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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/>.
+*/
+
+enum { price_shift_bits = 6,
+ price_step_bits = 2,
+ price_step = 1 << price_step_bits };
+
+class Dis_slots
+ {
+ uint8_t data[1<<10];
+
+public:
+ void init()
+ {
+ for( int slot = 0; slot < 4; ++slot ) data[slot] = slot;
+ for( int i = 4, size = 2, slot = 4; slot < 20; slot += 2 )
+ {
+ std::memset( &data[i], slot, size );
+ std::memset( &data[i+size], slot + 1, size );
+ size <<= 1;
+ i += size;
+ }
+ }
+
+ uint8_t operator[]( const int dis ) const { return data[dis]; }
+ };
+
+extern Dis_slots dis_slots;
+
+inline uint8_t get_slot( const unsigned dis )
+ {
+ if( dis < (1 << 10) ) return dis_slots[dis];
+ if( dis < (1 << 19) ) return dis_slots[dis>> 9] + 18;
+ if( dis < (1 << 28) ) return dis_slots[dis>>18] + 36;
+ return dis_slots[dis>>27] + 54;
+ }
+
+
+class Prob_prices
+ {
+ short data[bit_model_total >> price_step_bits];
+
+public:
+ void init()
+ {
+ for( int i = 0; i < bit_model_total >> price_step_bits; ++i )
+ {
+ unsigned val = ( i * price_step ) + ( price_step / 2 );
+ int bits = 0; // base 2 logarithm of val
+ for( int j = 0; j < price_shift_bits; ++j )
+ {
+ val = val * val;
+ bits <<= 1;
+ while( val >= 1 << 16 ) { val >>= 1; ++bits; }
+ }
+ bits += 15; // remaining bits in val
+ data[i] = ( bit_model_total_bits << price_shift_bits ) - bits;
+ }
+ }
+
+ int operator[]( const int probability ) const
+ { return data[probability >> price_step_bits]; }
+ };
+
+extern Prob_prices prob_prices;
+
+
+inline int price0( const Bit_model bm )
+ { return prob_prices[bm.probability]; }
+
+inline int price1( const Bit_model bm )
+ { return prob_prices[bit_model_total - bm.probability]; }
+
+inline int price_bit( const Bit_model bm, const bool bit )
+ { return ( bit ? price1( bm ) : price0( bm ) ); }
+
+
+inline int price_symbol3( const Bit_model bm[], int symbol )
+ {
+ bool bit = symbol & 1;
+ symbol |= 8; symbol >>= 1;
+ int price = price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ return price + price_bit( bm[1], symbol & 1 );
+ }
+
+
+inline int price_symbol6( const Bit_model bm[], unsigned symbol )
+ {
+ bool bit = symbol & 1;
+ symbol |= 64; symbol >>= 1;
+ int price = price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ return price + price_bit( bm[1], symbol & 1 );
+ }
+
+
+inline int price_symbol8( const Bit_model bm[], int symbol )
+ {
+ bool bit = symbol & 1;
+ symbol |= 0x100; symbol >>= 1;
+ int price = price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ bit = symbol & 1; symbol >>= 1; price += price_bit( bm[symbol], bit );
+ return price + price_bit( bm[1], symbol & 1 );
+ }
+
+
+inline int price_symbol_reversed( const Bit_model bm[], int symbol,
+ const int num_bits )
+ {
+ int price = 0;
+ int model = 1;
+ for( int i = num_bits; i > 0; --i )
+ {
+ const bool bit = symbol & 1;
+ symbol >>= 1;
+ price += price_bit( bm[model], bit );
+ model <<= 1; model |= bit;
+ }
+ return price;
+ }
+
+
+inline int price_matched( const Bit_model bm[], unsigned symbol,
+ unsigned match_byte )
+ {
+ int price = 0;
+ unsigned mask = 0x100;
+ symbol |= mask;
+ while( true )
+ {
