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-rw-r--r--encoder.h77
1 files changed, 43 insertions, 34 deletions
diff --git a/encoder.h b/encoder.h
index 5f65743..eecdae4 100644
--- a/encoder.h
+++ b/encoder.h
@@ -1,5 +1,5 @@
/* Lzlib - A compression library for lzip files
- Copyright (C) 2009, 2010 Antonio Diaz Diaz.
+ Copyright (C) 2009, 2010, 2011 Antonio Diaz Diaz.
This library is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -25,8 +25,10 @@
Public License.
*/
-const int max_num_trials = 1 << 12;
-const int price_shift = 6;
+namespace Lzlib {
+
+enum { max_num_trials = 1 << 12,
+ price_shift = 6 };
class Dis_slots
{
@@ -45,6 +47,8 @@ public:
}
}
+ unsigned char table( const int dis ) const throw() { return data[dis]; }
+
int operator[]( const uint32_t dis ) const throw()
{
if( dis < (1 << 12) ) return data[dis];
@@ -53,8 +57,7 @@ public:
}
};
-namespace Lzlib_namespace { extern const Dis_slots dis_slots; }
-using Lzlib_namespace::dis_slots;
+extern const Dis_slots dis_slots;
class Prob_prices
@@ -65,13 +68,13 @@ public:
Prob_prices()
{
const int num_bits = ( bit_model_total_bits - 2 );
- for( int i = num_bits - 1; i >= 0; --i )
+ int j = 1, end = 2;
+ data[0] = bit_model_total_bits << price_shift;
+ for( int i = num_bits - 1; i >= 0; --i, end <<= 1 )
{
- int start = 1 << ( num_bits - i - 1 );
- int end = 1 << ( num_bits - i);
- for( int j = start; j < end; ++j )
- data[j] = (i << price_shift) +
- ( ((end - j) << price_shift) >> (num_bits - i - 1) );
+ for( ; j < end; ++j )
+ data[j] = ( i << price_shift ) +
+ ( ( (end - j) << price_shift ) >> ( num_bits - i - 1 ) );
}
}
@@ -79,8 +82,7 @@ public:
{ return data[probability >> 2]; }
};
-namespace Lzlib_namespace { extern const Prob_prices prob_prices; }
-using Lzlib_namespace::prob_prices;
+extern const Prob_prices prob_prices;
inline int price0( const Bit_model & bm ) throw()
@@ -95,8 +97,8 @@ inline int price_bit( const Bit_model & bm, const int bit ) throw()
inline int price_symbol( const Bit_model bm[], int symbol, const int num_bits ) throw()
{
- symbol |= ( 1 << num_bits );
int price = 0;
+ symbol |= ( 1 << num_bits );
while( symbol > 1 )
{
const int bit = symbol & 1;
@@ -165,14 +167,15 @@ class Matchfinder
long long partial_data_pos;
const int dictionary_size_; // bytes to keep in buffer before pos
const int buffer_size;
- uint8_t * const buffer;
- int pos;
- int cyclic_pos;
+ uint8_t * const buffer; // input buffer
+ int32_t * const prev_positions; // last seen position of key
+ int32_t * const prev_pos_tree;
+ int pos; // current pos in buffer
+ int cyclic_pos; // current pos in dictionary
int stream_pos; // first byte not yet read from file
const int pos_limit; // when reached, a new block must be read
const int match_len_limit_;
- int32_t * const prev_positions; // last seen position of key
- int32_t * prev_pos_tree;
+ const int cycles;
bool at_stream_end_; // stream_pos shows real end of file
bool been_flushed;
@@ -187,8 +190,8 @@ public:
int available_bytes() const throw() { return stream_pos - pos; }
long long data_position() const throw() { return partial_data_pos + pos; }
int dictionary_size() const throw() { return dictionary_size_; }
- void flushing( const bool b ) throw() { at_stream_end_ = b; }
bool finished() const throw() { return at_stream_end_ && pos >= stream_pos; }
+ void flushing( const bool b ) throw() { at_stream_end_ = b; }
int free_bytes() const throw()
{ if( at_stream_end_ ) return 0; return buffer_size - stream_pos; }
int match_len_limit() const throw() { return match_len_limit_; }
@@ -258,6 +261,9 @@ public:
ff_count( 0 ),
cache( 0 ) {}
+ long long member_position() const throw()
+ { return partial_member_pos + used_bytes() + ff_count; }
+
bool enough_free_bytes() const throw()
{ return free_bytes() >= min_free_bytes; }
@@ -277,9 +283,6 @@ public:
cache = 0;
}
- long long member_position() const throw()
- { return partial_member_pos + used_bytes() + ff_count; }
-
void encode( const int symbol, const int num_bits )
{
for( int i = num_bits - 1; i >= 0; --i )
@@ -408,24 +411,28 @@ class Literal_encoder
{ return ( prev_byte >> ( 8 - literal_context_bits ) ); }
public:
- void encode( Range_encoder & range_encoder, uint8_t prev_byte, uint8_t symbol )
+ void encode( Range_encoder & range_encoder,
+ uint8_t prev_byte, uint8_t symbol )
{ range_encoder.encode_tree( bm_literal[lstate(prev_byte)], symbol, 8 ); }
- void encode_matched( Range_encoder & range_encoder, uint8_t prev_byte, uint8_t match_byte, uint8_t symbol )
- { range_encoder.encode_matched( bm_literal[lstate(prev_byte)], symbol, match_byte ); }
-
- int price_matched( uint8_t prev_byte, uint8_t symbol, uint8_t match_byte ) const throw()
- { return ::price_matched( bm_literal[lstate(prev_byte)], symbol, match_byte ); }
+ void encode_matched( Range_encoder & range_encoder,
+ uint8_t prev_byte, uint8_t symbol, uint8_t match_byte )
+ { range_encoder.encode_matched( bm_literal[lstate(prev_byte)],
+ symbol, match_byte ); }
int price_symbol( uint8_t prev_byte, uint8_t symbol ) const throw()
- { return ::price_symbol( bm_literal[lstate(prev_byte)], symbol, 8 ); }
+ { return Lzlib::price_symbol( bm_literal[lstate(prev_byte)], symbol, 8 ); }
+
+ int price_matched( uint8_t prev_byte, uint8_t symbol,
+ uint8_t match_byte ) const throw()
+ { return Lzlib::price_matched( bm_literal[lstate(prev_byte)],
+ symbol, match_byte ); }
};
class LZ_encoder
{
- enum { dis_align_mask = dis_align_size - 1,
- infinite_price = 0x0FFFFFFF,
+ enum { infinite_price = 0x0FFFFFFF,
max_marker_size = 16,
num_rep_distances = 4 }; // must be 4
@@ -451,7 +458,7 @@ class LZ_encoder
Bit_model bm_rep2[State::states];
Bit_model bm_len[State::states][pos_states];
Bit_model bm_dis_slot[max_dis_states][1<<dis_slot_bits];
- Bit_model bm_dis[modeled_distances-end_dis_model];
+ Bit_model bm_dis[modeled_distances-end_dis_model+1];
Bit_model bm_align[dis_align_size];
Matchfinder & matchfinder;
@@ -525,7 +532,7 @@ class LZ_encoder
price += dis_prices[dis_state][dis];
else
price += dis_slot_prices[dis_state][dis_slots[dis]] +
- align_prices[dis & dis_align_mask];
+ align_prices[dis & (dis_align_size - 1)];
return price;
}
@@ -604,3 +611,5 @@ public:
long long member_position() const throw()
{ return range_encoder.member_position(); }
};
+
+} // end namespace Lzlib