diff options
Diffstat (limited to 'lzip.h')
| -rw-r--r-- | lzip.h | 80 |
1 files changed, 38 insertions, 42 deletions
@@ -1,20 +1,20 @@ -/* Lzlib - Compression library for the lzip format - Copyright (C) 2009-2019 Antonio Diaz Diaz. +/* 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: + 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. + 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. + 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. + 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 @@ -35,17 +35,13 @@ 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 ); } - + { return ( st < 7 ) ? 7 : 10; } static inline State St_set_rep( const State st ) - { return ( ( st < 7 ) ? 8 : 11 ); } - + { return ( st < 7 ) ? 8 : 11; } static inline State St_set_short_rep( const State st ) - { return ( ( st < 7 ) ? 9 : 11 ); } + { return ( st < 7 ) ? 9 : 11; } enum { @@ -83,7 +79,7 @@ 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 ) ); } + { return prev_byte >> ( 8 - literal_context_bits ); } enum { bit_model_move_bits = 5, @@ -168,6 +164,7 @@ static const uint32_t crc32[256] = 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 ) @@ -181,8 +178,8 @@ static inline void CRC32_update_buf( uint32_t * const crc, static inline bool isvalid_ds( const unsigned dictionary_size ) - { return ( dictionary_size >= min_dictionary_size && - dictionary_size <= max_dictionary_size ); } + { return dictionary_size >= min_dictionary_size && + dictionary_size <= max_dictionary_size; } static inline int real_bits( unsigned value ) @@ -195,43 +192,43 @@ static inline int real_bits( unsigned value ) static const uint8_t lzip_magic[4] = { 0x4C, 0x5A, 0x49, 0x50 }; /* "LZIP" */ -typedef uint8_t Lzip_header[6]; /* 0-3 magic bytes */ - /* 4 version */ - /* 5 coded_dict_size */ 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_verify_magic( const Lzip_header data ) - { return ( memcmp( data, lzip_magic, 4 ) == 0 ); } +static inline bool Lh_check_magic( const Lzip_header data ) + { return memcmp( data, lzip_magic, 4 ) == 0; } /* detect (truncated) header */ -static inline bool Lh_verify_prefix( const Lzip_header data, const int sz ) +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 ); + return sz > 0; } /* detect corrupt header */ -static inline bool Lh_verify_corrupt( const Lzip_header data ) +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 ); + return matches > 1 && matches < 4; } static inline uint8_t Lh_version( const Lzip_header data ) { return data[4]; } -static inline bool Lh_verify_version( const Lzip_header data ) - { return ( data[4] == 1 ); } +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 ) ); + unsigned sz = 1 << ( data[5] & 0x1F ); if( sz > min_dictionary_size ) sz -= ( sz / 16 ) * ( ( data[5] >> 5 ) & 7 ); return sz; @@ -248,24 +245,23 @@ static inline bool Lh_set_dictionary_size( Lzip_header data, const unsigned sz ) unsigned i; for( i = 7; i >= 1; --i ) if( base_size - ( i * fraction ) >= sz ) - { data[5] |= ( i << 5 ); break; } + { data[5] |= i << 5; break; } } return true; } -static inline bool Lh_verify( const Lzip_header data ) +static inline bool Lh_check( const Lzip_header data ) { - if( Lh_verify_magic( data ) && Lh_verify_version( data ) ) - return isvalid_ds( Lh_get_dictionary_size( data ) ); - return false; + return Lh_check_magic( data ) && Lh_check_version( data ) && + isvalid_ds( Lh_get_dictionary_size( data ) ); } -typedef uint8_t Lzip_trailer[20]; +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 */ -enum { Lt_size = 20 }; static inline unsigned Lt_get_data_crc( const Lzip_trailer data ) { |