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-rw-r--r--pdlzip.h162
1 files changed, 162 insertions, 0 deletions
diff --git a/pdlzip.h b/pdlzip.h
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+/* 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 );