public async Task Ping(CancellationToken token)
{
var payload = Guid.NewGuid().ToByteArray();
var pongSource = new TaskCompletionSource <object>();
token.Register(() => pongSource.TrySetCanceled());
EventHandler <ControlFrameEventArgs> completionTrigger = (sender, e) => {
if ((e.ControlFrame.FrameType == ControlFrame.Type.Pong) &&
payload.SequenceEqual(e.ControlFrame.Payload))
{
pongSource.TrySetResult(null);
}
};
OnControlFrame += completionTrigger;
await WebSocketProtocol.SendControlFrame(OutputStream, new ControlFrame {
Payload = payload,
FrameType = ControlFrame.Type.Ping,
});
// either wait until they read it for us
// or aquire the readlock and read it on our own
var readLockAcquire = InputStream.ManualAcquire();
var pongTask = pongSource.Task;
if (pongTask == await Task.WhenAny(readLockAcquire.Task, pongTask))
{
System.Diagnostics.Debug.WriteLine("nice, they read it for us");
readLockAcquire.Cancel();
}
else
{
System.Diagnostics.Debug.WriteLine("welp, our work");
using (var readLock = await readLockAcquire.Task)
await WebSocketProtocol.ReadFrameGroupLockAcquired(readLock, HandleControlFrame, token, false);
// pls tell me that this was the frame we needed
if (!pongTask.IsCompleted)
{
throw new InvalidDataException("we pinged and they sent something else. welp.");
}
}
OnControlFrame -= completionTrigger;
}
private async Task HandleControlFrame(ControlFrame frame)
{
var eventargs = new ControlFrameEventArgs(frame);
var controlFrameEvent = OnControlFrame;
if (controlFrameEvent != null)
{
await Task.Factory.FromAsync(controlFrameEvent.BeginInvoke,
controlFrameEvent.EndInvoke, this, eventargs, null);
}
if (!eventargs.SuppressAutoResponse && AutoPong && (frame.FrameType == ControlFrame.Type.Ping))
{
await WebSocketProtocol.SendControlFrame(OutputStream,
new ControlFrame { FrameType = ControlFrame.Type.Pong, Payload = frame.Payload });
}
}
private async Task <bool> CheckEndOfFrame(CancellationToken token)
{
System.Diagnostics.Debug.WriteLineIf(FrameOffset >= FrameHeader.PayloadLength, FrameHeader.GroupIsComplete, "WSIS: end of frame, is group complete?");
if (FrameOffset >= FrameHeader.PayloadLength)
{
// end of frame
if (FrameHeader.GroupIsComplete)
{
return(true);
}
else
{
// read another header and continue with the next group:
BeginReadingFrame(await WebSocketProtocol.ReadFrameHeader(Underlying, token));
}
}
return(false);
}
public Task SendStream(Stream stream)
{
return(WebSocketProtocol.SendStream(OutputStream, stream, Masking));
}
public Task SendBinaryMessage(byte[] data, int offset, int length)
{
return(WebSocketProtocol.SendByteArrayFrame(OutputStream, data, offset, length, Masking));
}
public Task SendTextMessage(string message)
{
return(WebSocketProtocol.SendTextFrame(OutputStream, message, Masking));
}
void IDisposable.Dispose()
{
WebSocketProtocol.SendControlFrame(OutputStream, new ControlFrame {
FrameType = ControlFrame.Type.Close,
}).Wait();
}
public Task <object> ReceiveAnyMessage(CancellationToken token = default(CancellationToken))
{
return(WebSocketProtocol.ReadFrameGroup(InputStream, HandleControlFrame, token));
}