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authorDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 11:45:45 +0000
committerDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 11:45:45 +0000
commit5e8398a39d8758cb4dee9a43f92ac958277e0ebd (patch)
tree10ba2517467532e4a002f47cc32732f1f335eae0 /mtester.h
parentAdding upstream version 1.16~pre1. (diff)
downloadlziprecover-5e8398a39d8758cb4dee9a43f92ac958277e0ebd.tar.xz
lziprecover-5e8398a39d8758cb4dee9a43f92ac958277e0ebd.zip
Adding upstream version 1.16~pre2.upstream/1.16_pre2
Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>
Diffstat (limited to '')
-rw-r--r--mtester.h300
1 files changed, 300 insertions, 0 deletions
diff --git a/mtester.h b/mtester.h
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+/* Lziprecover - Data recovery tool for lzip files
+ Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014 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
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+class Range_mtester
+ {
+ const uint8_t * const buffer; // input buffer
+ const long buffer_size;
+ long pos; // current pos in buffer
+ uint32_t code;
+ uint32_t range;
+ bool at_stream_end;
+
+ void operator=( const Range_mtester & ); // declared as private
+
+public:
+ Range_mtester( const uint8_t * const buf, const long buf_size )
+ :
+ buffer( buf ),
+ buffer_size( buf_size ),
+ pos( File_header::size ),
+ code( 0 ),
+ range( 0xFFFFFFFFU ),
+ at_stream_end( false )
+ {}
+
+ void load()
+ {
+ for( int i = 0; i < 5; ++i ) code = (code << 8) | get_byte();
+ code &= range; // make sure that first byte is discarded
+ }
+
+ bool code_is_zero() const { return ( code == 0 ); }
+ bool finished() { return pos >= buffer_size; }
+ long member_position() const { return pos; }
+
+ const File_trailer * get_trailer()
+ {
+ if( buffer_size - pos < File_trailer::size ) return 0;
+ const File_trailer * const p = (File_trailer *)(buffer + pos);
+ pos += File_trailer::size;
+ return p;
+ }
+
+ uint8_t get_byte()
+ {
+ if( finished() ) return 0xAA; // make code != 0
+ return buffer[pos++];
+ }
+
+ void normalize()
+ {
+ if( range <= 0x00FFFFFFU )
+ { range <<= 8; code = (code << 8) | get_byte(); }
+ }
+
+ int decode( const int num_bits )
+ {
+ int symbol = 0;
+ for( int i = num_bits; i > 0; --i )
+ {
+ normalize();
+ range >>= 1;
+// symbol <<= 1;
+// if( code >= range ) { code -= range; symbol |= 1; }
+ const uint32_t mask = 0U - (code < range);
+ code -= range;
+ code += range & mask;
+ symbol = (symbol << 1) + (mask + 1);
+ }
+ return symbol;
+ }
+
+ int decode_bit( Bit_model & bm )
+ {
+ normalize();
+ 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;
+ return 0;
+ }
+ else
+ {
+ range -= bound;
+ code -= bound;
+ bm.probability -= bm.probability >> bit_model_move_bits;
+ return 1;
+ }
+ }
+
+ int decode_tree3( Bit_model bm[] )
+ {
+ int symbol = 1;
+ symbol = ( symbol << 1 ) | decode_bit( bm[symbol] );
+ symbol = ( symbol << 1 ) | decode_bit( bm[symbol] );
+ symbol = ( symbol << 1 ) | decode_bit( bm[symbol] );
+ return symbol & 7;
+ }
+
+ int decode_tree6( Bit_model bm[] )
+ {
+ int symbol = 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] );
+ symbol = ( symbol << 1 ) | decode_bit( bm[symbol] );
+ return symbol & 0x3F;
+ }
+
+ int decode_tree8( Bit_model bm[] )
+ {
+ int symbol = 1;
+ while( symbol < 0x100 )
+ symbol = ( symbol << 1 ) | decode_bit( bm[symbol] );
+ return symbol & 0xFF;
+ }
+
+ int decode_tree_reversed( Bit_model bm[], const int num_bits )
+ {
+ int model = 1;
+ int symbol = 0;
+ for( int i = 0; i < num_bits; ++i )
+ {
+ const bool bit = decode_bit( bm[model] );
+ model <<= 1;
+ if( bit ) { ++model; symbol |= (1 << i); }
+ }
+ return symbol;
+ }
+
