Package org.apache.pekko.actor.typed.delivery.internal

Class ProducerControllerImpl$

java.lang.Object

org.apache.pekko.actor.typed.delivery.internal.ProducerControllerImpl$

public class ProducerControllerImpl$
extends Object

INTERNAL API

==== Design notes ====

The producer will start the flow by sending a ProducerController.Start message to the ProducerController with message adapter reference to convert ProducerController.RequestNext message. The ProducerController sends RequestNext to the producer, which is then allowed to send one message to the ProducerController.

The producer and ProducerController are supposed to be local so that these messages are fast and not lost.

The ProducerController sends the first message to the ConsumerController without waiting for a Request from the ConsumerController. The main reason for this is that when used with Cluster Sharding the first message will typically create the ConsumerController. It's also a way to connect the ProducerController and ConsumerController in a dynamic way, for example when the ProducerController is replaced.

When the first message is received by the ConsumerController it sends back the initial Request, with demand of how many messages it can accept.

Apart from the first message the ProducerController will not send more messages than requested by the ConsumerController.

When there is demand from the consumer side the ProducerController sends RequestNext to the actual producer, which is then allowed to send one more message.

Each message is wrapped by the ProducerController in ConsumerController.SequencedMessage with a monotonically increasing sequence number without gaps, starting at 1.

In other words, the "request" protocol to the application producer and consumer is one-by-one, but between the ProducerController and ConsumerController it's window of messages in flight.

The Request message also contains a confirmedSeqNr that is the acknowledgement from the consumer that it has received and processed all messages up to that sequence number.

The ConsumerController will send ProducerControllerImpl.Resend if a lost message is detected and then the ProducerController will resend all messages from that sequence number. The producer keeps unconfirmed messages in a buffer to be able to resend them. The buffer size is limited by the request window size.

The resending is optional, and the ConsumerController can be started with resendLost=false to ignore lost messages, and then the ProducerController will not buffer unconfirmed messages. In that mode it provides only flow control but no reliable delivery.

Field Summary

Fields

Modifier and Type	Field	Description
static final ProducerControllerImpl$	MODULE$	Static reference to the singleton instance of this Scala object.

Constructor Summary

Constructors

Constructor	Description
ProducerControllerImpl$()

Method Summary

Modifier and Type	Method	Description
<A> Behavior<ProducerController.Command<A>>	apply(String producerId, scala.Option<Behavior<DurableProducerQueue.Command<A>>> durableQueueBehavior, ProducerController.Settings settings, scala.Function1<ConsumerController.SequencedMessage<A>,scala.runtime.BoxedUnit> send, scala.reflect.ClassTag<A> evidence$2)	For custom send function.
<A> Behavior<ProducerController.Command<A>>	apply(String producerId, scala.Option<Behavior<DurableProducerQueue.Command<A>>> durableQueueBehavior, ProducerController.Settings settings, scala.reflect.ClassTag<A> evidence$1)
<A> scala.collection.immutable.Seq<org.apache.pekko.actor.typed.delivery.internal.ChunkedMessage>	createChunks(A m, int chunkSize, Serialization serialization)
void	enforceLocalProducer(ActorRef<?> ref)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

MODULE$

public static final ProducerControllerImpl$ MODULE$

Static reference to the singleton instance of this Scala object.

Constructor Details

ProducerControllerImpl$

public ProducerControllerImpl$()

Method Details

apply

public <A> Behavior<ProducerController.Command<A>> apply(String producerId,
 scala.Option<Behavior<DurableProducerQueue.Command<A>>> durableQueueBehavior,
 ProducerController.Settings settings,
 scala.reflect.ClassTag<A> evidence$1)

apply

public <A> Behavior<ProducerController.Command<A>> apply(String producerId,
 scala.Option<Behavior<DurableProducerQueue.Command<A>>> durableQueueBehavior,
 ProducerController.Settings settings,
 scala.Function1<ConsumerController.SequencedMessage<A>,scala.runtime.BoxedUnit> send,
 scala.reflect.ClassTag<A> evidence$2)

For custom send function. For example used with Sharding where the message must be wrapped in ShardingEnvelope(SequencedMessage(msg)).

enforceLocalProducer

public void enforceLocalProducer(ActorRef<?> ref)

createChunks

public <A>
scala.collection.immutable.Seq<org.apache.pekko.actor.typed.delivery.internal.ChunkedMessage> createChunks(A m,
 int chunkSize,
 Serialization serialization)