Package akka.stream.scaladsl

Class BroadcastHub<T>

java.lang.Object

akka.stream.stage.GraphStageWithMaterializedValue<SinkShape<T>,Source<T,NotUsed>>

akka.stream.scaladsl.BroadcastHub<T>

All Implemented Interfaces:

Graph<SinkShape<T>,Source<T,NotUsed>>

public class BroadcastHub<T>
extends GraphStageWithMaterializedValue<SinkShape<T>,Source<T,NotUsed>>

INTERNAL API

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	BroadcastHub.ConsumerEvent
static interface	BroadcastHub.HubEvent
static interface	BroadcastHub.HubState

Nested classes/interfaces inherited from interface akka.stream.Graph

Graph.GraphMapMatVal<S extends Shape,M>

Constructor Summary

Constructors

Constructor	Description
BroadcastHub(int bufferSize)

Method Summary

Modifier and Type	Method	Description
scala.Tuple2<GraphStageLogic,Source<T,NotUsed>>	createLogicAndMaterializedValue(Attributes inheritedAttributes)
Inlet<T>	in()
SinkShape<T>	shape()	The shape of a graph is all that is externally visible: its inlets and outlets.
static <T> Sink<T,Source<T,NotUsed>>	sink()	Creates a Sink that receives elements from its upstream producer and broadcasts them to a dynamic set of consumers.
static <T> Sink<T,Source<T,NotUsed>>	sink(int bufferSize)	Creates a Sink that receives elements from its upstream producer and broadcasts them to a dynamic set of consumers.

Methods inherited from class akka.stream.stage.GraphStageWithMaterializedValue

createLogicAndMaterializedValue, initialAttributes, traversalBuilder, withAttributes

Methods inherited from class java.lang.Object

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

Methods inherited from interface akka.stream.Graph

addAttributes, async, async, async, named

Constructor Detail

BroadcastHub

public BroadcastHub(int bufferSize)

Method Detail

sink

public static <T> Sink<T,Source<T,NotUsed>> sink(int bufferSize)

Creates a Sink that receives elements from its upstream producer and broadcasts them to a dynamic set of consumers. After the Sink returned by this method is materialized, it returns a Source as materialized value. This Source can be materialized an arbitrary number of times and each materialization will receive the broadcast elements from the original Sink.

Every new materialization of the Sink results in a new, independent hub, which materializes to its own Source for consuming the Sink of that materialization.

If the original Sink is failed, then the failure is immediately propagated to all of its materialized Sources (possibly jumping over already buffered elements). If the original Sink is completed, then all corresponding Sources are completed. Both failure and normal completion is "remembered" and later materializations of the Source will see the same (failure or completion) state. Sources that are cancelled are simply removed from the dynamic set of consumers.

Parameters:

bufferSize - Buffer size used by the producer. Gives an upper bound on how "far" from each other two concurrent consumers can be in terms of element. If this buffer is full, the producer is backpressured. Must be a power of two and less than 4096.

sink

public static <T> Sink<T,Source<T,NotUsed>> sink()

Creates a Sink that receives elements from its upstream producer and broadcasts them to a dynamic set of consumers. After the Sink returned by this method is materialized, it returns a Source as materialized value. This Source can be materialized arbitrary many times and each materialization will receive the broadcast elements from the original Sink.

Every new materialization of the Sink results in a new, independent hub, which materializes to its own Source for consuming the Sink of that materialization.

If the original Sink is failed, then the failure is immediately propagated to all of its materialized Sources (possibly jumping over already buffered elements). If the original Sink is completed, then all corresponding Sources are completed. Both failure and normal completion is "remembered" and later materializations of the Source will see the same (failure or completion) state. Sources that are cancelled are simply removed from the dynamic set of consumers.

in

public Inlet<T> in()

shape

public SinkShape<T> shape()

Description copied from interface: Graph

The shape of a graph is all that is externally visible: its inlets and outlets.

createLogicAndMaterializedValue

public scala.Tuple2<GraphStageLogic,Source<T,NotUsed>> createLogicAndMaterializedValue(Attributes inheritedAttributes)

Specified by:

createLogicAndMaterializedValue in class GraphStageWithMaterializedValue<SinkShape<T>,Source<T,NotUsed>>