot_bits ) +
+ (((( slot >> 1 ) - 1 ) - dis_align_bits ) << price_shift );
+
+ int * dp = dis_prices[dis_state];
+ int dis = 0;
+ for( ; dis < start_dis_model; ++dis )
+ dp[dis] = dsp[dis];
+ for( ; dis < modeled_distances; ++dis )
+ {
+ const int dis_slot = dis_slots[dis];
+ const int direct_bits = ( dis_slot >> 1 ) - 1;
+ const int base = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
+ dp[dis] = dsp[dis_slot] +
+ price_symbol_reversed( bm_dis + base - dis_slot, dis - base, direct_bits );
+ }
+ }
+ }
+
+
+// Return value: ( dis == -1 ) && ( len == 1 ) means literal
+int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances],
+ const State & state )
+ {
+ int main_len;
+ if( longest_match_found > 0 ) // from previous call
+ {
+ main_len = longest_match_found;
+ longest_match_found = 0;
+ }
+ else main_len = read_match_distances();
+
+ int replens[num_rep_distances];
+ int rep_index = 0;
+ for( int i = 0; i < num_rep_distances; ++i )
+ {
+ replens[i] = matchfinder.true_match_len( 0, reps[i] + 1, max_match_len );
+ if( replens[i] > replens[rep_index] ) rep_index = i;
+ }
+ if( replens[rep_index] >= matchfinder.match_len_limit() )
+ {
+ trials[0].dis = rep_index;
+ trials[0].price = replens[rep_index];
+ if( !move_pos( replens[rep_index], true ) ) return 0;
+ return replens[rep_index];
+ }
+
+ if( main_len >= matchfinder.match_len_limit() )
+ {
+ trials[0].dis = match_distances[matchfinder.match_len_limit()] +
+ num_rep_distances;
+ trials[0].price = main_len;
+ if( !move_pos( main_len, true ) ) return 0;
+ return main_len;
+ }
+
+ trials[0].state = state;
+ for( int i = 0; i < num_rep_distances; ++i ) trials[0].reps[i] = reps[i];
+
+ const uint8_t cur_byte = matchfinder[0];
+ const uint8_t match_byte = matchfinder[-reps[0]-1];
+ unsigned int position = matchfinder.data_position();
+ const int pos_state = position & pos_state_mask;
+
+ trials[1].dis = -1;
+ trials[1].prev_index = 0;
+ trials[1].price = price0( bm_match[state()][pos_state] );
+ if( state.is_char() )
+ trials[1].price += literal_encoder.price_symbol( matchfinder[-1], cur_byte );
+ else
+ trials[1].price += literal_encoder.price_matched( matchfinder[-1], cur_byte, match_byte );
+
+ const int match_price = price1( bm_match[state()][pos_state] );
+ const int rep_match_price = match_price + price1( bm_rep[state()] );
+
+ if( match_byte == cur_byte )
+ trials[1].update( 0, 0, rep_match_price + price_rep_len1( state, pos_state ) );
+
+ if( main_len < min_match_len )
+ {
+ trials[0].dis = trials[1].dis;
+ trials[0].price = 1;
+ if( !matchfinder.move_pos() ) return 0;
+ return 1;
+ }
+
+ {
+ const int normal_match_price = match_price + price0( bm_rep[state()] );
+ int len = min_match_len;
+ if( main_len <= replens[rep_index] )
+ {
+ main_len = replens[rep_index];
+ for( ; len <= main_len; ++len ) trials[len].price = infinite_price;
+ }
+ else for( ; len <= main_len; ++len )
+ {
+ trials[len].dis = match_distances[len] + num_rep_distances;
+ trials[len].prev_index = 0;
+ trials[len].price = normal_match_price +
+ price_pair( match_distances[len], len, pos_state );
+ }
+ }
+
+ for( int rep = 0; rep < num_rep_distances; ++rep )
+ for( int len = min_match_len; len <= replens[rep]; ++len )
