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Diffstat (limited to 'lzip.h')
| -rw-r--r-- | lzip.h | 358 |
1 files changed, 358 insertions, 0 deletions
@@ -0,0 +1,358 @@ +/* Lzip - LZMA lossless data compressor + Copyright (C) 2008-2022 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 + the Free Software Foundation, either version 2 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 State + { + int st; + +public: + enum { states = 12 }; + State() : st( 0 ) {} + int operator()() const { return st; } + bool is_char() const { return st < 7; } + + void set_char() + { + static const int next[states] = { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 }; + st = next[st]; + } + bool is_char_set_char() { set_char(); return st < 4; } + void set_char_rep() { st = 8; } + void set_match() { st = ( st < 7 ) ? 7 : 10; } + void set_rep() { st = ( st < 7 ) ? 8 : 11; } + void set_short_rep() { st = ( st < 7 ) ? 9 : 11; } + }; + + +enum { + min_dictionary_bits = 12, + min_dictionary_size = 1 << min_dictionary_bits, // >= modeled_distances + max_dictionary_bits = 29, + max_dictionary_size = 1 << max_dictionary_bits, + min_member_size = 36, + literal_context_bits = 3, + literal_pos_state_bits = 0, // not used + pos_state_bits = 2, + pos_states = 1 << pos_state_bits, + pos_state_mask = pos_states - 1, + + len_states = 4, + dis_slot_bits = 6, + start_dis_model = 4, + end_dis_model = 14, + modeled_distances = 1 << (end_dis_model / 2), // 128 + dis_align_bits = 4, + dis_align_size = 1 << dis_align_bits, + + len_low_bits = 3, + len_mid_bits = 3, + len_high_bits = 8, + len_low_symbols = 1 << len_low_bits, + len_mid_symbols = 1 << len_mid_bits, + len_high_symbols = 1 << len_high_bits, + max_len_symbols = len_low_symbols + len_mid_symbols + len_high_symbols, + + min_match_len = 2, // must be 2 + max_match_len = min_match_len + max_len_symbols - 1, // 273 + min_match_len_limit = 5 }; + +inline int get_len_state( const int len ) + { return std::min( len - min_match_len, len_states - 1 ); } + +inline int get_lit_state( const uint8_t prev_byte ) + { return prev_byte >> ( 8 - literal_context_bits ); } + + +enum { bit_model_move_bits = 5, + bit_model_total_bits = 11, + bit_model_total = 1 << bit_model_total_bits }; + +struct Bit_model + { + int probability; + void reset() { probability = bit_model_total / 2; } + void reset( const int size ) + { for( int i = 0; i < size; ++i ) this[i].reset(); } + Bit_model() { reset(); } + }; + +struct Len_model + { + Bit_model choice1; + Bit_model choice2; + Bit_model bm_low[pos_states][len_low_symbols]; + Bit_model bm_mid[pos_states][len_mid_symbols]; + Bit_model bm_high[len_high_symbols]; + + void reset() + { + choice1.reset(); + choice2.reset(); + bm_low[0][0].reset( pos_states * len_low_symbols ); + bm_mid[0][0].reset( pos_states * len_mid_symbols ); + bm_high[0].reset( len_high_symbols ); + } + }; + + +// defined in main.cc +extern int verbosity; + +class Pretty_print // requires global var 'int verbosity' + { + std::string name_; + std::string padded_name; + const char * const stdin_name; + unsigned longest_name; + mutable bool first_post; + +public: + Pretty_print( const std::vector< std::string > & filenames ) + : stdin_name( "(stdin)" ), longest_name( 0 ), first_post( false ) + { + if( verbosity <= 0 ) return; + const unsigned stdin_name_len = std::strlen( stdin_name ); + for( unsigned i = 0; i < filenames.size(); ++i ) + { + const std::string & s = filenames[i]; + const unsigned len = ( s == "-" ) ? stdin_name_len : s.size(); + if( longest_name < len ) longest_name = len; + } + if( longest_name == 0 ) longest_name = stdin_name_len; + } + + void set_name( const std::string & filename ) + { + if( filename.size() && filename != "-" ) name_ = filename; + else name_ = stdin_name; + padded_name = " "; padded_name += name_; padded_name += ": "; + if( longest_name > name_.size() ) + padded_name.append( longest_name - name_.size(), ' ' ); + first_post = true; + } + + void reset() const { if( name_.size() ) first_post = true; } + const char * name() const { return name_.c_str(); } + void operator()( const char * const msg = 0 ) const; + }; + + +class CRC32 + { + uint32_t data[256]; // Table of CRCs of all 8-bit messages. + +public: + CRC32() + { + for( unsigned n = 0; n < 256; ++n ) + { + unsigned c = n; + for( int k = 0; k < 8; ++k ) + { if( c & 1 ) c = 0xEDB88320U ^ ( c >> 1 ); else c >>= 1; } + data[n] = c; + } + } + + uint32_t operator[]( const uint8_t byte ) const { return data[byte]; } + + void update_byte( uint32_t & crc, const uint8_t byte ) const + { crc = data[(crc^byte)&0xFF] ^ ( crc >> 8 ); } + + // about as fast as it is possible without messing with endianness + void update_buf( uint32_t & crc, const uint8_t * const buffer, + const int size ) const + { + uint32_t c = crc; + for( int i = 0; i < size; ++i ) + c = data[(c^buffer[i])&0xFF] ^ ( c >> 8 ); + crc = c; + } + }; + +extern const CRC32 crc32; + + +inline bool isvalid_ds( const unsigned dictionary_size ) + { return ( dictionary_size >= min_dictionary_size && + dictionary_size <= max_dictionary_size ); } + + +inline