1 // LZ.OutWindow

     2 

     3 package SevenZip.Compression.LZ;

     4 

     5 import java.io.IOException;

     6 

     7 public class OutWindow

     8 {

     9 	byte[] _buffer;

    10 	int _pos;

    11 	int _windowSize = 0;

    12 	int _streamPos;

    13 	java.io.OutputStream _stream;

    14 	

    15 	public void Create(int windowSize)

    16 	{

    17 		if (_buffer == null || _windowSize != windowSize)

    18 			_buffer = new byte[windowSize];

    19 		_windowSize = windowSize;

    20 		_pos = 0;

    21 		_streamPos = 0;

    22 	}

    23 	

    24 	public void SetStream(java.io.OutputStream stream) throws IOException

    25 	{

    26 		ReleaseStream();

    27 		_stream = stream;

    28 	}

    29 	

    30 	public void ReleaseStream() throws IOException

    31 	{

    32 		Flush();

    33 		_stream = null;

    34 	}

    35 	

    36 	public void Init(boolean solid)

    37 	{

    38 		if (!solid)

    39 		{

    40 			_streamPos = 0;

    41 			_pos = 0;

    42 		}

    43 	}

    44 	

    45 	public void Flush() throws IOException

    46 	{

    47 		int size = _pos - _streamPos;

    48 		if (size == 0)

    49 			return;

    50 		_stream.write(_buffer, _streamPos, size);

    51 		if (_pos >= _windowSize)

    52 			_pos = 0;

    53 		_streamPos = _pos;

    54 	}

    55 	

    56 	public void CopyBlock(int distance, int len) throws IOException

    57 	{

    58 		int pos = _pos - distance - 1;

    59 		if (pos < 0)

    60 			pos += _windowSize;

    61 		for (; len != 0; len--)

    62 		{

    63 			if (pos >= _windowSize)

    64 				pos = 0;

    65 			_buffer[_pos++] = _buffer[pos++];

    66 			if (_pos >= _windowSize)

    67 				Flush();

    68 		}

    69 	}

    70 	

    71 	public void PutByte(byte b) throws IOException

    72 	{

    73 		_buffer[_pos++] = b;

    74 		if (_pos >= _windowSize)

    75 			Flush();

    76 	}

    77 	

    78 	public byte GetByte(int distance)

    79 	{

    80 		int pos = _pos - distance - 1;

    81 		if (pos < 0)

    82 			pos += _windowSize;

    83 		return _buffer[pos];

    84 	}

    85 }