diff options
Diffstat (limited to 'decoder.cc')
| -rw-r--r-- | decoder.cc | 162 |
1 files changed, 85 insertions, 77 deletions
@@ -38,71 +38,11 @@ #include "decoder.h" -const CRC32 crc32; - -// Copies up to `out_size' bytes to `out_buffer' and updates `get'. -// Returns the number of bytes copied. -int Circular_buffer::read_data( uint8_t * const out_buffer, const int out_size ) throw() - { - if( out_size < 0 ) return 0; - int size = 0; - if( get > put ) - { - size = std::min( buffer_size - get, out_size ); - if( size > 0 ) - { - std::memcpy( out_buffer, buffer + get, size ); - get += size; - if( get >= buffer_size ) get = 0; - } - } - if( get < put ) - { - const int size2 = std::min( put - get, out_size - size ); - if( size2 > 0 ) - { - std::memcpy( out_buffer + size, buffer + get, size2 ); - get += size2; - size += size2; - } - } - return size; - } - - -// Copies up to `in_size' bytes from `in_buffer' and updates `put'. -// Returns the number of bytes copied. -int Circular_buffer::write_data( const uint8_t * const in_buffer, const int in_size ) throw() - { - if( in_size < 0 ) return 0; - int size = 0; - if( put >= get ) - { - size = std::min( buffer_size - put - (get == 0), in_size ); - if( size > 0 ) - { - std::memcpy( buffer + put, in_buffer, size ); - put += size; - if( put >= buffer_size ) put = 0; - } - } - if( put < get ) - { - const int size2 = std::min( get - put - 1, in_size - size ); - if( size2 > 0 ) - { - std::memcpy( buffer + put, in_buffer + size, size2 ); - put += size2; - size += size2; - } - } - return size; - } - +const CRC32 Lzlib_namespace::crc32; // Seeks a member header and updates `get'. // Returns true if it finds a valid header. -bool Input_buffer::find_header() throw() +bool Range_decoder::find_header() throw() { while( get != put ) { @@ -110,10 +50,10 @@ bool Input_buffer::find_header() throw() { int g = get; File_header header; - for( unsigned int i = 0; i < sizeof header; ++i ) + for( int i = 0; i < File_header::size; ++i ) { if( g == put ) return false; // not enough data - ((uint8_t *)&header)[i] = buffer[g]; + header.data[i] = buffer[g]; if( ++g >= buffer_size ) g = 0; } if( header.verify() ) return true; @@ -127,36 +67,44 @@ bool Input_buffer::find_header() throw() // Returns true, fills `header', and updates `get' if `get' points to a // valid header. // Else returns false and leaves `get' unmodified. -bool Input_buffer::read_header( File_header & header ) throw() +bool Range_decoder::read_header( File_header & header ) throw() { int g = get; - for( unsigned int i = 0; i < sizeof header; ++i ) + for( int i = 0; i < File_header::size; ++i ) { if( g == put ) return false; // not enough data - ((uint8_t *)&header)[i] = buffer[g]; + header.data[i] = buffer[g]; if( ++g >= buffer_size ) g = 0; } - if( header.verify() ) { get = g; return true; } + if( header.verify() ) + { + get = g; + member_pos = File_header::size; + reload_pending = true; + return true; + } return false; } bool LZ_decoder::verify_trailer() { - bool error = false; File_trailer trailer; - const int trailer_size = trailer.size( format_version ); + const int trailer_size = File_trailer::size( member_version ); + const long long member_size = range_decoder.member_position() + trailer_size; + bool error = false; + for( int i = 0; i < trailer_size && !error; ++i ) { if( !range_decoder.finished() ) - ((uint8_t *)&trailer)[i] = range_decoder.get_byte(); - else error = true; + trailer.data[i] = range_decoder.get_byte(); + else { error = true; for( ; i < trailer_size; ++i ) trailer.data[i] = 0; } } - if( format_version == 0 ) trailer.member_size( member_position() ); + if( member_version == 0 ) trailer.member_size( member_size ); if( !range_decoder.code_is_zero() ) error = true; if( trailer.data_crc() != crc() ) error = true; if( trailer.data_size() != data_position() ) error = true; - if( trailer.member_size() != member_position() ) error = true; + if( trailer.member_size() != member_size ) error = true; return !error; } @@ -169,7 +117,7 @@ int LZ_decoder::decode_member() if( !range_decoder.try_reload() ) return 0; if( verify_trailer_pending ) { - if( range_decoder.available_bytes() < File_trailer::size( format_version ) && + if( range_decoder.available_bytes() < File_trailer::size( member_version ) && !range_decoder.at_stream_end() ) return 0; verify_trailer_pending = false; @@ -240,13 +188,13 @@ int LZ_decoder::decode_member() { rep0 += range_decoder.decode( direct_bits - dis_align_bits ) << dis_align_bits; rep0 += range_decoder.decode_tree_reversed( bm_align, dis_align_bits ); - if( rep0 == 0xFFFFFFFF ) // Marker found + if( rep0 == 0xFFFFFFFFU ) // Marker found { rep0 = rep0_saved; range_decoder.normalize(); if( len == min_match_len ) // End Of Stream marker { - if( range_decoder.available_bytes() < File_trailer::size( format_version ) && + if( range_decoder.available_bytes() < File_trailer::size( member_version ) && !range_decoder.at_stream_end() ) { verify_trailer_pending = true; return 0; } member_finished_ = true; @@ -269,3 +217,63 @@ int LZ_decoder::decode_member() } } } + + +// Copies up to `out_size' bytes to `out_buffer' and updates `get'. +// Returns the number of bytes copied. +int Circular_buffer::read_data( uint8_t * const out_buffer, const int out_size ) throw() + { + if( out_size < 0 ) return 0; + int size = 0; + if( get > put ) + { + size = std::min( buffer_size - get, out_size ); + if( size > 0 ) + { + std::memcpy( out_buffer, buffer + get, size ); + get += size; + if( get >= buffer_size ) get = 0; + } + } + if( get < put ) + { + const int size2 = std::min( put - get, out_size - size ); + if( size2 > 0 ) + { + std::memcpy( out_buffer + size, buffer + get, size2 ); + get += size2; + size += size2; + } + } + return size; + } + + +// Copies up to `in_size' bytes from `in_buffer' and updates `put'. +// Returns the number of bytes copied. +int Circular_buffer::write_data( const uint8_t * const in_buffer, const int in_size ) throw() + { + if( in_size < 0 ) return 0; + int size = 0; + if( put >= get ) + { + size = std::min( buffer_size - put - (get == 0), in_size ); + if( size > 0 ) + { + std::memcpy( buffer + put, in_buffer, size ); + put += size; + if( put >= buffer_size ) put = 0; + } + } + if( put < get ) + { + const int size2 = std::min( get - put - 1, in_size - size ); + if( size2 > 0 ) + { + std::memcpy( buffer + put, in_buffer + size, size2 ); + put += size2; + size += size2; + } + } + return size; + } |