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-rw-r--r--encoder.cc89
1 files changed, 47 insertions, 42 deletions
diff --git a/encoder.cc b/encoder.cc
index 27d3db0..b197e22 100644
--- a/encoder.cc
+++ b/encoder.cc
@@ -36,7 +36,7 @@ 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 );
+ const int rd = readblock( infd_, buffer + stream_pos, size );
stream_pos += rd;
if( rd < size ) at_stream_end = true;
return ( rd == size || !errno );
@@ -44,13 +44,13 @@ bool Matchfinder::read_block() throw()
Matchfinder::Matchfinder( const int dict_size, const int len_limit,
- const int ides )
+ const int infd )
:
partial_data_pos( 0 ),
pos( 0 ),
cyclic_pos( 0 ),
stream_pos( 0 ),
- ides_( ides ),
+ infd_( infd ),
match_len_limit_( len_limit ),
prev_positions( new int32_t[num_prev_positions] ),
at_stream_end( false )
@@ -80,7 +80,7 @@ Matchfinder::Matchfinder( const int dict_size, const int len_limit,
bool Matchfinder::reset() throw()
{
const int size = stream_pos - pos;
- std::memmove( buffer, buffer + pos, size );
+ if( size > 0 ) std::memmove( buffer, buffer + pos, size );
partial_data_pos = 0;
stream_pos -= pos;
pos = 0;
@@ -130,10 +130,11 @@ int Matchfinder::longest_match_len( int * const distances ) throw()
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 );
+ const uint32_t tmp = crc32[data[0]] ^ data[1] ^ ( (uint32_t)data[2] << 8 );
+ const int key3 = num_prev_positions4 +
+ (int)( tmp & ( num_prev_positions3 - 1 ) );
+ const int key4 = (int)( ( tmp ^ ( crc32[data[3]] << 5 ) ) &
+ ( num_prev_positions4 - 1 ) );
if( distances )
{
@@ -242,8 +243,8 @@ 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 * const dsp = dis_slot_prices[dis_state];
+ const Bit_model * const 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 );
@@ -251,7 +252,7 @@ void LZ_encoder::fill_distance_prices() throw()
dsp[slot] = price_symbol( bmds, slot, dis_slot_bits ) +
(((( slot >> 1 ) - 1 ) - dis_align_bits ) << price_shift );
- int * dp = dis_prices[dis_state];
+ int * const dp = dis_prices[dis_state];
int dis = 0;
for( ; dis < start_dis_model; ++dis )
dp[dis] = dsp[dis];
@@ -267,8 +268,10 @@ void LZ_encoder::fill_distance_prices() throw()
}
-// Return value: ( dis == -1 ) && ( len == 1 ) means literal
-int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances],
+// Return value == number of bytes advanced (ahead).
+// trials[0]..trials[retval-1] contain the steps to encode.
+// ( trials[0].dis == -1 && trials[0].price == 1 ) means literal.
+int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances],
const State & state )
{
int main_len;
@@ -303,15 +306,14 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances],
return main_len;
}
- trials[0].state = state;
- for( int i = 0; i < num_rep_distances; ++i ) trials[0].reps[i] = reps[i];
-
+ {
+ const int pos_state = matchfinder.data_position() & pos_state_mask;
const uint8_t prev_byte = matchfinder[-1];
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[0].state = state;
+ for( int i = 0; i < num_rep_distances; ++i ) trials[0].reps[i] = reps[i];
trials[1].dis = -1;
trials[1].prev_index = 0;
trials[1].price = price0( bm_match[state()][pos_state] );
@@ -359,6 +361,7 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances],
trials[len].update( rep, 0, price +
rep_match_len_encoder.price( len, pos_state ) );
}
+ }
int cur = 0;
int num_trials = main_len;
@@ -366,7 +369,7 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances],
while( true )
{
- if( ++cur >= num_trials )
+ if( ++cur >= num_trials ) // no more initialized trials
{
backward( cur );
return cur;
@@ -398,10 +401,11 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances],
mtf_reps( cur_trial.dis, cur_trial.reps );
}
+ const int pos_state = matchfinder.data_position() & pos_state_mask;
const uint8_t prev_byte = matchfinder[-1];
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( prev_byte, cur_byte );
@@ -445,7 +449,7 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances],
if( newlen <= len_limit &&
( newlen > min_match_len ||
( newlen == min_match_len &&
- match_distances[newlen] < modeled_distances ) ) )
+ match_distances[min_match_len] < modeled_distances ) ) )
{
const int normal_match_price = match_price +
price0( bm_rep[cur_trial.state()] );
@@ -461,54 +465,55 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances],
}
- // End Of Stream mark => (dis == 0xFFFFFFFF, len == min_match_len)
+ // End Of Stream mark => (dis == 0xFFFFFFFFU, len == min_match_len)
void LZ_encoder::full_flush( const State & state )
{
- const int pos_state = ( matchfinder.data_position() ) & pos_state_mask;
+ 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 );
+ encode_pair( 0xFFFFFFFFU, 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] );
+ 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();
}
LZ_encoder::LZ_encoder( Matchfinder & mf, const File_header & header,
- const int odes )
+ const int outfd )
:
longest_match_found( 0 ),
- crc_( 0xFFFFFFFF ),
+ crc_( 0xFFFFFFFFU ),
matchfinder( mf ),
- range_encoder( odes ),
+ range_encoder( outfd ),
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] );
+ for( int i = 0; i < File_header::size; ++i )
+ range_encoder.put_byte( header.data[i] );
}
bool LZ_encoder::encode_member( const long long member_size )
{
- if( range_encoder.member_position() != sizeof( File_header ) )
+ if( range_encoder.member_position() != File_header::size )
return false; // can be called only once
- const long long member_size_limit = member_size - sizeof( File_trailer ) - 16;
+ const long long member_size_limit =
+ member_size - File_trailer::size() - max_marker_size;
int fill_counter = 0;
int rep_distances[num_rep_distances];
State state;
for( int i = 0; i < num_rep_distances; ++i ) rep_distances[i] = 0;
- if( !matchfinder.finished() ) // encode first byte
+ // encode first byte
+ if( matchfinder.data_position() == 0 && !matchfinder.finished() )
{
range_encoder.encode_bit( bm_match[state()][0], 0 );
const uint8_t prev_byte = 0;
@@ -523,22 +528,23 @@ bool LZ_encoder::encode_member( const long long member_size )
if( matchfinder.finished() ) { full_flush( state ); return true; }
if( fill_counter <= 0 ) { fill_distance_prices(); fill_counter = 512; }
- int ahead = best_pair_sequence( rep_distances, state );
+ int ahead = sequence_optimizer( 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 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 )
+ if( bit ) // literal byte
{
const uint8_t prev_byte = matchfinder[-ahead-1];
const uint8_t cur_byte = matchfinder[-ahead];
+ crc32.update( crc_, cur_byte );
if( state.is_char() )
literal_encoder.encode( range_encoder, prev_byte, cur_byte );
else
@@ -548,8 +554,9 @@ bool LZ_encoder::encode_member( const long long member_size )
}
state.set_char();
}
- else
+ else // match or repeated match
{
+ crc32.update( crc_, matchfinder.ptr_to_current_pos() - ahead, len );
mtf_reps( dis, rep_distances );
bit = ( dis < num_rep_distances );
range_encoder.encode_bit( bm_rep[state()], bit );
@@ -578,8 +585,6 @@ bool LZ_encoder::encode_member( const long long member_size )
state.set_match();
}
}
- 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 )
{