diff options
Diffstat (limited to 'lzip.h')
| -rw-r--r-- | lzip.h | 323 |
1 files changed, 323 insertions, 0 deletions
@@ -0,0 +1,323 @@ +/* Lziprecover - Data recovery tool for lzipped files + Copyright (C) 2009, 2010, 2011 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 State + { + unsigned char st; + +public: + enum { states = 12 }; + State() throw() : st( 0 ) {} + unsigned char operator()() const throw() { return st; } + bool is_char() const throw() { return st < 7; } + + void set_char() throw() + { + static const unsigned char next[states] = + { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 }; + st = next[st]; + } + + void set_match() throw() + { + static const unsigned char next[states] = + { 7, 7, 7, 7, 7, 7, 7, 10, 10, 10, 10, 10 }; + st = next[st]; + } + + void set_rep() throw() + { + static const unsigned char next[states] = + { 8, 8, 8, 8, 8, 8, 8, 11, 11, 11, 11, 11 }; + st = next[st]; + } + + void set_short_rep() throw() + { + static const unsigned char next[states] = + { 9, 9, 9, 9, 9, 9, 9, 11, 11, 11, 11, 11 }; + st = next[st]; + } + }; + + +enum { + min_dictionary_bits = 12, + min_dictionary_size = 1 << min_dictionary_bits, + max_dictionary_bits = 29, + max_dictionary_size = 1 << max_dictionary_bits, + literal_context_bits = 3, + pos_state_bits = 2, + pos_states = 1 << pos_state_bits, + pos_state_mask = pos_states - 1, + + dis_slot_bits = 6, + start_dis_model = 4, + end_dis_model = 14, + modeled_distances = 1 << (end_dis_model / 2), + 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, + + max_dis_states = 4 }; + +inline int get_dis_state( int len ) throw() + { + len -= min_match_len; + if( len >= max_dis_states ) len = max_dis_states - 1; + return len; + } + + +enum { bit_model_move_bits = 5, + bit_model_total_bits = 11, + bit_model_total = 1 << bit_model_total_bits }; + +struct Bit_model + { + unsigned int probability; + Bit_model() throw() : probability( bit_model_total / 2 ) {} + }; + + +class Pretty_print + { + const char * const stdin_name; + unsigned int longest_name; + const int verbosity_; + std::string name_; + mutable bool first_post; + +public: + Pretty_print( const std::vector< std::string > & filenames, const int v ) + : stdin_name( "(stdin)" ), longest_name( 0 ), verbosity_( v ), + first_post( false ) + { + const unsigned int stdin_name_len = std::strlen( stdin_name ); + for( unsigned int i = 0; i < filenames.size(); ++i ) + { + const std::string & s = filenames[i]; + const unsigned int len = ( ( s == "-" ) ? stdin_name_len : s.size() ); + if( len > longest_name ) 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; + first_post = true; + } + + void reset() const throw() { if( name_.size() ) first_post = true; } + const char * name() const throw() { return name_.c_str(); } + int verbosity() const throw() { return verbosity_; } + void operator()( const char * const msg = 0 ) const throw(); + }; + + +class CRC32 + { + uint32_t data[256]; // Table of CRCs of all 8-bit messages. + +public: + CRC32() + { + for( unsigned int n = 0; n < 256; ++n ) + { + unsigned int 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 throw() { return data[byte]; } + void update( uint32_t & crc, const uint8_t byte ) const throw() + { crc = data[(crc^byte)&0xFF] ^ ( crc >> 8 ); } + void update( uint32_t & crc, const uint8_t * const buffer, const int size ) const throw() + { + for( int i = 0; i < size; ++i ) + crc = data[(crc^buffer[i])&0xFF] ^ ( crc >> 8 ); + } + }; + +extern const CRC32 crc32; + + +inline int real_bits( const int value ) throw() + { + int bits = 0; + for( int i = 1, mask = 1; mask > 0; ++i, mask <<= 1 ) + if( value & mask ) bits = i; + return bits; + } + +const uint8_t magic_string[4] = { 'L', 'Z', 'I', 'P' }; + +struct File_header + { + uint8_t data[6]; // 0-3 magic bytes + // 4 version + // 5 coded_dict_size + enum { size = 6 }; + + void set_magic() throw() + { std::memcpy( data, magic_string, 4 ); data[4] = 1; } + + bool verify_magic() const throw() + { return ( std::memcmp( data, magic_string, 4 ) == 0 ); } + + uint8_t version() const throw() { return data[4]; } + bool verify_version() const throw() { return ( data[4] <= 1 ); } + + int dictionary_size() const throw() + { + int sz = ( 1 << ( data[5] & 0x1F ) ); + if( sz > min_dictionary_size && sz <= max_dictionary_size ) + sz -= ( sz / 16 ) * ( ( data[5] >> 5 ) & 0x07 ); + return sz; + } + + bool dictionary_size( const int sz ) throw() + { + if( sz >= min_dictionary_size && sz <= max_dictionary_size ) + { + data[5] = real_bits( sz - 1 ); + if( sz > min_dictionary_size ) + { + const int base_size = 1 << data[5]; + const int wedge = base_size / 16; + for( int i = 7; i >= 1; --i ) + if( base_size - ( i * wedge ) >= sz ) + { data[5] |= ( i << 5 ); break; } + } + return true; + } + return false; + } + }; + + +struct File_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 + + static int size( const int version = 1 ) + { return ( ( version >= 1 ) ? 20 : 12 ); } + + uint32_t data_crc() const throw() + { + uint32_t tmp = 0; + for( int i = 3; i >= 0; --i ) { tmp <<= 8; tmp += data[i]; } + return tmp; + } + + void data_crc( uint32_t crc ) throw() + { for( int i = 0; i <= 3; ++i ) { data[i] = (uint8_t)crc; crc >>= 8; } } + + long long data_size() const throw() + { + long long tmp = 0; + for( int i = 11; i >= 4; --i ) { tmp <<= 8; tmp += data[i]; } + return tmp; + } + + void data_size( long long sz ) throw() + { + for( int i = 4; i <= 11; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } + } + + long long member_size() const throw() + { + long long tmp = 0; + for( int i = 19; i >= 12; --i ) { tmp <<= 8; tmp += data[i]; } + return tmp; + } + + void member_size( long long sz ) throw() + { + for( int i = 12; i <= 19; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } + } + }; + + +struct Error + { + const char * const msg; + Error( const char * const s ) throw() : msg( s ) {} + }; + + +#ifndef LLONG_MAX +#define LLONG_MAX 0x7FFFFFFFFFFFFFFFLL +#endif +#ifndef LLONG_MIN +#define LLONG_MIN (-LLONG_MAX - 1LL) +#endif +#ifndef ULLONG_MAX +#define ULLONG_MAX 0xFFFFFFFFFFFFFFFFULL +#endif + + +// defined in decoder.cc +int readblock( const int fd, uint8_t * const buf, const int size ) throw(); +int writeblock( const int fd, const uint8_t * const buf, const int size ) throw(); + +// defined in main.cc +extern int verbosity; +int open_instream( const std::string & name, struct stat * const in_statsp, + const bool to_stdout, const bool reg_only = false ) throw(); +int open_outstream_rw( const std::string & output_filename, + const bool force ) throw(); +void show_error( const char * const msg, const int errcode = 0, + const bool help = false ) throw(); +void internal_error( const char * const msg ); + +// defined in merge.cc +void cleanup_and_fail( const std::string & output_filename, + const int outfd, const int retval ) throw(); +bool copy_file( const int infd, const int outfd, + const long long size = LLONG_MAX ); +bool try_decompress( const int fd, const long long file_size, + long long * failure_posp = 0 ); +bool verify_header( const File_header & header ); +bool verify_single_member( const int fd, const long long file_size ); +int merge_files( const std::vector< std::string > & filenames, + const std::string & output_filename, const bool force ); + +// defined in repair.cc +int repair_file( const std::string & input_filename, + const std::string & output_filename, const bool force ); + +// defined in split.cc +int split_file( const std::string & input_filename, + const std::string & default_output_filename, const bool force ); |