diff options
Diffstat (limited to 'mtester.h')
| -rw-r--r-- | mtester.h | 123 |
1 files changed, 88 insertions, 35 deletions
@@ -1,5 +1,5 @@ /* Lziprecover - Data recovery tool for the lzip format - Copyright (C) 2009-2021 Antonio Diaz Diaz. + Copyright (C) 2009-2022 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 @@ -17,7 +17,7 @@ class Range_mtester { - const uint8_t * const buffer; // input buffer + const uint8_t * const buffer; // input buffer const long long buffer_size; long long pos; // current pos in buffer uint32_t code; @@ -96,37 +96,78 @@ public: } else { - range -= bound; code -= bound; + range -= bound; bm.probability -= bm.probability >> bit_model_move_bits; return 1; } } - unsigned decode_tree3( Bit_model bm[] ) + void decode_symbol_bit( Bit_model & bm, unsigned & symbol ) + { + normalize(); + symbol <<= 1; + const uint32_t bound = ( range >> bit_model_total_bits ) * bm.probability; + if( code < bound ) + { + range = bound; + bm.probability += + ( bit_model_total - bm.probability ) >> bit_model_move_bits; + } + else + { + code -= bound; + range -= bound; + bm.probability -= bm.probability >> bit_model_move_bits; + symbol |= 1; + } + } + + void decode_symbol_bit_reversed( Bit_model & bm, unsigned & model, + unsigned & symbol, const int i ) { - unsigned symbol = 2 | decode_bit( bm[1] ); - symbol = ( symbol << 1 ) | decode_bit( bm[symbol] ); - symbol = ( symbol << 1 ) | decode_bit( bm[symbol] ); - return symbol & 7; + normalize(); + model <<= 1; + const uint32_t bound = ( range >> bit_model_total_bits ) * bm.probability; + if( code < bound ) + { + range = bound; + bm.probability += + ( bit_model_total - bm.probability ) >> bit_model_move_bits; + } + else + { + code -= bound; + range -= bound; + bm.probability -= bm.probability >> bit_model_move_bits; + model |= 1; + symbol |= 1 << i; + } } unsigned decode_tree6( Bit_model bm[] ) { - unsigned symbol = 2 | decode_bit( bm[1] ); - symbol = ( symbol << 1 ) | decode_bit( bm[symbol] ); - symbol = ( symbol << 1 ) | decode_bit( bm[symbol] ); - symbol = ( symbol << 1 ) | decode_bit( bm[symbol] ); - symbol = ( symbol << 1 ) | decode_bit( bm[symbol] ); - symbol = ( symbol << 1 ) | decode_bit( bm[symbol] ); + unsigned symbol = 1; + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); return symbol & 0x3F; } unsigned decode_tree8( Bit_model bm[] ) { unsigned symbol = 1; - for( int i = 0; i < 8; ++i ) - symbol = ( symbol << 1 ) | decode_bit( bm[symbol] ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); return symbol & 0xFF; } @@ -135,20 +176,18 @@ public: unsigned model = 1; unsigned symbol = 0; for( int i = 0; i < num_bits; ++i ) - { - const unsigned bit = decode_bit( bm[model] ); - model <<= 1; model += bit; - symbol |= ( bit << i ); - } + decode_symbol_bit_reversed( bm[model], model, symbol, i ); return symbol; } unsigned decode_tree_reversed4( Bit_model bm[] ) { - unsigned symbol = decode_bit( bm[1] ); - symbol += decode_bit( bm[2+symbol] ) << 1; - symbol += decode_bit( bm[4+symbol] ) << 2; - symbol += decode_bit( bm[8+symbol] ) << 3; + unsigned model = 1; + unsigned symbol = 0; + decode_symbol_bit_reversed( bm[model], model, symbol, 0 ); + decode_symbol_bit_reversed( bm[model], model, symbol, 1 ); + decode_symbol_bit_reversed( bm[model], model, symbol, 2 ); + decode_symbol_bit_reversed( bm[model], model, symbol, 3 ); return symbol; } @@ -163,8 +202,7 @@ public: symbol <<= 1; symbol |= bit; if( match_bit >> 8 != bit ) { - while( symbol < 0x100 ) - symbol = ( symbol << 1 ) | decode_bit( bm[symbol] ); + while( symbol < 0x100 ) decode_symbol_bit( bm[symbol], symbol ); break; } } @@ -173,11 +211,24 @@ public: unsigned decode_len( Len_model & lm, const int pos_state ) { + Bit_model * bm; + unsigned mask, offset, symbol = 1; + if( decode_bit( lm.choice1 ) == 0 ) - return decode_tree3( lm.bm_low[pos_state] ); + { bm = lm.bm_low[pos_state]; mask = 7; offset = 0; goto len3; } if( decode_bit( lm.choice2 ) == 0 ) - return len_low_symbols + decode_tree3( lm.bm_mid[pos_state] ); - return len_low_symbols + len_mid_symbols + decode_tree8( lm.bm_high ); + { bm = lm.bm_mid[pos_state]; mask = 7; offset = len_low_symbols; goto len3; } + bm = lm.bm_high; mask = 0xFF; offset = len_low_symbols + len_mid_symbols; + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); +len3: + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + decode_symbol_bit( bm[symbol], symbol ); + return ( symbol & mask ) + min_match_len + offset; } }; @@ -206,6 +257,7 @@ class LZ_mtester unsigned max_packet_size_; // maximum packet size found unsigned max_marker_size_; // maximum marker size found bool pos_wrapped; + bool buffer_is_external; Bit_model bm_literal[1<<literal_context_bits][0x300]; Bit_model bm_match[State::states][pos_states]; @@ -306,11 +358,11 @@ public: max_rep0( 0 ), max_packet_size_( 0 ), max_marker_size_( 0 ), - pos_wrapped( false ) + pos_wrapped( false ), buffer_is_external( false ) // prev_byte of first byte; also for peek( 0 ) on corrupt file { buffer[dictionary_size-1] = 0; } - ~LZ_mtester() { delete[] buffer; } + ~LZ_mtester() { if( !buffer_is_external ) delete[] buffer; } unsigned crc() const { return crc_ ^ 0xFFFFFFFFU; } unsigned long long data_position() const { return partial_data_pos + pos; } @@ -324,13 +376,14 @@ public: unsigned max_packet_size() const { return max_packet_size_; } unsigned max_marker_size() const { return max_marker_size_; } - const uint8_t * get_buffers( const uint8_t ** prev_bufferp, - int * sizep, int * prev_sizep ) const + const uint8_t * get_buffers( const uint8_t ** const prev_bufferp, + int * const sizep, int * const prev_sizep ) const { *sizep = ( pos_wrapped && pos == 0 ) ? dictionary_size : pos; *prev_sizep = ( pos_wrapped && pos > 0 ) ? dictionary_size - pos : 0; *prev_bufferp = buffer + pos; return buffer; } - void duplicate_buffer(); + void duplicate_buffer( uint8_t * const buffer2 ); + // these two functions set max_rep0 int test_member( const unsigned long long mpos_limit = LLONG_MAX, const unsigned long long dpos_limit = LLONG_MAX, |