diff options
Diffstat (limited to 'encoder.h')
| -rw-r--r-- | encoder.h | 77 |
1 files changed, 43 insertions, 34 deletions
@@ -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 |