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-rw-r--r--encoder.h589
1 files changed, 62 insertions, 527 deletions
diff --git a/encoder.h b/encoder.h
index 6f50da7..81cc1e0 100644
--- a/encoder.h
+++ b/encoder.h
@@ -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 );
};