/// <summary>
/// Subscribes the specified observer.
/// </summary>
/// <param name="observer">The observer.</param>
/// <returns>An IDisposable.</returns>
public IDisposable Subscribe(IObserver <T> observer)
{
if (_theObserver != null)
{
throw new InvalidOperationException(
"There should be only one observer attached to the Firehose Observable");
}
var messageTransportWaitCallBackId = Guid.Empty;
try
{
_theObserver = observer;
var topicObserver = new TopicObserver(_topic, observer);
topicObserver.Start();
return
(Disposable.Create(
() => topicObserver.Stop()));
}
catch (Exception ex)
{
Tracer.TraceSource.TraceEvent(
TraceEventType.Error,
0,
"Fire hose observable - topic:{0}, waitCallbackId:{1}, unable to subscribe to fire hose observable - {2}",
_topic,
messageTransportWaitCallBackId,
ex);
throw;
}
}
public override void SetContext(IOperatorContext context)
{
if (!context.TryGetElement <MessageRouter>(MessageRouter.ContextHandle, out var messageRouter))
{
throw new InvalidOperationException("Could not retrieve the message router from the operator context.");
}
_topicObserver = new TopicObserver(Params._topic, messageRouter, this);
_scheduler = context.Scheduler;
base.SetContext(context);
}
