/// <summary>
/// Reads the complete next text message from the websocket
/// </summary>
/// <returns>The text message, or null if socket was closed</returns>
private async Task <string> ReceiveNextMessageAsync(IClientWebSocketProxy ws)
{
_receiveStream.Position = 0;
WebSocketReceiveResult result;
do
{
result = await ws.ReceiveAsync(new ArraySegment <byte>(_readBuffer), _cancellationToken.Token);
if (result == null || result.Count == 0 || result.MessageType == WebSocketMessageType.Close)
{
return(null);
}
if (ws.CloseStatus.HasValue)
{
return(null);
}
Debug.Assert(result.MessageType == WebSocketMessageType.Text);
if (result.EndOfMessage && _receiveStream.Position == 0)
{
return(Encoding.UTF8.GetString(_readBuffer, 0, result.Count)); // No need to use memory stream
}
_receiveStream.Write(_readBuffer, 0, result.Count);
}while (!result.EndOfMessage);
return(Encoding.UTF8.GetString(_receiveStream.GetBuffer(), 0, (int)_receiveStream.Position));
}
/// <summary>
/// Try connecting to the specified websocket url once.
/// If the connection is successful, it will complete the function and you don't have to worry
/// about reconnects
/// </summary>
public async Task <bool> TryConnectAsync(Func <string> resolveUrl, string accessToken, Func <Task> postConnectFunc)
{
if (resolveUrl == null)
{
throw new ArgumentNullException(nameof(resolveUrl));
}
if (_disposed)
{
throw new ObjectDisposedException(nameof(JsonRpcWebSocket));
}
// Local function that will try to reconnect forever
async Task reconnect()
{
while (true)
{
// Connection lost, wait a little and try again
await Task.Delay(GetReconnectDelay(), _cancellationToken.Token);
await connect();
if (_ws != null)
{
return;
}
}
}
// Local function used for connect and re-connects
async Task connect()
{
_ws = null;
var url = resolveUrl();
try
{
var ws = CreateWebSocket(accessToken);
// Connect the websocket
_logger.LogInformation("Connecting to {0}", url);
await ws.ConnectAsync(new Uri(url), _cancellationToken.Token).OrTimeout(CONNECT_TIMEOUT);
_logger.LogInformation("Connected to {0}", url);
_ws = ws;
await EatWelcomeMessageAsync().OrTimeout(10000);
// start receiving data
_receiverTask = Task.Factory.StartNew(() => ReceiverTask(reconnect), TaskCreationOptions.LongRunning);
if (postConnectFunc != null)
{
await postConnectFunc();
}
}
catch (Exception e)
{
_ws = null;
_logger.LogWarning("Connection to '{0}' failed: {1}", url, e.Message);
}
}
// Do the first time connect
await connect();
return(_ws != null);
}