+ trials[len].update( rep, 0, rep_match_price +
+ price_rep( rep, len, state, pos_state ) );
+
+ int cur = 0;
+ int num_trials = main_len;
+ if( !matchfinder.move_pos() ) return 0;
+
+ while( true )
+ {
+ if( ++cur >= num_trials )
+ {
+ backward( cur );
+ return cur;
+ }
+ const int newlen = read_match_distances();
+ if( newlen >= matchfinder.match_len_limit() )
+ {
+ longest_match_found = newlen;
+ backward( cur );
+ return cur;
+ }
+
+ Trial & cur_trial = trials[cur];
+ const int prev_index = cur_trial.prev_index;
+
+ cur_trial.state = trials[prev_index].state;
+
+ for( int i = 0; i < num_rep_distances; ++i )
+ cur_trial.reps[i] = trials[prev_index].reps[i];
+ if( prev_index == cur - 1 )
+ {
+ if( cur_trial.dis == 0 ) cur_trial.state.set_short_rep();
+ else cur_trial.state.set_char();
+ }
+ else
+ {
+ if( cur_trial.dis < num_rep_distances ) cur_trial.state.set_rep();
+ else cur_trial.state.set_match();
+ mtf_reps( cur_trial.dis, cur_trial.reps );
+ }
+
+ const uint8_t cur_byte = matchfinder[0];
+ const uint8_t match_byte = matchfinder[-cur_trial.reps[0]-1];
+ const int pos_state = ++position & pos_state_mask;
+ int next_price = cur_trial.price + price0( bm_match[cur_trial.state()][pos_state] );
+ if( cur_trial.state.is_char() )
+ next_price += literal_encoder.price_symbol( matchfinder[-1], cur_byte );
+ else
+ next_price += literal_encoder.price_matched( matchfinder[-1], cur_byte, match_byte );
+ if( !matchfinder.move_pos() ) return 0;
+
+ Trial & next_trial = trials[cur+1];
+
+ next_trial.update( -1, cur, next_price );
+
+ const int match_price = cur_trial.price + price1( bm_match[cur_trial.state()][pos_state] );
+ const int rep_match_price = match_price + price1( bm_rep[cur_trial.state()] );
+
+ if( match_byte == cur_byte && next_trial.dis != 0 )
+ next_trial.update( 0, cur, rep_match_price +
+ price_rep_len1( cur_trial.state, pos_state ) );
+
+ const int len_limit = std::min( std::min( max_num_trials - 1 - cur,
+ matchfinder.available_bytes() ), matchfinder.match_len_limit() );
+ if( len_limit < min_match_len ) continue;
+
+ for( int rep = 0; rep < num_rep_distances; ++rep )
+ {
+ const int dis = cur_trial.reps[rep] + 1;
+ int len = 0;
+ const uint8_t * const data = matchfinder.ptr_to_current_pos() - 1;
+ while( len < len_limit && data[len] == data[len-dis] ) ++len;
+ if( len >= min_match_len )
+ {
+ while( num_trials < cur + len )
+ trials[++num_trials].price = infinite_price;
+ for( ; len >= min_match_len; --len )
+ trials[cur+len].update( rep, cur, rep_match_price +
+ price_rep( rep, len, cur_trial.state, pos_state ) );
+ }
+ }
+
+ if( newlen <= len_limit &&
+ ( newlen > min_match_len ||
+ ( newlen == min_match_len &&
+ match_distances[newlen] < modeled_distances ) ) )
+ {
+ const int normal_match_price = match_price +
+ price0( bm_rep[cur_trial.state()] );
+ while( num_trials < cur + newlen )
+ trials[++num_trials].price = infinite_price;
+
+ for( int len = newlen; len >= min_match_len; --len )
+ trials[cur+len].update( match_distances[len] + num_rep_distances, cur,
+ normal_match_price +
+ price_pair( match_distances[len], len, pos_state ) );
+ }
+ }
+ }
+
+
+ // End Of Stream mark => (dis == 0xFFFFFFFF, len == min_match_len)
