GQ_Communicate/GQ_VR/Assets/Best HTTP/Source/Decompression/GZipDecompressor.cs

95 lines
3.2 KiB
C#

using System;
using BestHTTP.Extensions;
using BestHTTP.PlatformSupport.Memory;
namespace BestHTTP.Decompression
{
public sealed class GZipDecompressor : IDecompressor
{
private BufferPoolMemoryStream decompressorInputStream;
private BufferPoolMemoryStream decompressorOutputStream;
private Zlib.GZipStream decompressorStream;
private int MinLengthToDecompress = 256;
public GZipDecompressor(int minLengthToDecompress)
{
this.MinLengthToDecompress = minLengthToDecompress;
}
private void CloseDecompressors()
{
if (decompressorStream != null)
decompressorStream.Dispose();
decompressorStream = null;
if (decompressorInputStream != null)
decompressorInputStream.Dispose();
decompressorInputStream = null;
if (decompressorOutputStream != null)
decompressorOutputStream.Dispose();
decompressorOutputStream = null;
}
public DecompressedData Decompress(byte[] data, int offset, int count, bool forceDecompress = false, bool dataCanBeLarger = false)
{
if (decompressorInputStream == null)
decompressorInputStream = new BufferPoolMemoryStream(count);
if (data != null)
decompressorInputStream.Write(data, offset, count);
if (!forceDecompress && decompressorInputStream.Length < MinLengthToDecompress)
return new DecompressedData(null, 0);
decompressorInputStream.Position = 0;
if (decompressorStream == null)
{
decompressorStream = new Zlib.GZipStream(decompressorInputStream,
Zlib.CompressionMode.Decompress,
Zlib.CompressionLevel.Default,
true);
decompressorStream.FlushMode = Zlib.FlushType.Sync;
}
if (decompressorOutputStream == null)
decompressorOutputStream = new BufferPoolMemoryStream();
decompressorOutputStream.SetLength(0);
byte[] copyBuffer = BufferPool.Get(1024, true);
int readCount;
int sumReadCount = 0;
while ((readCount = decompressorStream.Read(copyBuffer, 0, copyBuffer.Length)) != 0)
{
decompressorOutputStream.Write(copyBuffer, 0, readCount);
sumReadCount += readCount;
}
BufferPool.Release(copyBuffer);
// If no read is done (returned with any data) don't zero out the input stream, as it would delete any not yet used data.
if (sumReadCount > 0)
decompressorStream.SetLength(0);
byte[] result = decompressorOutputStream.ToArray(dataCanBeLarger);
return new DecompressedData(result, dataCanBeLarger ? (int)decompressorOutputStream.Length : result.Length);
}
~GZipDecompressor()
{
Dispose();
}
public void Dispose()
{
CloseDecompressors();
GC.SuppressFinalize(this);
}
}
}