public StreamConsumerData AddConsumer(GuidId subscriptionId, StreamId streamId, IStreamConsumerExtension streamConsumer, IStreamFilterPredicateWrapper filter)
{
var consumerData = new StreamConsumerData(subscriptionId, streamId, streamConsumer, filter);
queueData.Add(subscriptionId, consumerData);
lastActivityTime = DateTime.UtcNow;
return consumerData;
}
public async Task<StreamHandshakeToken> DeliverBatch(GuidId subscriptionId, Immutable<IBatchContainer> batch, StreamHandshakeToken handshakeToken)
{
foreach (var each in batch.Value.GetEvents<object>())
await handler(each.Item1);
return null;
}
public StreamConsumerData(GuidId subscriptionId, StreamId streamId, IStreamConsumerExtension streamConsumer, IStreamFilterPredicateWrapper filter)
{
SubscriptionId = subscriptionId;
StreamId = streamId;
StreamConsumer = streamConsumer;
Filter = filter;
}
public bool RemoveConsumer(GuidId subscriptionId, Logger logger)
{
StreamConsumerData consumer;
if (!queueData.TryGetValue(subscriptionId, out consumer)) return false;
consumer.SafeDisposeCursor(logger);
return queueData.Remove(subscriptionId);
}
public Task RegisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider, IStreamConsumerExtension streamConsumer, IStreamFilterPredicateWrapper filter)
{
if (!IsImplicitSubscriber(streamConsumer, streamId))
{
throw new ArgumentOutOfRangeException(streamId.ToString(), "Only implicit subscriptions are supported.");
}
return TaskDone.Done;
}
public bool RemoveConsumer(GuidId subscriptionId)
{
StreamConsumerData consumer;
if (!queueData.TryGetValue(subscriptionId, out consumer)) return false;
if (consumer.Cursor != null)
{
// kill cursor activity and ensure it does not start again on this consumer data.
consumer.Cursor.Dispose();
consumer.Cursor = null;
}
return queueData.Remove(subscriptionId);
}
public Task OnSubscriptionFailure(GuidId subscriptionId, string streamProviderName, IStreamIdentity streamIdentity,
StreamSequenceToken sequenceToken)
{
return TaskDone.Done;
}
Task IStreamPubSub.RegisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider, IStreamConsumerExtension streamConsumer, IStreamFilterPredicateWrapper filter)
{
return registry.RegisterConsumer(subscriptionId, streamId, streamProvider, streamConsumer, filter);
}
private async Task <StreamSubscriptionHandle <T> > SubscribeAsyncImpl(
IAsyncObserver <T> observer,
IAsyncBatchObserver <T> batchObserver,
StreamSequenceToken token,
StreamFilterPredicate filterFunc = null,
object filterData = null)
{
if (token != null && !IsRewindable)
{
throw new ArgumentNullException("token", "Passing a non-null token to a non-rewindable IAsyncObservable.");
}
if (observer is GrainReference)
{
throw new ArgumentException("On-behalf subscription via grain references is not supported. Only passing of object references is allowed.", nameof(observer));
}
if (batchObserver is GrainReference)
{
throw new ArgumentException("On-behalf subscription via grain references is not supported. Only passing of object references is allowed.", nameof(batchObserver));
}
if (logger.IsEnabled(LogLevel.Debug))
{
logger.Debug("Subscribe Token={Token}", token);
}
await BindExtensionLazy();
IStreamFilterPredicateWrapper filterWrapper = null;
if (filterFunc != null)
{
filterWrapper = new FilterPredicateWrapperData(filterData, filterFunc);
}
if (logger.IsEnabled(LogLevel.Debug))
{
logger.Debug("Subscribe - Connecting to Rendezvous {0} My GrainRef={1} Token={2}",
pubSub, myGrainReference, token);
}
GuidId subscriptionId = pubSub.CreateSubscriptionId(stream.StreamId, myGrainReference);
// Optimistic Concurrency:
// In general, we should first register the subsription with the pubsub (pubSub.RegisterConsumer)
// and only if it succeeds store it locally (myExtension.SetObserver).
// Basicaly, those 2 operations should be done as one atomic transaction - either both or none and isolated from concurrent reads.
// BUT: there is a distributed race here: the first msg may arrive before the call is awaited
// (since the pubsub notifies the producer that may immideately produce)
// and will thus not find the subriptionHandle in the extension, basically violating "isolation".
