diff options
Diffstat (limited to 'lzip.h')
| -rw-r--r-- | lzip.h | 49 |
1 files changed, 28 insertions, 21 deletions
@@ -1,5 +1,5 @@ /* Lzlib - Compression library for the lzip format - Copyright (C) 2009-2015 Antonio Diaz Diaz. + Copyright (C) 2009-2016 Antonio Diaz Diaz. This library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -60,6 +60,7 @@ enum { 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, @@ -100,8 +101,8 @@ 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 * const p, const int size ) - { int i = 0; while( i < size ) p[i++] = 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 { @@ -183,6 +184,11 @@ 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 ); } + + static inline int real_bits( unsigned value ) { int bits = 0; @@ -204,6 +210,14 @@ static inline void Fh_set_magic( File_header data ) static inline bool Fh_verify_magic( const File_header data ) { return ( memcmp( data, magic_string, 4 ) == 0 ); } +/* detect truncated header */ +static inline bool Fh_verify_prefix( const File_header data, const int size ) + { + int i; for( i = 0; i < size && i < 4; ++i ) + if( data[i] != magic_string[i] ) return false; + return ( size > 0 ); + } + static inline uint8_t Fh_version( const File_header data ) { return data[4]; } @@ -220,31 +234,24 @@ static inline unsigned Fh_get_dictionary_size( const File_header data ) static inline bool Fh_set_dictionary_size( File_header data, const unsigned sz ) { - if( sz >= min_dictionary_size && sz <= max_dictionary_size ) + if( !isvalid_ds( sz ) ) return false; + data[5] = real_bits( sz - 1 ); + if( sz > min_dictionary_size ) { - data[5] = real_bits( sz - 1 ); - if( sz > min_dictionary_size ) - { - const unsigned base_size = 1 << data[5]; - const unsigned fraction = base_size / 16; - int i; - for( i = 7; i >= 1; --i ) - if( base_size - ( i * fraction ) >= sz ) - { data[5] |= ( i << 5 ); break; } - } - return true; + const unsigned base_size = 1 << data[5]; + const unsigned fraction = base_size / 16; + int i; + for( i = 7; i >= 1; --i ) + if( base_size - ( i * fraction ) >= sz ) + { data[5] |= ( i << 5 ); break; } } - return false; + return true; } static inline bool Fh_verify( const File_header data ) { if( Fh_verify_magic( data ) && Fh_verify_version( data ) ) - { - const unsigned dictionary_size = Fh_get_dictionary_size( data ); - return ( dictionary_size >= min_dictionary_size && - dictionary_size <= max_dictionary_size ); - } + return isvalid_ds( Fh_get_dictionary_size( data ) ); return false; } |