diff options
Diffstat (limited to 'lzip.h')
| -rw-r--r-- | lzip.h | 79 |
1 files changed, 36 insertions, 43 deletions
@@ -32,7 +32,7 @@ class State public: enum { states = 12 }; State() throw() : st( 0 ) {} - int operator()() const throw() { return st; } + unsigned char operator()() const throw() { return st; } bool is_char() const throw() { return st < 7; } void set_char() throw() @@ -118,7 +118,7 @@ public: { unsigned int c = n; for( int k = 0; k < 8; ++k ) - { if( c & 1 ) c = 0xEDB88320 ^ ( c >> 1 ); else c >>= 1; } + { if( c & 1 ) c = 0xEDB88320U ^ ( c >> 1 ); else c >>= 1; } data[n] = c; } } @@ -133,29 +133,27 @@ public: } }; -extern const CRC32 crc32; +namespace Lzlib_namespace { extern const CRC32 crc32; } +using Lzlib_namespace::crc32; const uint8_t magic_string[4] = { 'L', 'Z', 'I', 'P' }; struct File_header { - uint8_t magic[4]; - uint8_t version; - uint8_t coded_dict_size; + uint8_t data[6]; // 0-3 magic bytes + // 4 version + // 5 coded_dict_size + enum { size = 6 }; void set_magic() throw() - { std::memcpy( magic, magic_string, sizeof magic ); version = 1; } + { std::memcpy( data, magic_string, 4 ); data[4] = 1; } bool verify_magic() const throw() - { - return ( std::memcmp( magic, magic_string, sizeof magic ) == 0 ); - } + { return ( std::memcmp( data, magic_string, 4 ) == 0 ); } - bool verify_version() const throw() - { - return ( version <= 1 ); - } + uint8_t version() const throw() { return data[4]; } + bool verify_version() const throw() { return ( data[4] <= 1 ); } bool verify() const throw() { @@ -174,24 +172,24 @@ struct File_header int dictionary_size() const throw() { - int size = ( 1 << ( coded_dict_size & 0x1F ) ); - if( size > min_dictionary_size && size <= max_dictionary_size ) - size -= ( size / 16 ) * ( ( coded_dict_size >> 5 ) & 0x07 ); - return size; + 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 size ) throw() + bool dictionary_size( const int sz ) throw() { - if( size >= min_dictionary_size && size <= max_dictionary_size ) + if( sz >= min_dictionary_size && sz <= max_dictionary_size ) { - coded_dict_size = real_bits( size - 1 ); - if( size > min_dictionary_size ) + data[5] = real_bits( sz - 1 ); + if( sz > min_dictionary_size ) { - const int base_size = 1 << coded_dict_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 ) >= size ) - { coded_dict_size |= ( i << 5 ); break; } + if( base_size - ( i * wedge ) >= sz ) + { data[5] |= ( i << 5 ); break; } } return true; } @@ -202,50 +200,45 @@ struct File_header struct File_trailer { - uint8_t data_crc_[4]; // CRC32 of the uncompressed data - uint8_t data_size_[8]; // size of the uncompressed data - uint8_t member_size_[8]; // member size including header and 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 ) - { return sizeof (File_trailer) - ( ( version >= 1 ) ? 0 : 8 ); } + 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_crc_[i]; } + 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 < 4; ++i ) - { data_crc_[i] = (uint8_t)crc; crc >>= 8; } - } + { 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 = 7; i >= 0; --i ) { tmp <<= 8; tmp += data_size_[i]; } + for( int i = 11; i >= 4; --i ) { tmp <<= 8; tmp += data[i]; } return tmp; } - void data_size( long long size ) throw() + void data_size( long long sz ) throw() { - for( int i = 0; i < 8; ++i ) - { data_size_[i] = (uint8_t)size; size >>= 8; } + 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 = 7; i >= 0; --i ) { tmp <<= 8; tmp += member_size_[i]; } + for( int i = 19; i >= 12; --i ) { tmp <<= 8; tmp += data[i]; } return tmp; } - void member_size( long long size ) throw() + void member_size( long long sz ) throw() { - for( int i = 0; i < 8; ++i ) - { member_size_[i] = (uint8_t)size; size >>= 8; } + for( int i = 12; i <= 19; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } } }; |