// Therefore, we employ Optimistic Concurrency Control here to guarantee isolation:
// we optimisticaly store subscriptionId in the handle first before calling pubSub.RegisterConsumer
// and undo it in the case of failure.
// There is no problem with that we call myExtension.SetObserver too early before the handle is registered in pub sub,
// since this subscriptionId is unique (random Guid) and no one knows it anyway, unless successfully subscribed in the pubsub.
var subriptionHandle = myExtension.SetObserver(subscriptionId, stream, observer, batchObserver, token, filterWrapper);
try
{
await pubSub.RegisterConsumer(subscriptionId, stream.StreamId, streamProviderName, myGrainReference, filterWrapper);
return(subriptionHandle);
}
catch (Exception)
{
// Undo the previous call myExtension.SetObserver.
myExtension.RemoveObserver(subscriptionId);
throw;
}
}
public void RemoveSubscriber_Impl(GuidId subscriptionId, StreamId streamId)
{
if (IsShutdown) return;
StreamConsumerCollection streamData;
if (!pubSubCache.TryGetValue(streamId, out streamData)) return;
// remove consumer
bool removed = streamData.RemoveConsumer(subscriptionId, logger);
if (removed && logger.IsVerbose) logger.Verbose((int)ErrorCode.PersistentStreamPullingAgent_10, "Removed Consumer: subscription={0}, for stream {1}.", subscriptionId, streamId);
if (streamData.Count == 0)
pubSubCache.Remove(streamId);
}
public bool TryGetConsumer(GuidId subscriptionId, out StreamConsumerData data)
{
return queueData.TryGetValue(subscriptionId, out data);
}
public async Task<bool> FaultSubscription(StreamId streamId, GuidId subscriptionId)
{
var streamRendezvous = GetRendezvousGrain(streamId);
await streamRendezvous.FaultSubscription(subscriptionId);
return true;
}
public Task UnregisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider)
{
var streamRendezvous = GetRendezvousGrain(streamId);
return(streamRendezvous.UnregisterConsumer(subscriptionId, streamId));
}
public Task RegisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider, IStreamConsumerExtension streamConsumer, StreamSequenceToken token, IStreamFilterPredicateWrapper filter)
{
var streamRendezvous = GetRendezvousGrain(streamId);
return(streamRendezvous.RegisterConsumer(subscriptionId, streamId, streamConsumer, token, filter));
}
public Task <bool> FaultSubscription(GuidId subscriptionId, StreamId streamId)
{
return(IsImplicitSubscriber(subscriptionId, streamId)
? Task.FromResult(false)
: explicitPubSub.FaultSubscription(subscriptionId, streamId));
}
private bool IsImplicitSubscriber(GuidId subscriptionId, StreamId streamId)
{
return(SubscriptionMarker.IsImplicitSubscription(subscriptionId.Guid));
}
public async Task <List <GuidId> > GetAllSubscriptions(StreamId streamId, IStreamConsumerExtension streamConsumer)
{
return(IsImplicitSubscriber(streamConsumer, streamId)
? new List <GuidId>(new [] { GuidId.GetGuidId(streamConsumer.GetPrimaryKey()) })
: await explicitPubSub.GetAllSubscriptions(streamId, streamConsumer));
}
public Task UnregisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider)
{
return(IsImplicitSubscriber(subscriptionId, streamId)
? TaskDone.Done
: explicitPubSub.UnregisterConsumer(subscriptionId, streamId, streamProvider));
}
public Task RegisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider, IStreamConsumerExtension streamConsumer, StreamSequenceToken token, IStreamFilterPredicateWrapper filter)
{
return(IsImplicitSubscriber(streamConsumer, streamId)
? TaskDone.Done
: explicitPubSub.RegisterConsumer(subscriptionId, streamId, streamProvider, streamConsumer, token, filter));
}
public Task RegisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider, IStreamConsumerExtension streamConsumer, IStreamFilterPredicateWrapper filter)
{
return implicitPubSub.IsImplicitSubscriber(streamConsumer, streamId)
? implicitPubSub.RegisterConsumer(subscriptionId, streamId, streamProvider, streamConsumer, filter)
: explicitPubSub.RegisterConsumer(subscriptionId, streamId, streamProvider, streamConsumer, filter);
}
public Task RegisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider, IStreamConsumerExtension streamConsumer, IStreamFilterPredicateWrapper filter)
{
var streamRendezvous = GetRendezvousGrain(streamId);
return streamRendezvous.RegisterConsumer(subscriptionId, streamId, streamConsumer, filter);
}
public GuidId CreateSubscriptionId(IAddressable requesterAddress, StreamId streamId)
{
return(GuidId.GetNewGuidId());
}
public StreamSubscriptionHandlerFactory(IStreamProviderManager manager, IStreamIdentity streamId, string providerName, GuidId subscriptionId)
{
this.manager = manager;
this.StreamId = streamId;
this.ProviderName = providerName;
this.SubscriptionId = subscriptionId;
}
public async Task RemoveSubscription(string streamProviderName, IStreamIdentity streamId, Guid subscriptionId)
{
await streamPubSub.UnregisterConsumer(GuidId.GetGuidId(subscriptionId), StreamId.GetStreamId(streamId.Guid, streamProviderName, streamId.Namespace), streamProviderName);
}
// Called by rendezvous when new remote subscriber subscribes to this stream.
