akka.stream.scaladsl

Class Sink$

java.lang.Object

akka.stream.scaladsl.Sink$

public class Sink$
extends java.lang.Object

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
Sink$()

Method Summary

Modifier and Type	Method and Description
<T> Sink<T,NotUsed>	actorRef(ActorRef ref, java.lang.Object onCompleteMessage) Sends the elements of the stream to the given ActorRef.
<T> Sink<T,NotUsed>	actorRefWithAck(ActorRef ref, java.lang.Object onInitMessage, java.lang.Object ackMessage, java.lang.Object onCompleteMessage, scala.Function1<java.lang.Throwable,java.lang.Object> onFailureMessage) Sends the elements of the stream to the given ActorRef that sends back back-pressure signal.
<T> Sink<T,ActorRef>	actorSubscriber(Props props) Creates a Sink that is materialized to an ActorRef which points to an Actor created according to the passed in Props.
<T> Sink<T,org.reactivestreams.Publisher<T>>	asPublisher(boolean fanout) A Sink that materializes into a Publisher.
<T> Sink<T,NotUsed>	cancelled() A Sink that immediately cancels its upstream after materialization.
<T,U> Sink<T,NotUsed>	combine(Sink<U,?> first, Sink<U,?> second, scala.collection.Seq<Sink<U,?>> rest, scala.Function1<java.lang.Object,Graph<UniformFanOutShape<T,U>,NotUsed>> strategy) Combine several sinks with fan-out strategy like Broadcast or Balance and returns Sink.
<U,T> Sink<T,scala.concurrent.Future<U>>	fold(U zero, scala.Function2<U,T,U> f) A Sink that will invoke the given function for every received element, giving it its previous output (or the given zero value) and the element as input.
<U,T> Sink<T,scala.concurrent.Future<U>>	foldAsync(U zero, scala.Function2<U,T,scala.concurrent.Future<U>> f) A Sink that will invoke the given asynchronous function for every received element, giving it its previous output (or the given zero value) and the element as input.
<T> Sink<T,scala.concurrent.Future<Done>>	foreach(scala.Function1<T,scala.runtime.BoxedUnit> f) A Sink that will invoke the given procedure for each received element.
<T> Sink<T,scala.concurrent.Future<Done>>	foreachParallel(int parallelism, scala.Function1<T,scala.runtime.BoxedUnit> f, scala.concurrent.ExecutionContext ec) A Sink that will invoke the given function to each of the elements as they pass in.
<T,M> Sink<T,M>	fromGraph(Graph<SinkShape<T>,M> g) A graph with the shape of a sink logically is a sink, this method makes it so also in type.
<T> Sink<T,NotUsed>	fromSubscriber(org.reactivestreams.Subscriber<T> subscriber) Helper to create Sink from Subscriber.
<T> Sink<T,scala.concurrent.Future<T>>	head() A Sink that materializes into a Future of the first value received.
<T> Sink<T,scala.concurrent.Future<scala.Option<T>>>	headOption() A Sink that materializes into a Future of the optional first value received.
Sink<java.lang.Object,scala.concurrent.Future<Done>>	ignore() A Sink that will consume the stream and discard the elements.
<T> Sink<T,scala.concurrent.Future<T>>	last() A Sink that materializes into a Future of the last value received.
<T> Sink<T,scala.concurrent.Future<scala.Option<T>>>	lastOption() A Sink that materializes into a Future of the optional last value received.
<T,M> Sink<T,scala.concurrent.Future<M>>	lazyInit(scala.Function1<T,scala.concurrent.Future<Sink<T,M>>> sinkFactory, scala.Function0<M> fallback) Creates a real Sink upon receiving the first element.
<T> Sink<T,NotUsed>	onComplete(scala.Function1<scala.util.Try<Done>,scala.runtime.BoxedUnit> callback) A Sink that when the flow is completed, either through a failure or normal completion, apply the provided function with Success or Failure.
<T> Sink<T,SinkQueueWithCancel<T>>	queue() Creates a Sink that is materialized as an SinkQueue.
<T> Sink<T,scala.concurrent.Future<T>>	reduce(scala.Function2<T,T,T> f) A Sink that will invoke the given function for every received element, giving it its previous output (from the second element) and the element as input.
<T> Sink<T,scala.concurrent.Future<scala.collection.immutable.Seq<T>>>	seq() A Sink that keeps on collecting incoming elements until upstream terminates.
<T> SinkShape<T>	shape(java.lang.String name) INTERNAL API

Methods inherited from class java.lang.Object

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

Field Detail

MODULE$

public static final Sink$ MODULE$

Static reference to the singleton instance of this Scala object.

Constructor Detail

Sink$

public Sink$()

Method Detail

shape

public <T> SinkShape<T> shape(java.lang.String name)

INTERNAL API

fromGraph

public <T,M> Sink<T,M> fromGraph(Graph<SinkShape<T>,M> g)

A graph with the shape of a sink logically is a sink, this method makes it so also in type.

Parameters:

g - (undocumented)

Returns:

(undocumented)

fromSubscriber

public <T> Sink<T,NotUsed> fromSubscriber(org.reactivestreams.Subscriber<T> subscriber)

Helper to create Sink from Subscriber.

