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Diffstat (limited to 'lzip.h')
| -rw-r--r-- | lzip.h | 294 |
1 files changed, 294 insertions, 0 deletions
@@ -0,0 +1,294 @@ +/* Lzlib - Compression library for the lzip format + Copyright (C) 2009-2024 Antonio Diaz Diaz. + + This library is free software. Redistribution and use in source and + binary forms, with or without modification, are permitted provided + that the following conditions are met: + + 1. Redistributions of source code must retain the above copyright + notice, this list of conditions, and the following disclaimer. + + 2. Redistributions in binary form must reproduce the above copyright + notice, this list of conditions, and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + This library 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. +*/ + +#ifndef max + #define max(x,y) ((x) >= (y) ? (x) : (y)) +#endif +#ifndef min + #define min(x,y) ((x) <= (y) ? (x) : (y)) +#endif + +typedef int State; + +enum { states = 12 }; + +static inline bool St_is_char( const State st ) { return st < 7; } + +static inline State St_set_char( const State st ) + { + static const State next[states] = { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 }; + return next[st]; + } +static inline State St_set_char_rep() { return 8; } +static inline State St_set_match( const State st ) + { return ( st < 7 ) ? 7 : 10; } +static inline State St_set_rep( const State st ) + { return ( st < 7 ) ? 8 : 11; } +static inline State St_set_short_rep( const State st ) + { return ( st < 7 ) ? 9 : 11; } + + +enum { + min_dictionary_bits = 12, + min_dictionary_size = 1 << min_dictionary_bits, /* >= modeled_distances */ + max_dictionary_bits = 29, + max_dictionary_size = 1 << max_dictionary_bits, + literal_context_bits = 3, + literal_pos_state_bits = 0, /* not used */ + pos_state_bits = 2, + pos_states = 1 << pos_state_bits, + pos_state_mask = pos_states - 1, + + len_states = 4, + dis_slot_bits = 6, + start_dis_model = 4, + end_dis_model = 14, + modeled_distances = 1 << (end_dis_model / 2), /* 128 */ + dis_align_bits = 4, + dis_align_size = 1 << dis_align_bits, + + 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 }; + +static inline int get_len_state( const int len ) + { return min( len - min_match_len, len_states - 1 ); } + +static inline int get_lit_state( const uint8_t prev_byte ) + { return prev_byte >> ( 8 - literal_context_bits ); } + + +enum { bit_model_move_bits = 5, + bit_model_total_bits = 11, + bit_model_total = 1 << bit_model_total_bits }; + +typedef int Bit_model; + +static inline void Bm_init( Bit_model * const probability ) + { *probability = bit_model_total / 2; } + +static inline void Bm_array_init( Bit_model bm[], const int size ) + { int i; for( i = 0; i < size; ++i ) Bm_init( &bm[i] ); } + +struct Len_model + { + Bit_model choice1; + Bit_model choice2; + Bit_model bm_low[pos_states][len_low_symbols]; + Bit_model bm_mid[pos_states][len_mid_symbols]; + Bit_model bm_high[len_high_symbols]; + }; + +static inline void Lm_init( struct Len_model * const lm ) + { + Bm_init( &lm->choice1 ); + Bm_init( &lm->choice2 ); + Bm_array_init( lm->bm_low[0], pos_states * len_low_symbols ); + Bm_array_init( lm->bm_mid[0], pos_states * len_mid_symbols ); + Bm_array_init( lm->bm_high, len_high_symbols ); + } + + +/* Table of CRCs of all 8-bit messages. */ +static const uint32_t crc32[256] = + { + 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, + 0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, + 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2, + 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, + 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, + 0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, + 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C, + 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59, + 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, + 0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, + 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106, + 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433, + 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, + 0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, + 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950, + 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65, + 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, + 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, + 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA, + 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F, + 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, + 0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, + 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84, + 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1, + 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, + 0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, + 