ToDynamicFrameSubject(this Socket socket, ISimpleFrameEncoder encoder, IDynamicFrameDecoder decoder,
SyncBufManager bufferManager, CancellationToken token)
{
return(Subject.Create <DisposableValue <ArraySegment <byte> >, DisposableValue <ArraySegment <byte> > >(
socket.ToFrameClientObserver(encoder, token, bufferManager),
socket.ToDynamicFrameObservable(bufferManager, decoder)));
}
public static IObservable <DisposableValue <ArraySegment <byte> > > ToDynamicFrameObservable(this Socket socket,
SyncBufManager bufferManager, IDynamicFrameDecoder decoder)
{
return(Observable.Create <DisposableValue <ArraySegment <byte> > >(async(observer, token) =>
{
try
{
var state = decoder.InitState();
byte[] leftoverBuf = null;
//rider suggestion is buggy: this variable must declare outside the loop in the case when receive length is zero
int leftoverCount = 0;
while (!token.IsCancellationRequested)
{
byte[] bufferArray;
int startIdx;
if (leftoverBuf != null)
{
bufferArray = leftoverBuf;
startIdx = leftoverCount;
leftoverBuf = null;
}
else
{
bufferArray = bufferManager.TakeBuffer(decoder.BufferSize);
startIdx = 0;
}
var pair = await socket.ReceiveDynamicFrame(state, bufferArray, startIdx, decoder, token);
var receiveLen = pair.Item1;
leftoverCount = pair.Item2;
if (receiveLen == 0) //no data received, and leftoverCount should be zero
{
var dropFrameStrategy = decoder.CheckDropFrame(state, bufferArray, startIdx);
switch (dropFrameStrategy)
{
case DropFrameStrategyEnum.DropAndClose:
//reclaim buffer array
bufferManager.ReturnBuffer(bufferArray);
break;
case DropFrameStrategyEnum.DropAndRestart:
//reclaim buffer array
bufferManager.ReturnBuffer(bufferArray);
continue;
case DropFrameStrategyEnum.KeepAndContinue:
//keep last received data
leftoverBuf = bufferArray;
leftoverCount = startIdx;
continue;
}
if (dropFrameStrategy == DropFrameStrategyEnum.DropAndClose)
{
break;
}
}
if (receiveLen == -1) //overflow,TODO support extensible frame in future
{
//reclaim buffer array
bufferManager.ReturnBuffer(bufferArray);
break;
}
//copy leftover
if (leftoverCount > 0)
{
leftoverBuf = bufferManager.TakeBuffer(decoder.BufferSize);
Buffer.BlockCopy(bufferArray, receiveLen - leftoverCount, leftoverBuf, 0, leftoverCount);
}
var arraySegment = decoder.BuildFrame(state, bufferArray, receiveLen, leftoverCount);
observer.OnNext(
new DisposableValue <ArraySegment <byte> >(arraySegment,
Disposable.Create(() => bufferManager.ReturnBuffer(bufferArray))));
}
observer.OnCompleted();
socket.Close();
}
catch (Exception error)
{
observer.OnError(error);
}
}));
}
