diff options
Diffstat (limited to 'lzip.h')
| -rw-r--r-- | lzip.h | 246 |
1 files changed, 246 insertions, 0 deletions
@@ -0,0 +1,246 @@ +/* Plzip - A parallel compressor compatible with lzip + Copyright (C) 2009, 2010, 2011, 2012, 2013 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/>. +*/ + +enum { + min_dictionary_bits = 12, + min_dictionary_size = 1 << min_dictionary_bits, + max_dictionary_bits = 29, + max_dictionary_size = 1 << max_dictionary_bits, + min_member_size = 36 }; + + +class Pretty_print + { + std::string name_; + const char * const stdin_name; + unsigned longest_name; + mutable bool first_post; + +public: + explicit Pretty_print( const std::vector< std::string > & filenames ) + : stdin_name( "(stdin)" ), longest_name( 0 ), first_post( false ) + { + 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( 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 { if( name_.size() ) first_post = true; } + const char * name() const { return name_.c_str(); } + void operator()( const char * const msg = 0 ) const; + }; + + +inline int real_bits( unsigned value ) + { + int bits = 0; + while( value > 0 ) { value >>= 1; ++bits; } + return bits; + } + + +const uint8_t magic_string[4] = { 0x4C, 0x5A, 0x49, 0x50 }; // "LZIP" + +struct File_header + { + uint8_t data[6]; // 0-3 magic bytes + // 4 version + // 5 coded_dict_size + enum { size = 6 }; + + void set_magic() { std::memcpy( data, magic_string, 4 ); data[4] = 1; } + bool verify_magic() const + { return ( std::memcmp( data, magic_string, 4 ) == 0 ); } + + 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 int sz ) + { + 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 + + 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; } + } + }; + + +// defined in compress.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 ); +void xinit( pthread_mutex_t * const mutex ); +void xinit( pthread_cond_t * const cond ); +void xdestroy( pthread_mutex_t * const mutex ); +void xdestroy( pthread_cond_t * const cond ); +void xlock( pthread_mutex_t * const mutex ); +void xunlock( pthread_mutex_t * const mutex ); +void xwait( pthread_cond_t * const cond, pthread_mutex_t * const mutex ); +void xsignal( pthread_cond_t * const cond ); +void xbroadcast( pthread_cond_t * const cond ); +int compress( const int data_size, const int dictionary_size, + const int match_len_limit, int num_workers, + const int infd, const int outfd, + const Pretty_print & pp, const int debug_level ); + +// defined in file_index.cc +class File_index; + +// defined in dec_stdout.cc +int dec_stdout( const int num_workers, const int infd, const int outfd, + const Pretty_print & pp, const int debug_level, + const File_index & file_index ); + +// defined in dec_stream.cc +int dec_stream( const int num_workers, const int infd, const int outfd, + const Pretty_print & pp, const int debug_level, + const bool testing ); + +// defined in decompress.cc +int preadblock( const int fd, uint8_t * const buf, const int size, + const long long pos ); +int pwriteblock( const int fd, const uint8_t * const buf, const int size, + const long long pos ); +int decompress_read_error( struct LZ_Decoder * const decoder, + const Pretty_print & pp, const int worker_id ); +int decompress( int num_workers, const int infd, const int outfd, + const Pretty_print & pp, const int debug_level, + const bool testing, const bool infd_isreg ); + +// defined in main.cc +extern int verbosity; +void fatal( const int retval = 1 ); // terminate the program +void show_error( const char * const msg, const int errcode = 0, + const bool help = false ); +void internal_error( const char * const msg ); + + +class Slot_tally + { + const int num_slots; // total slots + int num_free; // remaining free slots + pthread_mutex_t mutex; + pthread_cond_t slot_av; // free slot available + + Slot_tally( const Slot_tally & ); // declared as private + void operator=( const Slot_tally & ); // declared as private + +public: + explicit Slot_tally( const int slots ) + : num_slots( slots ), num_free( slots ) + { xinit( &mutex ); xinit( &slot_av ); } + + ~Slot_tally() { xdestroy( &slot_av ); xdestroy( &mutex ); } + + bool all_free() { return ( num_free == num_slots ); } + + void get_slot() // wait for a free slot + { + xlock( &mutex ); + while( num_free <= 0 ) xwait( &slot_av, &mutex ); + --num_free; + xunlock( &mutex ); + } + + void leave_slot() // return a slot to the tally + { + xlock( &mutex ); + if( ++num_free == 1 ) xsignal( &slot_av ); // num_free was 0 + xunlock( &mutex ); + } + + void leave_slots( const int slots ) // return slots to the tally + { + xlock( &mutex ); + num_free += slots; + if( num_free == slots ) xsignal( &slot_av ); // num_free was 0 + xunlock( &mutex ); + } + }; |