private async Task <ChunkBytes> Compress(ChunkBytes data)
{
var result = await Pool.GetAsync();
using (MemoryStream memStream = new MemoryStream(result.Bytes))
{
using (GZipStream gzipStream = new GZipStream(memStream, CompressionLevel.Optimal, leaveOpen: true))
await gzipStream.WriteAsync(data.Bytes, 0, data.Length);
result.Length = (int)memStream.Position;
}
return(result);
}
private async Task <ChunkBytes> Decompress(ChunkBytes data, int offset = 0)
{
var result = await Pool.GetAsync();
using (MemoryStream memStream = new MemoryStream(result.Bytes))
{
using (MemoryStream input = new MemoryStream(data.Bytes, offset, data.Length - offset))
using (GZipStream gzipStream = new GZipStream(input, CompressionMode.Decompress))
await gzipStream.CopyToAsync(memStream);
result.Length = (int)memStream.Position;
}
return(result);
}
private async Task <ChunkBytes> CryptoTransform(ChunkBytes data, ICryptoTransform transform)
{
var result = await Pool.GetAsync();
using (var memoryStream = new MemoryStream(result.Bytes))
{
using (var cryptoStream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write))
{
await cryptoStream.WriteAsync(data.Bytes, 0, data.Length);
cryptoStream.FlushFinalBlock();
result.Length = (int)memoryStream.Position;
}
}
return(result);
}
private Task <ChunkBytes> Decrypt(ChunkBytes data)
{
return(CryptoTransform(data, rijndaelAlgorithm.Value.CreateDecryptor()));
}
private static string MD5FromBytes(ChunkBytes data)
{
using (var md5 = MD5.Create())
using (var stream = new MemoryStream(data.Bytes, 0, data.Length))
return(BitConverter.ToString(md5.ComputeHash(stream)).Replace("-", "").ToLower());
}
public async Task CompressAndEncrypt(
Stream streamSource, Stream streamDestination,
CancellationTokenSource cts = null)
{
cts = cts ?? new CancellationTokenSource();
var compressorOptions = new ExecutionDataflowBlockOptions
{
MaxDegreeOfParallelism = Environment.ProcessorCount,
BoundedCapacity = _boundedCapacity,
CancellationToken = cts.Token
};
var inputBuffer = new BufferBlock <CompressingDetails>(
new DataflowBlockOptions
{
CancellationToken = cts.Token,
BoundedCapacity = _boundedCapacity
});
var compressor = new TransformBlock <CompressingDetails, CompressedDetails>(
async details =>
{
ChunkBytes compressedData = await Compress(details.Bytes);
await Pool.PutAsync(details.Bytes);
return(new CompressedDetails
{
Bytes = compressedData,
ChunkSize = details.ChunkSize,
Sequence = details.Sequence,
CompressedDataSize = new ChunkBytes(BitConverter.GetBytes(compressedData.Length))
});
}, compressorOptions);
var encryptor = new TransformBlock <CompressedDetails, EncryptDetails>(
async details =>
{
var data = await CombineByteArrays(details.CompressedDataSize, details.ChunkSize, details.Bytes);
await Pool.PutAsync(details.Bytes);
var encryptedData = await Encrypt(data);
await Pool.PutAsync(data);
return(new EncryptDetails
{
Bytes = encryptedData,
Sequence = details.Sequence,
EncryptedDataSize = new ChunkBytes(BitConverter.GetBytes(encryptedData.Length))
});
}, compressorOptions);
var asOrderedAgent = Agent.Start((new Dictionary <int, EncryptDetails>(), 0),
async((Dictionary <int, EncryptDetails>, int)state, EncryptDetails msg) =>
{
(Dictionary <int, EncryptDetails> details, int lastIndexProc) = state;
details.Add(msg.Sequence, msg);
while (details.ContainsKey(lastIndexProc + 1))
{
msg = details[lastIndexProc + 1];
await streamDestination.WriteAsync(msg.EncryptedDataSize.Bytes, 0, msg.EncryptedDataSize.Length);
await streamDestination.WriteAsync(msg.Bytes.Bytes, 0, msg.Bytes.Length);
await Pool.PutAsync(msg.Bytes);
lastIndexProc = msg.Sequence;
details.Remove(lastIndexProc);
}
return(details, lastIndexProc);
}, cts);
