public bool PublishSingleDelivery <T>(T message, SingleDeliverySemantic singleDeliverySemantic) where T : class
{
// TODO: make the algorithm into single delivery be injectable
Type type = typeof(T);
HashSet <IEventAggregatorTicket> tickets;
lock (_subscriptions)
{
_subscriptions.TryGetValue(type, out tickets);
}
//prevention from throwing exception
if (tickets == null)
{
return(false);
}
List <IEventAggregatorTicket> ticketsList;
lock (tickets)
{
ticketsList = new List <IEventAggregatorTicket>(tickets);
}
if (ticketsList.Count > 0)
{
ticketsList.First().Execute(message);
}
return(true);
}
public bool PublishSingleDelivery <T>(T message, SingleDeliverySemantic singleDeliverySemantic) where T : class
{
bool localDelivery = _localEventAggregator.PublishSingleDelivery(message, singleDeliverySemantic);
if (localDelivery)
{
return(true);
}
// prepare for publishing remotely
byte[] bytes;
TypeDescriptor descriptor;
try
{
PackData(message, out bytes, out descriptor);
}
catch (Exception e)
{
// we return false because the delivery is not possible at all in any semantics
logger.Warn("Could not preapre message for sending", e);
return(false);
}
bool remoteDelivery = _singleDelivery.SentSingle(RemoteDistributedEventAggregator, bytes, descriptor,
singleDeliverySemantic);
return(remoteDelivery);
}
public bool SentSingle(IEnumerable <IDistributedEventAggregator> eventAggregators, byte[] messageContent,
TypeDescriptor descriptor, SingleDeliverySemantic delivery)
{
// FIXME: this code is wrong from the performance point of view
Logger = LogManager.GetLogger(NomadConstants.NOMAD_LOGGER_REPOSITORY, typeof(BasicSingleDeliverySubsystem));
var deaWithSubscribers = new List <IDistributedEventAggregator>();
// at fist send to the other deas the is subscrbed
// NOTE: this phase can be parallelized
foreach (IDistributedEventAggregator dea in eventAggregators)
{
try
{
if (dea.IsSubscriberForType(descriptor))
{
deaWithSubscribers.Add(dea);
}
}
catch (Exception e)
{
// do nothing except for logging such exception
Logger.Warn("Exception during sending IsSubscrier", e);
}
}
if (deaWithSubscribers.Count == 0)
{
// no message can be delivered caouse no one waits for it
return(false);
}
// deliver the messages using this version
foreach (IDistributedEventAggregator dea in deaWithSubscribers)
{
try
{
bool result = dea.OnPublishSingleDelivery(messageContent, descriptor);
if (result)
{
// the message was delivered so happy day scenario (yay)
return(true);
}
}
catch (Exception e)
{
Logger.Warn("Exception during sending OnPublish phase", e);
// there was message delivery problem
if (delivery == SingleDeliverySemantic.AtLeastOnce)
{
continue;
}
else if (delivery == SingleDeliverySemantic.AtMostOnce)
{
return(true);
}
else
{
throw new InvalidOperationException("Semantic of delivery is not known", e);
}
}
}
// nothing succeeded
return(false);
}
public bool PublishSingleDelivery <T>(T message, SingleDeliverySemantic singleDeliverySemantic) where T : class
{
throw new NotImplementedException();
}
