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-rw-r--r--lzip.h146
1 files changed, 0 insertions, 146 deletions
diff --git a/lzip.h b/lzip.h
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index d88e9c7..0000000
--- a/lzip.h
+++ /dev/null
@@ -1,146 +0,0 @@
-/* Tarlz - Archiver with multimember lzip compression
- Copyright (C) 2013-2019 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/>.
-*/
-
-#ifndef LZ_API_VERSION
-#define LZ_API_VERSION 1
-#endif
-
-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 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;
- }
- }
-
- void update_byte( uint32_t & crc, const uint8_t byte ) const
- { crc = data[(crc^byte)&0xFF] ^ ( crc >> 8 ); }
- };
-
-
-inline bool isvalid_ds( const unsigned dictionary_size )
- { return ( dictionary_size >= min_dictionary_size &&
- dictionary_size <= max_dictionary_size ); }
-
-
-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_dict_size
- enum { size = 6 };
-
- 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;
- }
- };
-
-
-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;
- }
-
- 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;
- }
-
- 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;
- }
-
- 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;
- }
- };
-
-
-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 extract.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 );