+void LZ_encoder::flush( const State & state )
+ {
+ const int pos_state = ( matchfinder.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( 0xFFFFFFFF, min_match_len, pos_state );
+ range_encoder.flush();
+ File_trailer trailer;
+ trailer.data_crc( crc() );
+ trailer.data_size( matchfinder.data_position() );
+ trailer.member_size( range_encoder.member_position() + sizeof trailer );
+ for( unsigned int i = 0; i < sizeof trailer; ++i )
+ range_encoder.put_byte( (( uint8_t *)&trailer)[i] );
+ range_encoder.flush_data();
+ }
+
+
+LZ_encoder::LZ_encoder( Matchfinder & mf, const File_header & header,
+ const int odes )
+ :
+ longest_match_found( 0 ),
+ crc_( 0xFFFFFFFF ),
+ matchfinder( mf ),
+ range_encoder( odes ),
+ len_encoder( matchfinder.match_len_limit() ),
+ rep_match_len_encoder( matchfinder.match_len_limit() ),
+ literal_encoder(),
+ num_dis_slots( 2 * File_header::real_bits( matchfinder.dictionary_size() - 1 ) )
+ {
+ fill_align_prices();
+
+ for( unsigned int i = 0; i < sizeof header; ++i )
+ range_encoder.put_byte( (( uint8_t *)&header)[i] );
+ }
+
+
+bool LZ_encoder::encode_member( const long long member_size )
+ {
+ if( range_encoder.member_position() != sizeof( File_header ) )
+ return false; // can be called only once
+ const long long member_size_limit = member_size - sizeof( File_trailer ) - 15;
+ int fill_counter = 0;
+ int rep_distances[num_rep_distances];
+ State state;
+ uint8_t prev_byte = 0;
+ for( int i = 0; i < num_rep_distances; ++i ) rep_distances[i] = 0;
+
+ if( !matchfinder.finished() ) // copy first byte
+ {
+ range_encoder.encode_bit( bm_match[state()][0], 0 );
+ const uint8_t cur_byte = matchfinder[0];
+ literal_encoder.encode( range_encoder, prev_byte, cur_byte );
+ prev_byte = cur_byte;
+ crc32.update( crc_, cur_byte );
+ if( !move_pos( 1 ) ) return false;
+ }
+
+ while( true )
+ {
+ if( matchfinder.finished() ) { flush( state ); return true; }
+ if( fill_counter <= 0 ) { fill_distance_prices(); fill_counter = 512; }
+
+ int ahead = best_pair_sequence( rep_distances, state );
+ if( ahead <= 0 ) return false;
+ fill_counter -= ahead;
+
+ for( int i = 0; ; )
+ {
+ const int pos_state = ( matchfinder.data_position() - ahead ) & pos_state_mask;
+ int dis = trials[i].dis;
+ const int len = trials[i].price;
+
+ bool bit = ( dis < 0 && len == 1 );
+ range_encoder.encode_bit( bm_match[state()][pos_state], !bit );
+ if( bit )
+ {
+ const uint8_t cur_byte = matchfinder[-ahead];
+ if( state.is_char() )
+ literal_encoder.encode( range_encoder, prev_byte, cur_byte );
+ else
+ {
+ const uint8_t match_byte = matchfinder[-rep_distances[0]-1-ahead];
+ literal_encoder.encode_matched( range_encoder, prev_byte, match_byte, cur_byte );
+ }
+ state.set_char();
+ prev_byte = cur_byte;
+ }
+ else
+ {
+ 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();
+ }
+ prev_byte = matchfinder[len-1-ahead];
+ }
+ for( int j = 0; j < len; ++j )
+ crc32.update( crc_, matchfinder[j-ahead] );
+ ahead -= len; i += len;
+ if( range_encoder.member_position() >= member_size_limit )
+ {
+ if( !matchfinder.dec_pos( ahead ) ) return false;
+ flush( state );
+ return true;
+ }
+ if( ahead <= 0 ) break;
+ }
+ }
+ }