private Task SendAsync(bool isBinary, byte[] bytes, int offset, int length, CancellationToken cancellationToken)
{
var task = TaskAsyncHelper.Empty;
var max = MaxFrameDataLength;
var opcode = isBinary ? WebSocketOpcode.Binary : WebSocketOpcode.Text;
while (length > 0)
{
var size = Math.Min(length, max);
length -= size;
var frame = new WebSocketClientFrame
{
Opcode = opcode,
IsFin = length == 0,
};
frame.Payload = new WebSocketPayload(frame, bytes, offset, size);
offset += size;
opcode = WebSocketOpcode.Continuation;
task = task.Then(f => SendAsync(f, cancellationToken), frame);
}
return(task);
}
private async void ReceiveLoop()
{
_cts = new CancellationTokenSource();
WebSocketMessage currentMessage = null;
while (!_cts.IsCancellationRequested)
{
try
{
var frame = await _webSocket.ReceiveFrameAsync(_cts.Token);
if (frame == null)
{
throw new Exception("null frame");
break;
}
OnFrameReceived(frame);
if (frame.Opcode == WebSocketOpcode.Close)
{
if (Closed != null)
{
await CloseAsync();
}
break;
}
if (frame.IsControlFrame)
{
// Handle ping frame
if (frame.Opcode == WebSocketOpcode.Ping && this.AutoSendPongResponse)
{
var pongFrame = new WebSocketClientFrame
{
Opcode = WebSocketOpcode.Pong,
Payload = frame.Payload
};
await SendAsync(pongFrame, _cts.Token);
}
}
else if (frame.IsDataFrame)
{
if (currentMessage != null)
{
throw new WebSocketException(WebSocketErrorCode.CloseInconstistentData);
}
currentMessage = new WebSocketMessage();
currentMessage.AddFrame(frame);
}
else if (frame.Opcode == WebSocketOpcode.Continuation)
{
if (currentMessage == null)
{
throw new WebSocketException(WebSocketErrorCode.CloseInconstistentData);
}
currentMessage.AddFrame(frame);
}
else
{
System.Diagnostics.Debug.WriteLine(String.Format("Other frame received: {0}", frame.Opcode));
this.LogDebug("Other frame received: {0}", frame.Opcode);
}
if (currentMessage != null && currentMessage.IsComplete)
{
OnMessageReceived(currentMessage);
currentMessage = null;
}
}
catch (WebSocketException wsex)
{
break;
}
catch (ObjectDisposedException ex)
{
//https://github.com/rdavisau/sockets-for-pcl/issues/34
break;
}
catch (TaskCanceledException ex)
{
break;
}
catch (Exception ex)
{
this.LogError("An unexpected error occurred.", ex);
this.OnError(ex);
break;
}
}
}