private async Task AddSubscriber_Impl(
GuidId subscriptionId,
StreamId streamId,
IStreamConsumerExtension streamConsumer,
StreamSequenceToken cacheToken,
IStreamFilterPredicateWrapper filter)
{
if (IsShutdown) return;
StreamConsumerCollection streamDataCollection;
if (!pubSubCache.TryGetValue(streamId, out streamDataCollection))
{
streamDataCollection = new StreamConsumerCollection(DateTime.UtcNow);
pubSubCache.Add(streamId, streamDataCollection);
}
StreamConsumerData data;
if (!streamDataCollection.TryGetConsumer(subscriptionId, out data))
data = streamDataCollection.AddConsumer(subscriptionId, streamId, streamConsumer, filter ?? DefaultStreamFilter);
if (await DoHandshakeWithConsumer(data, cacheToken))
{
if (data.State == StreamConsumerDataState.Inactive)
RunConsumerCursor(data, data.Filter).Ignore(); // Start delivering events if not actively doing so
}
}
public async Task RegisterConsumer(
GuidId subscriptionId,
StreamId streamId,
IStreamConsumerExtension streamConsumer,
IStreamFilterPredicateWrapper filter)
{
PubSubSubscriptionState pubSubState = State.Consumers.FirstOrDefault(s => s.Equals(subscriptionId));
if (pubSubState == null)
{
pubSubState = new PubSubSubscriptionState(subscriptionId, streamId, streamConsumer);
State.Consumers.Add(pubSubState);
}
if (pubSubState.IsFaulted)
{
throw new FaultedSubscriptionException(subscriptionId, streamId);
}
if (filter != null)
{
pubSubState.AddFilter(filter);
}
counterConsumersAdded.Increment();
counterConsumersTotal.Increment();
LogPubSubCounts("RegisterConsumer {0}", streamConsumer);
await WriteStateAsync();
int numProducers = State.Producers.Count;
if (numProducers > 0)
{
if (logger.IsVerbose)
{
logger.Info("Notifying {0} existing producer(s) about new consumer {1}. Producers={2}",
numProducers, streamConsumer, Utils.EnumerableToString(State.Producers));
}
// Notify producers about a new streamConsumer.
var tasks = new List <Task>();
var producers = State.Producers.ToList();
bool someProducersRemoved = false;
foreach (var producerState in producers)
{
PubSubPublisherState producer = producerState; // Capture loop variable
if (!IsActiveProducer(producer.Producer))
{
// Producer is not active (could be stopping / shutting down) so skip
if (logger.IsVerbose)
{
logger.Verbose("Producer {0} on stream {1} is not active - skipping.", producer, streamId);
}
continue;
}
Task addSubscriberPromise = producer.Producer.AddSubscriber(subscriptionId, streamId, streamConsumer, filter)
.ContinueWith(t =>
{
if (t.IsFaulted)
{
var exc = t.Exception.GetBaseException();
if (exc is GrainExtensionNotInstalledException)
{
logger.Warn((int)ErrorCode.Stream_ProducerIsDead,
"Producer {0} on stream {1} is no longer active - discarding.",
producer, streamId);
// This publisher has gone away, so we should cleanup pub-sub state.
