protected virtual async Task <TResponseMessage> SendInternal <TResponseMessage>(IRequestMessage <TResponseMessage> request, TimeSpan?timeout, string topic, CancellationToken cancellationToken)
{
if (Settings.RequestResponse == null)
{
throw new PublishMessageBusException("An attempt to send request when request/response communication was not configured for the message bus. Ensure you configure the bus properly before the application starts.");
}
// check if the cancellation was already requested
cancellationToken.ThrowIfCancellationRequested();
var requestType = request.GetType();
var publisherSettings = GetPublisherSettings(requestType);
if (topic == null)
{
topic = GetDefaultTopic(requestType, publisherSettings);
}
if (timeout == null)
{
timeout = GetDefaultRequestTimeout(requestType, publisherSettings);
}
var replyTo = Settings.RequestResponse.Topic;
var created = CurrentTime;
var expires = created.Add(timeout.Value);
// generate the request guid
var requestId = GenerateRequestId();
var requestPayload = SerializeRequest(requestType, request, requestId, replyTo, expires);
// record the request state
var requestState = new PendingRequestState(requestId, request, requestType, typeof(TResponseMessage), created, expires, cancellationToken);
PendingRequestStore.Add(requestState);
if (Log.IsTraceEnabled)
{
Log.TraceFormat("Added to PendingRequests, total is {0}", PendingRequestStore.GetCount());
}
try
{
Log.DebugFormat("Sending request message {0} to topic {1} with reply to {2} and payload size {3}", requestState, topic, replyTo, requestPayload.Length);
await PublishToTransport(requestType, request, topic, requestPayload);
}
catch (PublishMessageBusException e)
{
Log.DebugFormat("Publishing of request message failed: {0}", e);
// remove from registry
PendingRequestStore.Remove(requestId);
throw;
}
// convert Task<object> to Task<TResponseMessage>
var typedTask = Convert <TResponseMessage>(requestState.TaskCompletionSource.Task);
return(await typedTask);
}
protected virtual void CleanPendingRequests(object sender, ElapsedEventArgs args)
{
var now = CurrentTime;
var requestsToCancel = PendingRequestStore.FindAllToCancel(now);
foreach (var requestState in requestsToCancel)
{
// request is either cancelled (via CancellationToken) or expired
var canceled = requestState.CancellationToken.IsCancellationRequested
? requestState.TaskCompletionSource.TrySetCanceled(requestState.CancellationToken)
: requestState.TaskCompletionSource.TrySetCanceled();
if (PendingRequestStore.Remove(requestState.Id) && canceled)
{
Log.DebugFormat("Pending request timed-out: {0}, now: {1}", requestState, now);
// ToDo: add and API hook to these kind of situation
}
}
}
/// <summary>
/// Performs cleanup of pending requests (requests that timed out or were cancelled).
/// </summary>
public virtual void CleanPendingRequests()
{
var now = CurrentTime;
var requestsToCancel = PendingRequestStore.FindAllToCancel(now);
foreach (var requestState in requestsToCancel)
{
// request is either cancelled (via CancellationToken) or expired
var canceled = requestState.CancellationToken.IsCancellationRequested
? requestState.TaskCompletionSource.TrySetCanceled(requestState.CancellationToken)
: requestState.TaskCompletionSource.TrySetCanceled();
if (PendingRequestStore.Remove(requestState.Id) && canceled)
{
Log.DebugFormat("Pending request timed-out: {0}, now: {1}", requestState, now);
// Execute the event hook
// ToDo: sort out the ConsumerSettings arg for req/resp, for now pass null
(Settings.RequestResponse.OnMessageExpired ?? Settings.OnMessageExpired)?.Invoke(null, requestState.Request);
}
}
}
