private Task<bool> IterateAndConnect(IEnumerator<Host> hostsEnumerator, Dictionary<IPEndPoint, Exception> triedHosts)
{
var available = hostsEnumerator.MoveNext();
if (!available)
{
return TaskHelper.FromException<bool>(new NoHostAvailableException(triedHosts));
}
var host = hostsEnumerator.Current;
var c = new Connection(_serializer, host.Address, _config);
return ((Task) c
.Open())
.ContinueWith(t =>
{
if (t.Status == TaskStatus.RanToCompletion)
{
_connection = c;
_host = host;
_logger.Info("Connection established to {0}", c.Address);
return TaskHelper.ToTask(true);
}
if (t.IsFaulted && t.Exception != null)
{
var ex = t.Exception.InnerException;
if (ex is UnsupportedProtocolVersionException)
{
//Use the protocol version used to parse the response message
var nextVersion = _serializer.ProtocolVersion;
_logger.Info(string.Format("{0}, trying with version {1}", ex.Message, nextVersion));
c.Dispose();
if (ProtocolVersion < 1)
{
throw new DriverInternalError("Invalid protocol version");
}
//Retry using the new protocol version
return Connect(true);
}
//There was a socket exception or an authentication exception
triedHosts.Add(host.Address, ex);
c.Dispose();
return IterateAndConnect(hostsEnumerator, triedHosts);
}
throw new TaskCanceledException("The ControlConnection could not be connected.");
}, TaskContinuationOptions.ExecuteSynchronously)
.Unwrap();
}
/// <exception cref="System.Net.Sockets.SocketException">Throws a SocketException when the connection could not be established with the host</exception>
/// <exception cref="AuthenticationException" />
/// <exception cref="UnsupportedProtocolVersionException"></exception>
internal virtual Task<Connection> CreateConnection()
{
Logger.Info("Creating a new connection to the host " + _host.Address);
var c = new Connection(_serializer, _host.Address, _config);
return c.Open().ContinueWith(t =>
{
if (t.Status == TaskStatus.RanToCompletion)
{
if (_config.GetPoolingOptions(_serializer.ProtocolVersion).GetHeartBeatInterval() > 0)
{
//Heartbeat is enabled, subscribe for possible exceptions
c.OnIdleRequestException += OnIdleRequestException;
}
return c;
}
Logger.Info("The connection to {0} could not be opened", _host.Address);
c.Dispose();
if (t.Exception != null)
{
t.Exception.Handle(_ => true);
Logger.Error(t.Exception.InnerException);
throw t.Exception.InnerException;
}
throw new TaskCanceledException("The connection creation task was cancelled");
}, TaskContinuationOptions.ExecuteSynchronously);
}
