private async Task AcceptCallback(AspNetWebSocketContext webSocketContext)
{
OwinWebSocketWrapper wrapper = null;
try
{
wrapper = new OwinWebSocketWrapper(webSocketContext);
await _webSocketFunc(wrapper.Environment);
// Making sure to close the web socket is not necessary, Asp.Net will do this for us.
wrapper.Dispose();
}
catch (Exception ex)
{
if (wrapper != null)
{
wrapper.Cancel();
wrapper.Dispose();
}
// traced as warning here because it is re-thrown
Trace.WriteWarning(Resources.Trace_WebSocketException, ex);
throw;
}
}
private async Task WebSocketUpgrade(string subProtocol, int receiveBufferSize, TimeSpan keepAliveInterval, ArraySegment <byte>?internalBuffer)
{
var context = await _context.AcceptWebSocketAsync(subProtocol, receiveBufferSize, keepAliveInterval);
var wrapper = new OwinWebSocketWrapper(context, _environment.Get <CancellationToken>(Constants.CallCancelledKey));
await _webSocketFunc(wrapper.Environment);
await wrapper.CleanupAsync();
}
private async Task HandleSocket(OwinWebSocketWrapper webSocket, ArraySegment <byte> receivedDataBuffer,
CancellationToken cancellationToken, MemoryStream memoryStream)
{
//Checks WebSocket state.
while (webSocket.State == WebSocketState.Open)
{
await ReadMessage(webSocket, receivedDataBuffer, memoryStream);
memoryStream.Position = 0;
//Sends data back.
await webSocket.SendAsync(new ArraySegment <byte>(memoryStream.ToArray()),
WebSocketMessageType.Text, true, cancellationToken);
memoryStream.Position = 0;
memoryStream.SetLength(0);
}
}
//Asynchronous request handler.
public async Task OnAccept(IDictionary <string, object> websocketContext, IOwinContext context)
{
//Gets the current WebSocket object.
OwinWebSocketWrapper webSocket = new OwinWebSocketWrapper(websocketContext);
/*We define a certain constant which will represent
* size of received data. It is established by us and
* we can set any value. We know that in this case the size of the sent
* data is very small.
*/
const int maxMessageSize = 1024;
//Buffer for received bits.
var receivedDataBuffer = new ArraySegment <Byte>(new Byte[maxMessageSize]);
MemoryStream memoryStream = new MemoryStream();
var cancellationToken = CancellationToken.None;
await Task.Run(() => HandleSocket(webSocket, receivedDataBuffer, cancellationToken, memoryStream));
}