Parameters:

subscriber - (undocumented)

Returns:

(undocumented)

cancelled

public <T> Sink<T,NotUsed> cancelled()

A Sink that immediately cancels its upstream after materialization.

Returns:

(undocumented)

head

public <T> Sink<T,scala.concurrent.Future<T>> head()

A Sink that materializes into a Future of the first value received. If the stream completes before signaling at least a single element, the Future will be failed with a NoSuchElementException. If the stream signals an error errors before signaling at least a single element, the Future will be failed with the streams exception.

See also headOption.

Returns:

(undocumented)

headOption

public <T> Sink<T,scala.concurrent.Future<scala.Option<T>>> headOption()

A Sink that materializes into a Future of the optional first value received. If the stream completes before signaling at least a single element, the value of the Future will be None. If the stream signals an error errors before signaling at least a single element, the Future will be failed with the streams exception.

See also head.

Returns:

(undocumented)

last

public <T> Sink<T,scala.concurrent.Future<T>> last()

A Sink that materializes into a Future of the last value received. If the stream completes before signaling at least a single element, the Future will be failed with a NoSuchElementException. If the stream signals an error errors before signaling at least a single element, the Future will be failed with the streams exception.

See also lastOption.

Returns:

(undocumented)

lastOption

public <T> Sink<T,scala.concurrent.Future<scala.Option<T>>> lastOption()

A Sink that materializes into a Future of the optional last value received. If the stream completes before signaling at least a single element, the value of the Future will be None. If the stream signals an error errors before signaling at least a single element, the Future will be failed with the streams exception.

See also last.

Returns:

(undocumented)

seq

public <T> Sink<T,scala.concurrent.Future<scala.collection.immutable.Seq<T>>> seq()

A Sink that keeps on collecting incoming elements until upstream terminates. As upstream may be unbounded, Flow[T].take or the stricter Flow[T].limit (and their variants) may be used to ensure boundedness. Materializes into a Future of Seq[T] containing all the collected elements. Seq is limited to Int.MaxValue elements, this Sink will cancel the stream after having received that many elements.

See also Flow.limit, Flow.limitWeighted, Flow.take, Flow.takeWithin, Flow.takeWhile

Returns:

(undocumented)

asPublisher

public <T> Sink<T,org.reactivestreams.Publisher<T>> asPublisher(boolean fanout)

A Sink that materializes into a Publisher.

If fanout is true, the materialized Publisher will support multiple Subscribers and the size of the inputBuffer configured for this stage becomes the maximum number of elements that the fastest Subscriber can be ahead of the slowest one before slowing the processing down due to back pressure.

If fanout is false then the materialized Publisher will only support a single Subscriber and reject any additional Subscribers.

Parameters:

fanout - (undocumented)

Returns:

(undocumented)

ignore

public Sink<java.lang.Object,scala.concurrent.Future<Done>> ignore()

A Sink that will consume the stream and discard the elements.

Returns:

(undocumented)

foreach

public <T> Sink<T,scala.concurrent.Future<Done>> foreach(scala.Function1<T,scala.runtime.BoxedUnit> f)

A Sink that will invoke the given procedure for each received element. The sink is materialized into a Future will be completed with Success when reaching the normal end of the stream, or completed with Failure if there is a failure signaled in the stream..

Parameters:

f - (undocumented)

Returns:

(undocumented)

combine

public <T,U> Sink<T,NotUsed> combine(Sink<U,?> first,
                                     Sink<U,?> second,
                                     scala.collection.Seq<Sink<U,?>> rest,
                                     scala.Function1<java.lang.Object,Graph<UniformFanOutShape<T,U>,NotUsed>> strategy)

Combine several sinks with fan-out strategy like Broadcast or Balance and returns Sink.

Parameters:

first - (undocumented)

second - (undocumented)

rest - (undocumented)

strategy - (undocumented)

Returns:

(undocumented)

foreachParallel

public <T> Sink<T,scala.concurrent.Future<Done>> foreachParallel(int parallelism,
                                                                 scala.Function1<T,scala.runtime.BoxedUnit> f,
                                                                 scala.concurrent.ExecutionContext ec)

A Sink that will invoke the given function to each of the elements as they pass in. The sink is materialized into a Future

If f throws an exception and the supervision decision is akka.stream.Supervision.Stop the Future will be completed with failure.

If f throws an exception and the supervision decision is akka.stream.Supervision.Resume or akka.stream.Supervision.Restart the element is dropped and the stream continues.

See also Flow.mapAsyncUnordered

Parameters:

parallelism - (undocumented)

f - (undocumented)

ec - (undocumented)

Returns:

(undocumented)

fold

public <U,T> Sink<T,scala.concurrent.Future<U>> fold(U zero,
                                                     scala.Function2<U,T,U> f)

A Sink that will invoke the given function for every received element, giving it its previous output (or the given zero value) and the element as input. The returned Future will be completed with value of the final function evaluation when the input stream ends, or completed with Failure if there is a failure signaled in the stream.

