akka.stream.scaladsl

Class Balance<T>

java.lang.Object

akka.stream.stage.GraphStageWithMaterializedValue<S,NotUsed>

akka.stream.stage.GraphStage<UniformFanOutShape<T,T>>

akka.stream.scaladsl.Balance<T>

All Implemented Interfaces:

Graph<UniformFanOutShape<T,T>,NotUsed>

public final class Balance<T>
extends GraphStage<UniformFanOutShape<T,T>>

Fan-out the stream to several streams. Each upstream element is emitted to the first available downstream consumer. It will not shut down until the subscriptions for at least two downstream subscribers have been established.

A Balance has one in port and 2 or more out ports.

'''Emits when''' any of the outputs stops backpressuring; emits the element to the first available output

'''Backpressures when''' all of the outputs backpressure

'''Completes when''' upstream completes

'''Cancels when''' all downstreams cancel

Constructor Summary

Constructors

Constructor and Description
Balance(int outputPorts, boolean waitForAllDownstreams)

Method Summary

Modifier and Type	Method and Description
static Graph<S,M>	addAttributes(Attributes attr)
static <T> Balance<T>	apply(int outputPorts, boolean waitForAllDownstreams) Create a new Balance with the specified number of output ports.
static Graph<S,M>	async()
GraphStageLogic	createLogic(Attributes inheritedAttributes)
static scala.Tuple2<GraphStageLogic,NotUsed>	createLogicAndMaterializedValue(Attributes inheritedAttributes)
Inlet<T>	in()
Attributes	initialAttributes()
static StreamLayout.Module	module()
static Graph<S,M>	named(java.lang.String name)
scala.collection.immutable.IndexedSeq<Outlet<T>>	out()
int	outputPorts()
UniformFanOutShape<T,T>	shape() The shape of a graph is all that is externally visible: its inlets and outlets.
java.lang.String	toString()
boolean	waitForAllDownstreams()
static Graph<S,M>	withAttributes(Attributes attr)

Methods inherited from class akka.stream.stage.GraphStage

createLogicAndMaterializedValue

Methods inherited from class akka.stream.stage.GraphStageWithMaterializedValue

module, withAttributes

Methods inherited from class java.lang.Object

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

Methods inherited from interface akka.stream.Graph

addAttributes, async, named

Constructor Detail

Balance

public Balance(int outputPorts,
               boolean waitForAllDownstreams)

Method Detail

apply

public static <T> Balance<T> apply(int outputPorts,
                                   boolean waitForAllDownstreams)

Create a new Balance with the specified number of output ports.

Parameters:

outputPorts - number of output ports

waitForAllDownstreams - if you use waitForAllDownstreams = true it will not start emitting elements to downstream outputs until all of them have requested at least one element, default value is false

Returns:

(undocumented)

named

public static Graph<S,M> named(java.lang.String name)

async

public static Graph<S,M> async()

addAttributes

public static Graph<S,M> addAttributes(Attributes attr)

module

public static final StreamLayout.Module module()

withAttributes

public static final Graph<S,M> withAttributes(Attributes attr)

createLogicAndMaterializedValue

public static final scala.Tuple2<GraphStageLogic,NotUsed> createLogicAndMaterializedValue(Attributes inheritedAttributes)

outputPorts

public int outputPorts()

waitForAllDownstreams

public boolean waitForAllDownstreams()

in

public Inlet<T> in()

out

public scala.collection.immutable.IndexedSeq<Outlet<T>> out()

initialAttributes

public Attributes initialAttributes()

Overrides:

initialAttributes in class GraphStageWithMaterializedValue<UniformFanOutShape<T,T>,NotUsed>

shape

public UniformFanOutShape<T,T> shape()

Description copied from interface: Graph

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

Returns:

(undocumented)

createLogic

public GraphStageLogic createLogic(Attributes inheritedAttributes)

Specified by:

createLogic in class GraphStage<UniformFanOutShape<T,T>>

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object