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Diffstat (limited to 'pdlzip.h')
| -rw-r--r-- | pdlzip.h | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/pdlzip.h b/pdlzip.h new file mode 100644 index 0000000..604f508 --- /dev/null +++ b/pdlzip.h @@ -0,0 +1,162 @@ +/* Pdlzip - A data compressor based on the LZMA algorithm + Copyright (C) 2010 Antonio Diaz Diaz. + + This program is free software: you have unlimited permission + to copy, distribute and modify it. + + 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. +*/ + +enum { + min_dictionary_bits = 12, + min_dictionary_size = 1 << min_dictionary_bits, + max_dictionary_bits = 27, + max_dictionary_size = 1 << max_dictionary_bits, + literal_context_bits = 3, + pos_state_bits = 2, + + 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 }; + +typedef uint32_t CRC32[256]; // Table of CRCs of all 8-bit messages. + +extern CRC32 crc32; + +static inline void CRC32_init() + { + for( unsigned int n = 0; n < 256; ++n ) + { + unsigned int c = n; + for( int k = 0; k < 8; ++k ) + { if( c & 1 ) c = 0xEDB88320 ^ ( c >> 1 ); else c >>= 1; } + crc32[n] = c; + } + } + +static inline void CRC32_update_byte( uint32_t * crc, const uint8_t byte ) + { *crc = crc32[(*crc^byte)&0xFF] ^ ( *crc >> 8 ); } +static inline void CRC32_update_buf( uint32_t * crc, const uint8_t * const buffer, + const int size ) + { + for( int i = 0; i < size; ++i ) + *crc = crc32[(*crc^buffer[i])&0xFF] ^ ( *crc >> 8 ); + } + + +typedef uint8_t File_header[6]; // 0-3 magic bytes + // 4 version + // 5 coded_dict_size; + +static inline void Fh_set_magic( File_header header ) + { + const uint8_t magic_string[4] = { 'L', 'Z', 'I', 'P' }; + memcpy( header, magic_string, 4 ); + header[4] = 1; + } + +static inline bool Fh_verify_magic( const File_header header ) + { + const uint8_t magic_string[4] = { 'L', 'Z', 'I', 'P' }; + return ( memcmp( header, magic_string, 4 ) == 0 ); + } + +static inline uint8_t Fh_version( const File_header header ) + { return header[4]; } + +static inline bool Fh_verify_version( const File_header header ) + { return ( header[4] <= 1 ); } + +static inline int Fh_real_bits( const int value ) + { + int bits = 0; + for( int i = 1, mask = 1; mask > 0; ++i, mask <<= 1 ) + if( value & mask ) bits = i; + return bits; + } + +static inline int Fh_get_dictionary_size( const File_header header ) + { + int size = ( 1 << ( header[5] & 0x1F ) ); + if( size > min_dictionary_size && size <= max_dictionary_size ) + size -= ( size / 16 ) * ( ( header[5] >> 5 ) & 0x07 ); + return size; + } + +static inline bool Fh_set_dictionary_size( File_header header, const int size ) + { + if( size >= min_dictionary_size && size <= max_dictionary_size ) + { + header[5] = Fh_real_bits( size - 1 ); + if( size > min_dictionary_size ) + { + const int base_size = 1 << header[5]; + const int wedge = base_size / 16; + for( int i = 7; i >= 1; --i ) + if( base_size - ( i * wedge ) >= size ) + { header[5] |= ( i << 5 ); break; } + } + return true; + } + return false; + } + + +typedef uint8_t File_trailer[20]; + // 0-3 CRC32 of the uncompressed data + // 4-11 size of the uncompressed data + // 12-19 member size including header and trailer + +static inline int Ft_size( const int version ) + { return sizeof (File_trailer) - ( ( version >= 1 ) ? 0 : 8 ); } + +static inline uint32_t Ft_get_data_crc( const File_trailer trailer ) + { + uint32_t tmp = 0; + for( int i = 3; i >= 0; --i ) { tmp <<= 8; tmp += trailer[i]; } + return tmp; + } + +static inline void Ft_set_data_crc( File_trailer trailer, uint32_t crc ) + { for( int i = 0; i <= 3; ++i ) { trailer[i] = (uint8_t)crc; crc >>= 8; } } + +static inline long long Ft_get_data_size( const File_trailer trailer ) + { + long long tmp = 0; + for( int i = 11; i >= 4; --i ) { tmp <<= 8; tmp += trailer[i]; } + return tmp; + } + +static inline void Ft_set_data_size( File_trailer trailer, long long size ) + { + for( int i = 4; i <= 11; ++i ) { trailer[i] = (uint8_t)size; size >>= 8; } + } + +static inline long long Ft_get_member_size( const File_trailer trailer ) + { + long long tmp = 0; + for( int i = 19; i >= 12; --i ) { tmp <<= 8; tmp += trailer[i]; } + return tmp; + } + +static inline void Ft_set_member_size( File_trailer trailer, long long size ) + { + for( int i = 12; i <= 19; ++i ) { trailer[i] = (uint8_t)size; size >>= 8; } + } + + +extern int verbosity; + +void cleanup_and_fail( const int retval ); +void show_error( const char * const msg, const int errcode, const bool help ); +void internal_error( const char * const msg ); |