+ int decode_tree_reversed4( Bit_model bm[] )
+ {
+ int model = 1;
+ int symbol = decode_bit( bm[model] );
+ model = (model << 1) + symbol;
+ int bit = decode_bit( bm[model] );
+ model = (model << 1) + bit; symbol |= (bit << 1);
+ bit = decode_bit( bm[model] );
+ model = (model << 1) + bit; symbol |= (bit << 2);
+ if( decode_bit( bm[model] ) ) symbol |= 8;
+ return symbol;
+ }
+
+ int decode_matched( Bit_model bm[], int match_byte )
+ {
+ Bit_model * const bm1 = bm + 0x100;
+ int symbol = 1;
+ while( symbol < 0x100 )
+ {
+ match_byte <<= 1;
+ const int match_bit = match_byte & 0x100;
+ const int bit = decode_bit( bm1[match_bit+symbol] );
+ symbol = ( symbol << 1 ) | bit;
+ if( match_bit != bit << 8 )
+ {
+ while( symbol < 0x100 )
+ symbol = ( symbol << 1 ) | decode_bit( bm[symbol] );
+ break;
+ }
+ }
+ return symbol & 0xFF;
+ }
+
+ int decode_len( Len_model & lm, const int pos_state )
+ {
+ if( decode_bit( lm.choice1 ) == 0 )
+ return decode_tree3( lm.bm_low[pos_state] );
+ 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 );
+ }
+ };
+
+
+class LZ_mtester
+ {
+ unsigned long long partial_data_pos;
+ Range_mtester rdec;
+ const unsigned dictionary_size;
+ const int buffer_size;
+ uint8_t * buffer; // output buffer
+ int pos; // current pos in buffer
+ int stream_pos; // first byte not yet written to file
+ uint32_t crc_;
+ unsigned rep0; // rep[0-3] latest four distances
+ unsigned rep1; // used for efficient coding of
+ unsigned rep2; // repeated distances
+ unsigned rep3;
+ State state;
+
+ 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];
+
+ Len_model match_len_model;
+ Len_model rep_len_model;
+
+ unsigned long long stream_position() const
+ { return partial_data_pos + stream_pos; }
+ void flush_data();
+ bool verify_trailer();
+
+ uint8_t get_prev_byte() const
+ {
+ const int i = ( ( pos > 0 ) ? pos : buffer_size ) - 1;
+ return buffer[i];
+ }
+
+ uint8_t get_byte( const int distance ) const
+ {
+ int i = pos - distance - 1;
+ if( i < 0 ) i += buffer_size;
+ return buffer[i];
+ }
+
+ void put_byte( const uint8_t b )
+ {
+ buffer[pos] = b;
+ if( ++pos >= buffer_size ) flush_data();
+ }
+
+ void copy_block( const int distance, int len )
+ {
+ int i = pos - distance - 1;
+ if( i < 0 ) i += buffer_size;
+ if( len < buffer_size - std::max( pos, i ) && len <= std::abs( pos - i ) )
+ {
+ std::memcpy( buffer + pos, buffer + i, len ); // no wrap, no overlap
+ pos += len;
+ }
+ else for( ; len > 0; --len )
+ {
+ buffer[pos] = buffer[i];
+ if( ++pos >= buffer_size ) flush_data();
+ if( ++i >= buffer_size ) i = 0;
+ }
+ }
+
+ void operator=( const LZ_mtester & ); // declared as private
+
+public:
+ LZ_mtester( const uint8_t * const ibuf, const long ibuf_size,
+ const int dict_size )
+ :
+ partial_data_pos( 0 ),
+ rdec( ibuf, ibuf_size ),
+ dictionary_size( dict_size ),
+ buffer_size( std::max( 65536U, dictionary_size ) ),
+ buffer( new uint8_t[buffer_size] ),
+ pos( 0 ),
+ stream_pos( 0 ),
+ crc_( 0xFFFFFFFFU ),
+ rep0( 0 ),
+ rep1( 0 ),
+ rep2( 0 ),
+ rep3( 0 )
+ { buffer[buffer_size-1] = 0; } // prev_byte of first byte
+
+ ~LZ_mtester() { delete[] buffer; }
+
+ unsigned crc() const { return crc_ ^ 0xFFFFFFFFU; }
+ unsigned long long data_position() const { return partial_data_pos + pos; }
+ bool finished() { return rdec.finished(); }
+ long member_position() const { return rdec.member_position(); }
+
+ void duplicate_buffer();
+ int test_member( const long pos_limit = LONG_MAX );
+ };
+
+
+uint8_t * read_member( const int infd, const long long mpos,
+ const long long msize );
+const LZ_mtester * prepare_master( const uint8_t * const buffer,
+ const long buffer_size,
+ const long pos_limit );
+bool test_member_rest( const LZ_mtester & master, long * const failure_posp = 0 );