/// <summary>
/// Unregisters an observer. This methods is invoked by an observer.
/// </summary>
/// <param name="topic">The topic.</param>
/// <param name="entityId">The entity id of the observable.</param>
/// This method is called by a management service or actor.
/// <returns>The asynchronous result of the operation.</returns>
public async Task UnregisterObserverActorAsync(string topic, EntityId entityId)
{
EntityId id = await this.GetEntityIdAsync();
if (id == null)
{
return;
}
if (string.IsNullOrWhiteSpace(topic))
{
throw new ArgumentException($"The {nameof(topic)} parameter cannot be null.", nameof(topic));
}
if (entityId == null)
{
throw new ArgumentException($"The {nameof(entityId)} parameter cannot be null.", nameof(entityId));
}
for (int k = 1; k <= ConfigurationHelper.MaxQueryRetryCount; k++)
{
try
{
ConditionalValue <Dictionary <Uri, EntityId> > topicState = await this.StateManager.TryGetStateAsync <Dictionary <Uri, EntityId> >(topic);
if (!topicState.HasValue)
{
ActorEventSource.Current.Message(
$"Observer not registered to the specified topic.\r\n[Observable]: {entityId}\r\n[Observer]: {id}\r\n[Publication]: Topic=[{topic}]");
return;
}
Dictionary <Uri, EntityId> observableDictionary = topicState.Value;
if (!observableDictionary.ContainsKey(entityId.EntityUri))
{
ActorEventSource.Current.Message(
$"Observer not registered to the specified observable.\r\n[Observable]: {entityId}\r\n[Observer]: {id}\r\n[Publication]: Topic=[{topic}]");
return;
}
if (entityId.Kind == EntityKind.Actor)
{
IServerObservableActor actorProxy = ActorProxy.Create <IServerObservableActor>(entityId.ActorId, entityId.ServiceUri);
await actorProxy.UnregisterObserverAsync(topic, id);
}
else
{
IServerObservableService serviceProxy = entityId.PartitionKey.HasValue
? ServiceProxy.Create <IServerObservableService>(entityId.ServiceUri, new ServicePartitionKey(entityId.PartitionKey.Value))
: ServiceProxy.Create <IServerObservableService>(entityId.ServiceUri);
await serviceProxy.UnregisterObserverAsync(topic, id);
}
observableDictionary.Remove(entityId.EntityUri);
if (!observableDictionary.Any())
{
await this.StateManager.TryRemoveStateAsync(topic);
}
else
{
await this.StateManager.SetStateAsync(topic, observableDictionary);
}
ActorEventSource.Current.Message(
$"Observer successfully unregistered.\r\n[Observable]: {entityId}\r\n[Observer]: {id}\r\n[Subscription]: Topic=[{topic}]");
return;
}
catch (FabricTransientException ex)
{
ActorEventSource.Current.Error(ex);
}
catch (AggregateException ex)
{
foreach (Exception e in ex.InnerExceptions)
{
ActorEventSource.Current.Error(e);
}
throw;
}
catch (Exception ex)
{
ActorEventSource.Current.Error(ex);
throw;
}
await Task.Delay(ConfigurationHelper.BackoffQueryDelay);
}
throw new TimeoutException(Constants.RetryTimeoutExhausted);
}