+ const unsigned match_bit = ( match_byte <<= 1 ) & mask;
+ const bool bit = ( symbol <<= 1 ) & 0x100;
+ price += price_bit( bm[(symbol>>9)+match_bit+mask], bit );
+ if( symbol >= 0x10000 ) return price;
+ mask &= ~(match_bit ^ symbol); // if( match_bit != bit ) mask = 0;
+ }
+ }
+
+
+class Matchfinder_base
+ {
+ bool read_block();
+ void normalize_pos();
+
+ Matchfinder_base( const Matchfinder_base & ); // declared as private
+ void operator=( const Matchfinder_base & ); // declared as private
+
+protected:
+ unsigned long long partial_data_pos;
+ uint8_t * buffer; // input buffer
+ int32_t * prev_positions; // 1 + last seen position of key. else 0
+ int32_t * pos_array; // may be tree or chain
+ const int before_size; // bytes to keep in buffer before dictionary
+ int buffer_size;
+ int dictionary_size; // bytes to keep in buffer before pos
+ int pos; // current pos in buffer
+ int cyclic_pos; // cycles through [0, dictionary_size]
+ int stream_pos; // first byte not yet read from file
+ int pos_limit; // when reached, a new block must be read
+ int key4_mask;
+ const int num_prev_positions23;
+ int num_prev_positions; // size of prev_positions
+ int pos_array_size;
+ const int infd; // input file descriptor
+ bool at_stream_end; // stream_pos shows real end of file
+
+ Matchfinder_base( const int before_size_,
+ const int dict_size, const int after_size,
+ const int dict_factor, const int num_prev_positions23_,
+ const int pos_array_factor, const int ifd );
+
+ ~Matchfinder_base()
+ { delete[] prev_positions; std::free( buffer ); }
+
+public:
+ uint8_t peek( const int distance ) const { return buffer[pos-distance]; }
+ int available_bytes() const { return stream_pos - pos; }
+ unsigned long long data_position() const { return partial_data_pos + pos; }
+ bool data_finished() const { return at_stream_end && pos >= stream_pos; }
+ const uint8_t * ptr_to_current_pos() const { return buffer + pos; }
+
+ int true_match_len( const int index, const int distance ) const
+ {
+ const uint8_t * const data = buffer + pos;
+ int i = index;
+ const int len_limit = std::min( available_bytes(), (int)max_match_len );
+ while( i < len_limit && data[i-distance] == data[i] ) ++i;
+ return i;
+ }
+
+ void move_pos()
+ {
+ if( ++cyclic_pos > dictionary_size ) cyclic_pos = 0;
+ if( ++pos >= pos_limit ) normalize_pos();
+ }
+
+ void reset();
+ };
+
+
+class Range_encoder
+ {
+ enum { buffer_size = 65536 };
+ uint64_t low;
+ unsigned long long partial_member_pos;
+ uint8_t * const buffer; // output buffer
+ int pos; // current pos in buffer
+ uint32_t range;
+ unsigned ff_count;
+ const int outfd; // output file descriptor
+ uint8_t cache;
+ Lzip_header header;
+
+ void shift_low()
+ {
+ if( low >> 24 != 0xFF )
+ {
+ const bool carry = ( low > 0xFFFFFFFFU );
+ put_byte( cache + carry );
+ for( ; ff_count > 0; --ff_count ) put_byte( 0xFF + carry );
+ cache = low >> 24;
+ }
+ else ++ff_count;
+ low = ( low & 0x00FFFFFFU ) << 8;
+ }
+
+ Range_encoder( const Range_encoder & ); // declared as private
+ void operator=( const Range_encoder & ); // declared as private
+
+public:
+ void reset( const unsigned dictionary_size )
+ {
+ low = 0;
+ partial_member_pos = 0;
+ pos = 0;
+ range = 0xFFFFFFFFU;
