interleave

Emits a specifiable number of elements from the original source, then from the provided source and repeats.

Signature

def interleave[U >: Out](that: Graph[SourceShape[U], _], segmentSize: Int): Repr[U]
def interleave[U >: Out](that: Graph[SourceShape[U], _], segmentSize: Int, eagerClose: Boolean): Repr[U]
def interleaveMat[U >: Out, Mat2, Mat3](that: Graph[SourceShape[U], Mat2], request: Int)(matF: (Mat, Mat2) => Mat3): ReprMat[U, Mat3]
def interleaveMat[U >: Out, Mat2, Mat3](that: Graph[SourceShape[U], Mat2], request: Int, eagerClose: Boolean)(matF: (Mat, Mat2) => Mat3): ReprMat[U, Mat3]

Description

Emits a specifiable number of elements from the original source, then from the provided source and repeats. If one source completes the rest of the other stream will be emitted.

emits when element is available from the currently consumed upstream

backpressures when upstream backpressures

completes when both upstreams have completed

Example

Scala

sourceimport akka.stream.scaladsl.Source
import akka.stream.scaladsl.Sink

val sourceA = Source(List(1, 2, 3, 4))
val sourceB = Source(List(10, 20, 30, 40))

sourceA.interleave(sourceB, segmentSize = 2).runWith(Sink.foreach(println))
//prints 1, 2, 10, 20, 3, 4, 30, 40

Java

sourceimport akka.stream.javadsl.Source;
import akka.stream.javadsl.Sink;
import java.util.Arrays;

Source<Integer, NotUsed> sourceA = Source.from(Arrays.asList(1, 2, 3, 4));
Source<Integer, NotUsed> sourceB = Source.from(Arrays.asList(10, 20, 30, 40));
sourceA.interleave(sourceB, 2).runWith(Sink.foreach(System.out::print), materializer);
// prints 1, 2, 10, 20, 3, 4, 30, 40