int real_bits( unsigned value ) + { + int bits = 0; + while( value > 0 ) { value >>= 1; ++bits; } + return bits; + } + + +const uint8_t lzip_magic[4] = { 0x4C, 0x5A, 0x49, 0x50 }; // "LZIP" + +struct Lzip_header + { + uint8_t data[6]; // 0-3 magic bytes + // 4 version + // 5 coded dictionary size + enum { size = 6 }; + + void set_magic() { std::memcpy( data, lzip_magic, 4 ); data[4] = 1; } + bool verify_magic() const + { return ( std::memcmp( data, lzip_magic, 4 ) == 0 ); } + + bool verify_prefix( const int sz ) const // detect (truncated) header + { + for( int i = 0; i < sz && i < 4; ++i ) + if( data[i] != lzip_magic[i] ) return false; + return ( sz > 0 ); + } + + bool verify_corrupt() const // detect corrupt header + { + int matches = 0; + for( int i = 0; i < 4; ++i ) + if( data[i] == lzip_magic[i] ) ++matches; + return ( matches > 1 && matches < 4 ); + } + + uint8_t version() const { return data[4]; } + bool verify_version() const { return ( data[4] == 1 ); } + + unsigned dictionary_size() const + { + unsigned sz = ( 1 << ( data[5] & 0x1F ) ); + if( sz > min_dictionary_size ) + sz -= ( sz / 16 ) * ( ( data[5] >> 5 ) & 7 ); + return sz; + } + + bool dictionary_size( const unsigned sz ) + { + if( !isvalid_ds( sz ) ) return false; + data[5] = real_bits( sz - 1 ); + if( sz > min_dictionary_size ) + { + const unsigned base_size = 1 << data[5]; + const unsigned fraction = base_size / 16; + for( unsigned i = 7; i >= 1; --i ) + if( base_size - ( i * fraction ) >= sz ) + { data[5] |= ( i << 5 ); break; } + } + return true; + } + + bool verify() const + { return verify_magic() && verify_version() && + isvalid_ds( dictionary_size() ); } + }; + + +struct Lzip_trailer + { + uint8_t data[20]; // 0-3 CRC32 of the uncompressed data + // 4-11 size of the uncompressed data + // 12-19 member size including header and trailer + enum { size = 20 }; + + unsigned data_crc() const + { + unsigned tmp = 0; + for( int i = 3; i >= 0; --i ) { tmp <<= 8; tmp += data[i]; } + return tmp; + } + + void data_crc( unsigned crc ) + { for( int i = 0; i <= 3; ++i ) { data[i] = (uint8_t)crc; crc >>= 8; } } + + unsigned long long data_size() const + { + unsigned long long tmp = 0; + for( int i = 11; i >= 4; --i ) { tmp <<= 8; tmp += data[i]; } + return tmp; + } + + void data_size( unsigned long long sz ) + { for( int i = 4; i <= 11; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } } + + unsigned long long member_size() const + { + unsigned long long tmp = 0; + for( int i = 19; i >= 12; --i ) { tmp <<= 8; tmp += data[i]; } + return tmp; + } + + void member_size( unsigned long long sz ) + { for( int i = 12; i <= 19; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } } + + bool verify_consistency() const // check internal consistency + { + const unsigned crc = data_crc(); + const unsigned long long dsize = data_size(); + if( ( crc == 0 ) != ( dsize == 0 ) ) return false; + const unsigned long long msize = member_size(); + if( msize < min_member_size ) return false; + const unsigned long long mlimit = ( 9 * dsize + 7 ) / 8 + min_member_size; + if( mlimit > dsize && msize > mlimit ) return false; + const unsigned long long dlimit = 7090 * ( msize - 26 ) - 1; + if( dlimit > msize && dsize > dlimit ) return false; + return true; + } + }; + + +struct Error + { + const char * const msg; + explicit Error( const char * const s ) : msg( s ) {} + }; + +inline void set_retval( int & retval, const int new_val ) + { if( retval < new_val ) retval = new_val; } + +const char * const bad_magic_msg = "Bad magic number (file not in lzip format)."; +const char * const bad_dict_msg = "Invalid dictionary size in member header."; +const char * const corrupt_mm_msg = "Corrupt header in multimember file."; +const char * const trailing_msg = "Trailing data not allowed."; + +// defined in decoder.cc +int readblock( const int fd, uint8_t * const buf, const int size ); +int writeblock( const int fd, const uint8_t * const buf, const int size ); + +// defined in list.cc +int list_files( const std::vector< std::string > & filenames, + const bool ignore_trailing, const bool loose_trailing ); + +// defined in main.cc +struct stat; +const char * bad_version( const unsigned version ); +const char * format_ds( const unsigned dictionary_size ); +void show_header( const unsigned dictionary_size ); +int open_instream( const char * const name, struct stat * const in_statsp, + const bool one_to_one, const bool reg_only = false ); +void show_error( const char * const msg, const int errcode = 0, + const bool help = false ); +void show_file_error( const char * const filename, const char * const msg, + const int errcode = 0 ); +void internal_error( const char * const msg ); +class Matchfinder_base; +void show_cprogress( const unsigned long long cfile_size = 0, + const unsigned long long partial_size = 0, + const Matchfinder_base * const m = 0, + const Pretty_print * const p = 0 ); +class Range_decoder; +void show_dprogress( const unsigned long long cfile_size = 0, + const unsigned long long partial_size = 0, + const Range_decoder * const d = 0, + const Pretty_print * const p = 0 ); |