diff options
Diffstat (limited to '')
| -rw-r--r-- | encoder.h | 589 |
1 files changed, 62 insertions, 527 deletions
@@ -1,5 +1,5 @@ /* Lzip - LZMA lossless data compressor - Copyright (C) 2008-2014 Antonio Diaz Diaz. + Copyright (C) 2008-2015 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 @@ -15,429 +15,6 @@ along with this program. If not, see <http://www.gnu.org/licenses/>. */ -enum { max_num_trials = 1 << 13, - 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 int bit ) - { if( bit ) return price1( bm ); else return price0( bm ); } - - -inline int price_symbol3( const Bit_model bm[], int symbol ) - { - int 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[], int symbol ) - { - int 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 ) - { - int 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 int bit = symbol & 1; - price += price_bit( bm[model], bit ); - model = ( model << 1 ) | bit; - symbol >>= 1; - } - return price; - } - - -inline int price_matched( const Bit_model bm[], int symbol, int match_byte ) - { - int price = 0; - int mask = 0x100; - symbol |= mask; - - do { - match_byte <<= 1; - const int match_bit = match_byte & mask; - symbol <<= 1; - const int bit = symbol & 0x100; - price += price_bit( bm[match_bit+(symbol>>9)+mask], bit ); - mask &= ~(match_byte ^ symbol); // if( match_bit != bit ) mask = 0; - } - while( symbol < 0x10000 ); - return price; - } - - -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; - 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, 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 operator[]( 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; } - int dictionary_size() const { return dictionary_size_; } - bool 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, int len_limit ) const - { - if( index + len_limit > available_bytes() ) - len_limit = available_bytes() - index; - const uint8_t * const data = buffer + pos + index; - int i = 0; - 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(); - }; - - -struct Pair /* distance-length pair */ - { - int dis; - int len; - }; - - -class Matchfinder : public Matchfinder_base - { - enum { before_size = max_num_trials + 1, - // bytes to keep in buffer after pos - after_size = ( 2 * max_match_len ) + 1, - dict_factor = 2, - num_prev_positions3 = 1 << 16, - num_prev_positions2 = 1 << 10, - num_prev_positions23 = num_prev_positions2 + num_prev_positions3, - pos_array_factor = 2 }; - - const int cycles; - const int match_len_limit_; - -public: - Matchfinder( const int dict_size, const int len_limit, const int ifd ) - : - Matchfinder_base( before_size, dict_size, after_size, dict_factor, - num_prev_positions23, pos_array_factor, ifd ), - cycles( ( len_limit < max_match_len ) ? 16 + ( len_limit / 2 ) : 256 ), - match_len_limit_( len_limit ) - {} - - bool dec_pos( const int ahead ) - { - if( ahead < 0 || pos < ahead ) return false; - pos -= ahead; - cyclic_pos -= ahead; - if( cyclic_pos < 0 ) cyclic_pos += dictionary_size_ + 1; - return true; - } - - int match_len_limit() const { return match_len_limit_; } - int get_match_pairs( Pair * pairs = 0 ); - }; - - -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; - - void shift_low() - { - const bool carry = ( low > 0xFFFFFFFFU ); - if( carry || low < 0xFF000000U ) - { - 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: - explicit Range_encoder( const int ofd ) - : - low( 0 ), - partial_member_pos( 0 ), - buffer( new uint8_t[buffer_size] ), - pos( 0 ), - range( 0xFFFFFFFFU ), - ff_count( 0 ), - outfd( ofd ), - cache( 0 ) - {} - - ~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( int i = num_bits - 1; i >= 0; --i ) - { - range >>= 1; - if( (symbol >> i) & 1 ) low += range; - if( range <= 0x00FFFFFFU ) { range <<= 