+ ff_count = 0;
+ cache = 0;
+ header.dictionary_size( dictionary_size );
+ for( int i = 0; i < Lzip_header::size; ++i )
+ put_byte( header.data[i] );
+ }
+
+ Range_encoder( const unsigned dictionary_size, const int ofd )
+ :
+ buffer( new uint8_t[buffer_size] ), outfd( ofd )
+ {
+ header.set_magic();
+ reset( dictionary_size );
+ }
+
+ ~Range_encoder() { delete[] buffer; }
+
+ unsigned long long member_position() const
+ { return partial_member_pos + pos + ff_count; }
+
+ void flush() { for( int i = 0; i < 5; ++i ) shift_low(); }
+ void flush_data();
+
+ void put_byte( const uint8_t b )
+ {
+ buffer[pos] = b;
+ if( ++pos >= buffer_size ) flush_data();
+ }
+
+ void encode( const int symbol, const int num_bits )
+ {
+ for( unsigned mask = 1 << ( num_bits - 1 ); mask > 0; mask >>= 1 )
+ {
+ range >>= 1;
+ if( symbol & mask ) low += range;
+ if( range <= 0x00FFFFFFU ) { range <<= 8; shift_low(); }
+ }
+ }
+
+ void encode_bit( Bit_model & bm, const bool bit )
+ {
+ const uint32_t bound = ( range >> bit_model_total_bits ) * bm.probability;
+ if( !bit )
+ {
+ range = bound;
+ bm.probability +=
+ ( bit_model_total - bm.probability ) >> bit_model_move_bits;
+ }
+ else
+ {
+ low += bound;
+ range -= bound;
+ bm.probability -= bm.probability >> bit_model_move_bits;
+ }
+ if( range <= 0x00FFFFFFU ) { range <<= 8; shift_low(); }
+ }
+
+ void encode_tree3( Bit_model bm[], const int symbol )
+ {
+ bool bit = ( symbol >> 2 ) & 1;
+ encode_bit( bm[1], bit );
+ int model = 2 | bit;
+ bit = ( symbol >> 1 ) & 1;
+ encode_bit( bm[model], bit ); model <<= 1; model |= bit;
+ encode_bit( bm[model], symbol & 1 );
+ }
+
+ void encode_tree6( Bit_model bm[], const unsigned symbol )
+ {
+ bool bit = ( symbol >> 5 ) & 1;
+ encode_bit( bm[1], bit );
+ int model = 2 | bit;
+ bit = ( symbol >> 4 ) & 1;
+ encode_bit( bm[model], bit ); model <<= 1; model |= bit;
+ bit = ( symbol >> 3 ) & 1;
+ encode_bit( bm[model], bit ); model <<= 1; model |= bit;
+ bit = ( symbol >> 2 ) & 1;
+ encode_bit( bm[model], bit ); model <<= 1; model |= bit;
+ bit = ( symbol >> 1 ) & 1;
+ encode_bit( bm[model], bit ); model <<= 1; model |= bit;
+ encode_bit( bm[model], symbol & 1 );
+ }
+
+ void encode_tree8( Bit_model bm[], const int symbol )
+ {
+ int model = 1;
+ for( int i = 7; i >= 0; --i )
+ {
+ const bool bit = ( symbol >> i ) & 1;
+ encode_bit( bm[model], bit );
+ model <<= 1; model |= bit;
+ }
+ }
+
+ void encode_tree_reversed( Bit_model bm[], int symbol, const int num_bits )
+ {
+ int model = 1;
+ for( int i = num_bits; i > 0; --i )
+ {
+ const bool bit = symbol & 1;
+ symbol >>= 1;
+ encode_bit( bm[model], bit );
+ model <<= 1; model |= bit;
+ }
+ }
+
+ void encode_matched( Bit_model bm[], unsigned symbol, unsigned match_byte )
+ {
+ unsigned mask = 0x100;
+ symbol |= mask;
+ while( true )
+ {
+ const unsigned match_bit = ( match_byte <<= 1 ) & mask;
+ const bool bit = ( symbol <<= 1 ) & 0x100;
+ encode_bit( bm[(symbol>>9)+match_bit+mask], bit );
+ if( symbol >= 0x10000 ) break;
+ mask &= ~(match_bit ^ symbol); // if( match_bit != bit ) mask = 0;
+ }
+ }
+
+ void encode_len( Len_model & lm, int symbol, const int pos_state )
+ {
+ bool bit = ( ( symbol -= min_match_len ) >= len_low_symbols );