bool removed = State.Producers.Remove(producer);
someProducersRemoved = true; // Re-save state changes at end
counterProducersRemoved.Increment();
counterProducersTotal.DecrementBy(removed ? 1 : 0);
// And ignore this error
}
else
{
throw exc;
}
}
}, TaskContinuationOptions.ExecuteSynchronously);
tasks.Add(addSubscriberPromise);
}
Exception exception = null;
try
{
await Task.WhenAll(tasks);
}
catch (Exception exc)
{
exception = exc;
}
if (someProducersRemoved)
{
await WriteStateAsync();
}
if (exception != null)
{
throw exception;
}
}
}
internal bool IsImplicitSubscriber(GuidId subscriptionId, StreamId streamId)
{
return SubscriptionMarker.IsImplicitSubscription(subscriptionId.Guid);
}
public Task AddSubscriber(GuidId subscriptionId, InternalStreamId streamId, IStreamConsumerExtension streamConsumer, string filterData)
{
return(Task.CompletedTask);
}
internal void RemoveRemoteSubscriber(GuidId subscriptionId)
{
Tuple<IStreamConsumerExtension, IStreamFilterPredicateWrapper> ignore;
consumers.TryRemove(subscriptionId, out ignore);
if (consumers.Count == 0)
{
// Unsubscribe from PubSub?
}
}
public Task RemoveSubscriber(GuidId subscriptionId, InternalStreamId streamId)
{
return(Task.CompletedTask);
}
internal void AddRemoteSubscriber(GuidId subscriptionId, IStreamConsumerExtension streamConsumer, string filterData)
{
consumers.TryAdd(subscriptionId, (streamConsumer, filterData));
}
public Task <bool> FaultSubscription(StreamId streamId, GuidId subscriptionId)
{
return(Task.FromResult(false));
}
internal void AddRemoteSubscriber(GuidId subscriptionId, IStreamConsumerExtension streamConsumer, IStreamFilterPredicateWrapper filter)
{
consumers.TryAdd(subscriptionId, Tuple.Create(streamConsumer, filter));
}
public StreamSubscriptionHandleImpl(GuidId subscriptionId, StreamImpl <T> streamImpl)
: this(subscriptionId, null, null, streamImpl, null, null)
{
}
Task<bool> IStreamPubSub.FaultSubscription(StreamId streamId, GuidId subscriptionId)
{
return registry.FaultSubscription(streamId, subscriptionId);
}
public Task RemoveSubscriber(GuidId subscriptionId, StreamId streamId)
{
RemoveSubscriber_Impl(subscriptionId, streamId);
return(TaskDone.Done);
}
Task IStreamPubSub.UnregisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider)
{
return registry.UnregisterConsumer(subscriptionId, streamId, streamProvider);
}
public async Task <StreamSequenceToken> DeliverItem(GuidId subscriptionId, Immutable <object> item, StreamSequenceToken currentToken, StreamSequenceToken prevToken)
{
await handler(item);
return(null);
}
public Task<bool> FaultSubscription(StreamId streamId, GuidId subscriptionId)
{
return implicitPubSub.IsImplicitSubscriber(subscriptionId, streamId)
? implicitPubSub.FaultSubscription(streamId, subscriptionId)
: explicitPubSub.FaultSubscription(streamId, subscriptionId);
}
public Task <StreamSequenceToken> GetSequenceToken(GuidId subscriptionId) => Task.FromResult((StreamSequenceToken)null);
public Task UnregisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider)
{
return implicitPubSub.IsImplicitSubscriber(subscriptionId, streamId)
? implicitPubSub.UnregisterConsumer(subscriptionId, streamId, streamProvider)
: explicitPubSub.UnregisterConsumer(subscriptionId, streamId, streamProvider);
}
public Task CompleteStream(GuidId subscriptionId) => TaskDone.Done;
public Task UnregisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider)
{
var streamRendezvous = GetRendezvousGrain(streamId);
return streamRendezvous.UnregisterConsumer(subscriptionId, streamId);
}
public Task ErrorInStream(GuidId subscriptionId, Exception exc) => TaskDone.Done;
public StreamConsumerData AddConsumer(GuidId subscriptionId, StreamId streamId, IStreamConsumerExtension streamConsumer, StreamSequenceToken token, IStreamFilterPredicateWrapper filter)
{
var consumerData = new StreamConsumerData(subscriptionId, streamId, streamConsumer, filter);
queueData.Add(subscriptionId, consumerData);
return consumerData;
}
public Task RemoveSubscriber(GuidId subscriptionId, StreamId streamId)
{
RemoveSubscriber_Impl(subscriptionId, streamId);
return(Task.CompletedTask);
}
public bool Contains(GuidId subscriptionId)
{
return queueData.ContainsKey(subscriptionId);
}
public bool Contains(GuidId subscriptionId)
{
return(queueData.ContainsKey(subscriptionId));
}
public Task AddSubscriber(
GuidId subscriptionId,
StreamId streamId,
IStreamConsumerExtension streamConsumer,
IStreamFilterPredicateWrapper filter)
{
if (logger.IsVerbose) logger.Verbose((int)ErrorCode.PersistentStreamPullingAgent_09, "AddSubscriber: Stream={0} Subscriber={1}.", streamId, streamConsumer);
// cannot await here because explicit consumers trigger this call, so it could cause a deadlock.