8; shift_low(); } - } - } - - void encode_bit( Bit_model & bm, const int 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 ) - { - int model = 1; - int bit = ( symbol >> 2 ) & 1; - encode_bit( bm[model], bit ); model = ( model << 1 ) | bit; - bit = ( symbol >> 1 ) & 1; - encode_bit( bm[model], bit ); model = ( model << 1 ) | bit; - encode_bit( bm[model], symbol & 1 ); - } - - void encode_tree6( Bit_model bm[], const int symbol ) - { - int model = 1; - int bit = ( symbol >> 5 ) & 1; - encode_bit( bm[model], bit ); model = ( model << 1 ) | bit; - bit = ( symbol >> 4 ) & 1; - encode_bit( bm[model], bit ); model = ( model << 1 ) | bit; - bit = ( symbol >> 3 ) & 1; - encode_bit( bm[model], bit ); model = ( model << 1 ) | bit; - bit = ( symbol >> 2 ) & 1; - encode_bit( bm[model], bit ); model = ( model << 1 ) | bit; - bit = ( symbol >> 1 ) & 1; - encode_bit( bm[model], bit ); model = ( model << 1 ) | bit; - encode_bit( bm[model], symbol & 1 ); - } - - void encode_tree8( Bit_model bm[], const int symbol ) - { - int model = 1; - int mask = ( 1 << 7 ); - do { - const int bit = ( symbol & mask ); - encode_bit( bm[model], bit ); - model <<= 1; if( bit ) ++model; - } - while( mask >>= 1 ); - } - - 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 int bit = symbol & 1; - encode_bit( bm[model], bit ); - model = ( model << 1 ) | bit; - symbol >>= 1; - } - } - - void encode_matched( Bit_model bm[], int symbol, int match_byte ) - { - int mask = 0x100; - symbol |= mask; - - do { - match_byte <<= 1; - const int match_bit = match_byte & mask; - symbol <<= 1; - const int bit = symbol & 0x100; - encode_bit( bm[match_bit+(symbol>>9)+mask], bit ); - mask &= ~(match_byte ^ symbol); // if( match_bit != bit ) mask = 0; - } - while( symbol < 0x10000 ); - } - - void encode_len( Len_model & lm, int symbol, const int pos_state ) - { - symbol -= min_match_len; - bool bit = ( symbol >= 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 - len_low_symbols ); - else - encode_tree8( lm.bm_high, symbol - len_low_symbols - len_mid_symbols ); - } - } - }; - - class Len_prices { const Len_model & lm; @@ -471,14 +48,14 @@ class Len_prices } public: + void reset() { for( int i = 0; i < pos_states; ++i ) counters[i] = 0; } + Len_prices( const Len_model & m, const int match_len_limit ) : lm( m ), len_symbols( match_len_limit + 1 - min_match_len ), count( ( match_len_limit > 12 ) ? 1 : len_symbols ) - { - for( int i = 0; i < pos_states; ++i ) counters[i] = 0; - } + { reset(); } void decrement_counter( const int pos_state ) { --counters[pos_state]; } @@ -497,101 +74,28 @@ public: }; -class LZ_encoder_base +class LZ_encoder : public LZ_encoder_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]; - Bit_model bm_align[dis_align_size]; - - Range_encoder renc; - Len_model match_len_model; - Len_model rep_len_model; - - unsigned crc() const { return crc_ ^ 0xFFFFFFFFU; } - - LZ_encoder_base( const File_header & header, const int outfd ) - : - crc_( 0xFFFFFFFFU ), - renc( outfd ) - { - for( int i = 0; i < File_header::size; ++i ) - renc.put_byte( header.data[i] ); - } - - 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 ) + struct Pair /* distance-length pair */ { - renc.encode_len( match_len_model, len, pos_state ); - const int 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 - 1, 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 unsigned long long data_position, const State state ); - -public: - unsigned long long member_position() const { return renc.member_position(); } - }; - + int dis; + int len; + }; -class LZ_encoder : public LZ_encoder_base - { enum { infinite_price = 0x0FFFFFFF, + max_num_trials = 1 << 13, single_step_trial = -2, dual_step_trial = -1 }; struct Trial { State state; - int price; // dual use var; cumulative