+ encode_bit( lm.choice1, bit );
+ if( !bit )
+ encode_tree3( lm.bm_low[pos_state], symbol );
+ else
+ {
+ bit = ( ( symbol -= len_low_symbols ) >= len_mid_symbols );
+ encode_bit( lm.choice2, bit );
+ if( !bit )
+ encode_tree3( lm.bm_mid[pos_state], symbol );
+ else
+ encode_tree8( lm.bm_high, symbol - len_mid_symbols );
+ }
+ }
+ };
+
+
+class LZ_encoder_base : public Matchfinder_base
+ {
+protected:
+ enum { max_marker_size = 16,
+ num_rep_distances = 4 }; // must be 4
+
+ uint32_t crc_;
+
+ Bit_model bm_literal[1<<literal_context_bits][0x300];
+ Bit_model bm_match[State::states][pos_states];
+ Bit_model bm_rep[State::states];
+ Bit_model bm_rep0[State::states];
+ Bit_model bm_rep1[State::states];
+ Bit_model bm_rep2[State::states];
+ Bit_model bm_len[State::states][pos_states];
+ Bit_model bm_dis_slot[len_states][1<<dis_slot_bits];
+ Bit_model bm_dis[modeled_distances-end_dis_model+1];
+ Bit_model bm_align[dis_align_size];
+ Len_model match_len_model;
+ Len_model rep_len_model;
+ Range_encoder renc;
+
+ LZ_encoder_base( const int before_size, const int dict_size,
+ const int after_size, const int dict_factor,
+ const int num_prev_positions23,
+ const int pos_array_factor,
+ const int ifd, const int outfd )
+ :
+ Matchfinder_base( before_size, dict_size, after_size, dict_factor,
+ num_prev_positions23, pos_array_factor, ifd ),
+ crc_( 0xFFFFFFFFU ),
+ renc( dictionary_size, outfd )
+ {}
+
+ unsigned crc() const { return crc_ ^ 0xFFFFFFFFU; }
+
+ int price_literal( const uint8_t prev_byte, const uint8_t symbol ) const
+ { return price_symbol8( bm_literal[get_lit_state(prev_byte)], symbol ); }
+
+ int price_matched( const uint8_t prev_byte, const uint8_t symbol,
+ const uint8_t match_byte ) const
+ { return ::price_matched( bm_literal[get_lit_state(prev_byte)], symbol,
+ match_byte ); }
+
+ void encode_literal( const uint8_t prev_byte, const uint8_t symbol )
+ { renc.encode_tree8( bm_literal[get_lit_state(prev_byte)], symbol ); }
+
+ void encode_matched( const uint8_t prev_byte, const uint8_t symbol,
+ const uint8_t match_byte )
+ { renc.encode_matched( bm_literal[get_lit_state(prev_byte)], symbol,
+ match_byte ); }
+
+ void encode_pair( const unsigned dis, const int len, const int pos_state )
+ {
+ renc.encode_len( match_len_model, len, pos_state );
+ const unsigned dis_slot = get_slot( dis );
+ renc.encode_tree6( bm_dis_slot[get_len_state(len)], dis_slot );
+
+ if( dis_slot >= start_dis_model )
+ {
+ const int direct_bits = ( dis_slot >> 1 ) - 1;
+ const unsigned base = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
+ const unsigned direct_dis = dis - base;
+
+ if( dis_slot < end_dis_model )
+ renc.encode_tree_reversed( bm_dis + ( base - dis_slot ),
+ direct_dis, direct_bits );
+ else
+ {
+ renc.encode( direct_dis >> dis_align_bits, direct_bits - dis_align_bits );
+ renc.encode_tree_reversed( bm_align, direct_dis, dis_align_bits );
+ }
+ }
+ }
+
+ void full_flush( const State state );
+
+public:
+ virtual ~LZ_encoder_base() {}
+
+ unsigned long long member_position() const { return renc.member_position(); }
+ virtual void reset();
+
+ virtual bool encode_member( const unsigned long long member_size ) = 0;
+ };