AddSubscriber_Impl(subscriptionId, streamId, streamConsumer, null, filter)
.LogException(logger, ErrorCode.PersistentStreamPullingAgent_26,
String.Format("Failed to add subscription for stream {0}." , streamId))
.Ignore();
return TaskDone.Done;
}
public bool TryGetConsumer(GuidId subscriptionId, out StreamConsumerData data)
{
return(queueData.TryGetValue(subscriptionId, out data));
}
public Task RemoveSubscriber(GuidId subscriptionId, StreamId streamId)
{
RemoveSubscriber_Impl(subscriptionId, streamId);
return TaskDone.Done;
}
public Task OnSubscriptionFailure(GuidId subscriptionId, string streamProviderName, IStreamIdentity streamIdentity,
StreamSequenceToken sequenceToken)
{
return(TaskDone.Done);
}
internal FaultedSubscriptionException(GuidId subscriptionId, StreamId streamId)
: base(string.Format(ErrorStringFormat, subscriptionId.Guid, streamId)) { }
internal void AddRemoteSubscriber(GuidId subscriptionId, IStreamConsumerExtension streamConsumer, IStreamFilterPredicateWrapper filter)
{
consumers.TryAdd(subscriptionId, Tuple.Create(streamConsumer, filter));
}
public Task<bool> FaultSubscription(StreamId streamId, GuidId subscriptionId)
{
return Task.FromResult(false);
}
private async Task DeliverToRemote(IStreamConsumerExtension remoteConsumer, StreamId streamId, GuidId subscriptionId, object item, bool optimizeForImmutableData, bool fireAndForgetDelivery)
{
try
{
if (optimizeForImmutableData)
{
await remoteConsumer.DeliverImmutable(subscriptionId, streamId, new Immutable <object>(item), null, null);
}
else
{
await remoteConsumer.DeliverMutable(subscriptionId, streamId, item, null, null);
}
}
catch (ClientNotAvailableException)
{
Tuple <IStreamConsumerExtension, IStreamFilterPredicateWrapper> discard;
if (consumers.TryRemove(subscriptionId, out discard))
{
streamPubSub.UnregisterConsumer(subscriptionId, streamId, streamId.ProviderName).Ignore();
logger.Warn(ErrorCode.Stream_ConsumerIsDead,
"Consumer {0} on stream {1} is no longer active - permanently removing Consumer.", remoteConsumer, streamId);
}
}
catch (Exception ex)
{
if (!fireAndForgetDelivery)
{
throw;
}
this.logger.LogWarning(ex, "Failed to deliver message to consumer on {SubscriptionId} for stream {StreamId}.", subscriptionId, streamId);
}
}
public Task UnregisterConsumer(GuidId subscriptionId, StreamId streamId, string streamProvider)
{
return TaskDone.Done;
}
private async Task NotifyComplete(IStreamConsumerExtension remoteConsumer, GuidId subscriptionId, StreamId streamId, bool fireAndForgetDelivery)
{
try
{
await remoteConsumer.CompleteStream(subscriptionId);
} catch (Exception ex)
{
if (!fireAndForgetDelivery)
{
throw;
}
this.logger.LogWarning(ex, "Failed to notify consumer of stream completion on {SubscriptionId} for stream {StreamId}.", subscriptionId, streamId);
}
}
internal LocalObjectData(IAddressable obj, GuidId observerId, IGrainMethodInvoker invoker)
{
LocalObject = new WeakReference(obj);
ObserverId = observerId;
Invoker = invoker;
Messages = new Queue<Message>();
Running = false;
}
internal void AddRemoteSubscriber(GuidId subscriptionId, IStreamConsumerExtension streamConsumer)
{
consumers.TryAdd(subscriptionId, streamConsumer);
}