price, match length - int dis; // rep index or match distance. (-1 for literal) - int prev_index; // index of prev trial in trials[] - int prev_index2; // -2 trial is single step - // -1 literal + rep0 - // >= 0 ( rep or match ) + literal + rep0 + int price; /* dual use var; cumulative price, match length */ + int dis; /* rep index or match distance. (-1 for literal) */ + int prev_index; /* index of prev trial in trials[] */ + int prev_index2; /* -2 trial is single step */ + /* -1 literal + rep0 */ + /* >= 0 ( rep or match ) + literal + rep0 */ int reps[num_rep_distances]; void update( const int pr, const int distance, const int p_i ) @@ -616,7 +120,8 @@ class LZ_encoder : public LZ_encoder_base } }; - Matchfinder & matchfinder; + const int cycles; + const int match_len_limit; Len_prices match_len_prices; Len_prices rep_len_prices; int pending_num_pairs; @@ -628,9 +133,19 @@ class LZ_encoder : public LZ_encoder_base int align_prices[dis_align_size]; const int num_dis_slots; + bool dec_pos( const int ahead ) + { + if( ahead < 0 || pos < ahead ) return false; + pos -= ahead; + cyclic_pos -= ahead; + if( cyclic_pos < 0 ) cyclic_pos += dictionary_size + 1; + return true; + } + + int get_match_pairs( Pair * pairs = 0 ); void update_distance_prices(); - // move-to-front dis in/into reps if( dis > 0 ) + /* move-to-front dis in/into reps if( dis > 0 ) */ static void mtf_reps( const int dis, int reps[num_rep_distances] ) { if( dis >= num_rep_distances ) @@ -685,27 +200,27 @@ class LZ_encoder : public LZ_encoder_base int read_match_distances() { - const int num_pairs = matchfinder.get_match_pairs( pairs ); + const int num_pairs = get_match_pairs( pairs ); if( num_pairs > 0 ) { int len = pairs[num_pairs-1].len; - if( len == matchfinder.match_len_limit() && len < max_match_len ) + if( len == match_len_limit && len < max_match_len ) { - len += matchfinder.true_match_len( len, pairs[num_pairs-1].dis + 1, - max_match_len - len ); + len += true_match_len( len, pairs[num_pairs-1].dis + 1, + max_match_len - len ); pairs[num_pairs-1].len = len; } } return num_pairs; } - void move_pos( int n ) + void move_and_update( int n ) { while( true ) { - matchfinder.move_pos(); + move_pos(); if( --n <= 0 ) break; - matchfinder.get_match_pairs(); + get_match_pairs(); } } @@ -739,16 +254,36 @@ class LZ_encoder : public LZ_encoder_base int sequence_optimizer( const int reps[num_rep_distances], const State state ); + enum { before = max_num_trials + 1, + /* bytes to keep in buffer after pos */ + after_size = ( 2 * max_match_len ) + 1, + dict_factor = 2, + num_prev_positions3 = 1 << 16, + num_prev_positions2 = 1 << 10, + num_prev_positions23 = num_prev_positions2 + num_prev_positions3, + pos_array_factor = 2 }; + public: - LZ_encoder( Matchfinder & mf, const File_header & header, const int outfd ) + LZ_encoder( const int dict_size, const int len_limit, + const int ifd, const int outfd ) : - LZ_encoder_base( header, outfd ), - matchfinder( mf ), - match_len_prices( match_len_model, mf.match_len_limit() ), - rep_len_prices( rep_len_model, mf.match_len_limit() ), + LZ_encoder_base( before, dict_size, after_size, dict_factor, + num_prev_positions23, pos_array_factor, ifd, outfd ), + cycles( ( len_limit < max_match_len ) ? 16 + ( len_limit / 2 ) : 256 ), + match_len_limit( len_limit ), + match_len_prices( match_len_model, match_len_limit ), + rep_len_prices( rep_len_model, match_len_limit ), pending_num_pairs( 0 ), - num_dis_slots( 2 * real_bits( mf.dictionary_size() - 1 ) ) + num_dis_slots( 2 * real_bits( dictionary_size - 1 ) ) {} + void reset() + { + LZ_encoder_base::reset(); + match_len_prices.reset(); + rep_len_prices.reset(); + pending_num_pairs = 0; + } + bool encode_member( const unsigned long long member_size ); }; |