Parameters:

zero - (undocumented)

f - (undocumented)

Returns:

(undocumented)

See Also:

foldAsync(U, scala.Function2<U, T, scala.concurrent.Future<U>>)

foldAsync

public <U,T> Sink<T,scala.concurrent.Future<U>> foldAsync(U zero,
                                                          scala.Function2<U,T,scala.concurrent.Future<U>> f)

A Sink that will invoke the given asynchronous function for every received element, giving it its previous output (or the given zero value) and the element as input. The returned Future will be completed with value of the final function evaluation when the input stream ends, or completed with Failure if there is a failure signaled in the stream.

Parameters:

zero - (undocumented)

f - (undocumented)

Returns:

(undocumented)

See Also:

fold(U, scala.Function2<U, T, U>)

reduce

public <T> Sink<T,scala.concurrent.Future<T>> reduce(scala.Function2<T,T,T> f)

A Sink that will invoke the given function for every received element, giving it its previous output (from the second element) and the element as input. The returned Future will be completed with value of the final function evaluation when the input stream ends, or completed with Failure if there is a failure signaled in the stream.

If the stream is empty (i.e. completes before signalling any elements), the reduce stage will fail its downstream with a NoSuchElementException, which is semantically in-line with that Scala's standard library collections do in such situations.

Parameters:

f - (undocumented)

Returns:

(undocumented)

onComplete

public <T> Sink<T,NotUsed> onComplete(scala.Function1<scala.util.Try<Done>,scala.runtime.BoxedUnit> callback)

A Sink that when the flow is completed, either through a failure or normal completion, apply the provided function with Success or Failure.

Parameters:

callback - (undocumented)

Returns:

(undocumented)

actorRef

public <T> Sink<T,NotUsed> actorRef(ActorRef ref,
                                    java.lang.Object onCompleteMessage)

Sends the elements of the stream to the given ActorRef. If the target actor terminates the stream will be canceled. When the stream is completed successfully the given onCompleteMessage will be sent to the destination actor. When the stream is completed with failure a Status.Failure message will be sent to the destination actor.

It will request at most maxInputBufferSize number of elements from upstream, but there is no back-pressure signal from the destination actor, i.e. if the actor is not consuming the messages fast enough the mailbox of the actor will grow. For potentially slow consumer actors it is recommended to use a bounded mailbox with zero mailbox-push-timeout-time or use a rate limiting stage in front of this Sink.

Parameters:

ref - (undocumented)

onCompleteMessage - (undocumented)

Returns:

(undocumented)

actorRefWithAck

public <T> Sink<T,NotUsed> actorRefWithAck(ActorRef ref,
                                           java.lang.Object onInitMessage,
                                           java.lang.Object ackMessage,
                                           java.lang.Object onCompleteMessage,
                                           scala.Function1<java.lang.Throwable,java.lang.Object> onFailureMessage)

Sends the elements of the stream to the given ActorRef that sends back back-pressure signal. First element is always onInitMessage, then stream is waiting for acknowledgement message ackMessage from the given actor which means that it is ready to process elements. It also requires ackMessage message after each stream element to make backpressure work.

If the target actor terminates the stream will be canceled. When the stream is completed successfully the given onCompleteMessage will be sent to the destination actor. When the stream is completed with failure - result of onFailureMessage(throwable) function will be sent to the destination actor.

Parameters:

ref - (undocumented)

onInitMessage - (undocumented)

ackMessage - (undocumented)

onCompleteMessage - (undocumented)

onFailureMessage - (undocumented)

Returns:

(undocumented)

actorSubscriber

public <T> Sink<T,ActorRef> actorSubscriber(Props props)

Creates a Sink that is materialized to an ActorRef which points to an Actor created according to the passed in Props. Actor created by the props must be ActorSubscriber.

Parameters:

props - (undocumented)

Returns:

(undocumented)

queue

public <T> Sink<T,SinkQueueWithCancel<T>> queue()

Creates a Sink that is materialized as an SinkQueue. akka.stream.scaladsl.SinkQueue.pull method is pulling element from the stream and returns Future[Option[T}. Future completes when element is available.

Before calling pull method second time you need to wait until previous Future completes. Pull returns Failed future with ''IllegalStateException'' if previous future has not yet completed.

Sink will request at most number of elements equal to size of inputBuffer from upstream and then stop back pressure. You can configure size of input buffer by using Sink.withAttributes method.

For stream completion you need to pull all elements from SinkQueue including last None as completion marker

See also SinkQueueWithCancel

Returns:

(undocumented)

lazyInit

public <T,M> Sink<T,scala.concurrent.Future<M>> lazyInit(scala.Function1<T,scala.concurrent.Future<Sink<T,M>>> sinkFactory,
                                                         scala.Function0<M> fallback)

Creates a real Sink upon receiving the first element. Internal Sink will not be created if there are no elements, because of completion or error.

If sinkFactory throws an exception and the supervision decision is akka.stream.Supervision.Stop the Future will be completed with failure. For all other supervision options it will try to create sink with next element

fallback will be executed when there was no elements and completed is received from upstream.

Parameters:

sinkFactory - (undocumented)

fallback - (undocumented)

Returns:

(undocumented)