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E, + 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B, + 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, + 0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, + 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28, + 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D, + 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, + 0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, + 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242, + 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777, + 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, + 0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, + 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC, + 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, + 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, + 0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, + 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D }; + + +static inline void CRC32_update_byte( uint32_t * const crc, const uint8_t byte ) + { *crc = crc32[(*crc^byte)&0xFF] ^ ( *crc >> 8 ); } + +/* about as fast as it is possible without messing with endianness */ +static inline void CRC32_update_buf( uint32_t * const crc, + const uint8_t * const buffer, + const int size ) + { + int i; + uint32_t c = *crc; + for( i = 0; i < size; ++i ) + c = crc32[(c^buffer[i])&0xFF] ^ ( c >> 8 ); + *crc = c; + } + + +static inline bool isvalid_ds( const unsigned dictionary_size ) + { return dictionary_size >= min_dictionary_size && + dictionary_size <= max_dictionary_size; } + + +static inline int real_bits( unsigned value ) + { + int bits = 0; + while( value > 0 ) { value >>= 1; ++bits; } + return bits; + } + + +static const uint8_t lzip_magic[4] = { 0x4C, 0x5A, 0x49, 0x50 }; /* "LZIP" */ + +enum { Lh_size = 6 }; +typedef uint8_t Lzip_header[Lh_size]; /* 0-3 magic bytes */ + /* 4 version */ + /* 5 coded dictionary size */ + +static inline void Lh_set_magic( Lzip_header data ) + { memcpy( data, lzip_magic, 4 ); data[4] = 1; } + +static inline bool Lh_check_magic( const Lzip_header data ) + { return memcmp( data, lzip_magic, 4 ) == 0; } + +/* detect (truncated) header */ +static inline bool Lh_check_prefix( const Lzip_header data, const int sz ) + { + int i; for( i = 0; i < sz && i < 4; ++i ) + if( data[i] != lzip_magic[i] ) return false; + return sz > 0; + } + +/* detect corrupt header */ +static inline bool Lh_check_corrupt( const Lzip_header data ) + { + int matches = 0; + int i; for( i = 0; i < 4; ++i ) + if( data[i] == lzip_magic[i] ) ++matches; + return matches > 1 && matches < 4; + } + +static inline uint8_t Lh_version( const Lzip_header data ) + { return data[4]; } + +static inline bool Lh_check_version( const Lzip_header data ) + { return data[4] == 1; } + +static inline unsigned Lh_get_dictionary_size( const Lzip_header data ) + { + unsigned sz = 1 << ( data[5] & 0x1F ); + if( sz > min_dictionary_size ) + sz -= ( sz / 16 ) * ( ( data[5] >> 5 ) & 7 ); + return sz; + } + +static inline bool Lh_set_dictionary_size( Lzip_header data, const unsigned sz ) + { + if( !isvalid_ds( sz ) ) return false; + data[5] = real_bits( sz - 1 ); + if( sz > min_dictionary_size ) + { + const unsigned base_size = 1 << data[5]; + const unsigned fraction = base_size / 16; + unsigned i; + for( i = 7; i >= 1; --i ) + if( base_size - ( i * fraction ) >= sz ) + { data[5] |= i << 5; break; } + } + return true; + } + +static inline bool Lh_check( const Lzip_header data ) + { + return Lh_check_magic( data ) && Lh_check_version( data ) && + isvalid_ds( Lh_get_dictionary_size( data ) ); + } + + +enum { Lt_size = 20 }; +typedef uint8_t Lzip_trailer[Lt_size]; + /* 0-3 CRC32 of the uncompressed data */ + /* 4-11 size of the uncompressed data */ + /* 12-19 member size including header and trailer */ + +static inline unsigned Lt_get_data_crc( const Lzip_trailer data ) + { + unsigned tmp = 0; + int i; for( i = 3; i >= 0; --i ) { tmp <<= 8; tmp += data[i]; } + return tmp; + } + +static inline void Lt_set_data_crc( Lzip_trailer data, unsigned crc ) + { int i; for( i = 0; i <= 3; ++i ) { data[i] = (uint8_t)crc; crc >>= 8; } } + +static inline unsigned long long Lt_get_data_size( const Lzip_trailer data ) + { + unsigned long long tmp = 0; + int i; for( i = 11; i >= 4; --i ) { tmp <<= 8; tmp += data[i]; } + return tmp; + } + +static inline void Lt_set_data_size( Lzip_trailer data, unsigned long long sz ) + { int i; for( i = 4; i <= 11; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } } + +static inline unsigned long long Lt_get_member_size( const Lzip_trailer data ) + { + unsigned long long tmp = 0; + int i; for( i = 19; i >= 12; --i ) { tmp <<= 8; tmp += data[i]; } + return tmp; + } + +static inline void Lt_set_member_size( Lzip_trailer data, unsigned long long sz ) + { int i; for( i = 12; i <= 19; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } } |