akka.stream.javadsl.MergeLatest.scala Maven / Gradle / Ivy
/*
* Copyright (C) 2018-2020 Lightbend Inc.
*/
package akka.stream.javadsl
import akka.stream.stage.GraphStage
import akka.stream.{ scaladsl, UniformFanInShape }
import akka.util.ccompat.JavaConverters._
/**
* MergeLatest joins elements from N input streams into stream of lists of size N.
* i-th element in list is the latest emitted element from i-th input stream.
* MergeLatest emits list for each element emitted from some input stream,
* but only after each stream emitted at least one element
*
* '''Emits when''' element is available from some input and each input emits at least one element from stream start
*
* '''Completes when''' all upstreams complete (eagerClose=false) or one upstream completes (eagerClose=true)
*
* '''Cancels when''' downstream cancels
*
*/
object MergeLatest {
/**
* Create a new `MergeLatest` with the specified number of input ports.
*
* @param inputPorts number of input ports
* @param eagerComplete if true, the merge latest will complete as soon as one of its inputs completes.
*/
def create[T](inputPorts: Int, eagerComplete: Boolean): GraphStage[UniformFanInShape[T, java.util.List[T]]] =
new scaladsl.MergeLatest[T, java.util.List[T]](inputPorts, eagerComplete)(x => x.toList.asJava)
/**
* Create a new `MergeLatest` with the specified number of input ports.
*
* @param inputPorts number of input ports
*/
def create[T](inputPorts: Int): GraphStage[UniformFanInShape[T, java.util.List[T]]] = create(inputPorts, false)
}