Initial commit

Unity Studio/7zip/Compress/LZ/LzOutWindow.cs

@@ -0,0 +1,110 @@
+// LzOutWindow.cs
+
+namespace SevenZip.Compression.LZ
+{
+	public class OutWindow
+	{
+		byte[] _buffer = null;
+		uint _pos;
+		uint _windowSize = 0;
+		uint _streamPos;
+		System.IO.Stream _stream;
+
+		public uint TrainSize = 0;
+
+		public void Create(uint windowSize)
+		{
+			if (_windowSize != windowSize)
+			{
+				// System.GC.Collect();
+				_buffer = new byte[windowSize];
+			}
+			_windowSize = windowSize;
+			_pos = 0;
+			_streamPos = 0;
+		}
+
+		public void Init(System.IO.Stream stream, bool solid)
+		{
+			ReleaseStream();
+			_stream = stream;
+			if (!solid)
+			{
+				_streamPos = 0;
+				_pos = 0;
+				TrainSize = 0;
+			}
+		}
+	
+		public bool Train(System.IO.Stream stream)
+		{
+			long len = stream.Length;
+			uint size = (len < _windowSize) ? (uint)len : _windowSize;
+			TrainSize = size;
+			stream.Position = len - size;
+			_streamPos = _pos = 0;
+			while (size > 0)
+			{
+				uint curSize = _windowSize - _pos;
+				if (size < curSize)
+					curSize = size;
+				int numReadBytes = stream.Read(_buffer, (int)_pos, (int)curSize);
+				if (numReadBytes == 0)
+					return false;
+				size -= (uint)numReadBytes;
+				_pos += (uint)numReadBytes;
+				_streamPos += (uint)numReadBytes;
+				if (_pos == _windowSize)
+					_streamPos = _pos = 0;
+			}
+			return true;
+		}
+
+		public void ReleaseStream()
+		{
+			Flush();
+			_stream = null;
+		}
+
+		public void Flush()
+		{
+			uint size = _pos - _streamPos;
+			if (size == 0)
+				return;
+			_stream.Write(_buffer, (int)_streamPos, (int)size);
+			if (_pos >= _windowSize)
+				_pos = 0;
+			_streamPos = _pos;
+		}
+
+		public void CopyBlock(uint distance, uint len)
+		{
+			uint pos = _pos - distance - 1;
+			if (pos >= _windowSize)
+				pos += _windowSize;
+			for (; len > 0; len--)
+			{
+				if (pos >= _windowSize)
+					pos = 0;
+				_buffer[_pos++] = _buffer[pos++];
+				if (_pos >= _windowSize)
+					Flush();
+			}
+		}
+
+		public void PutByte(byte b)
+		{
+			_buffer[_pos++] = b;
+			if (_pos >= _windowSize)
+				Flush();
+		}
+
+		public byte GetByte(uint distance)
+		{
+			uint pos = _pos - distance - 1;
+			if (pos >= _windowSize)
+				pos += _windowSize;
+			return _buffer[pos];
+		}
+	}
+}