f29d7affbd
* also make factories more consistent by only offering FlowGraph.create() * also remove secondary (edge-based) FlowGraph.Builder DSL * also improve naming for conversions from Graph to Source/Flow/BidiFlow/Sink
48 lines
1.3 KiB
Scala
48 lines
1.3 KiB
Scala
package docs.stream.cookbook
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import akka.stream.FlowShape
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import akka.stream.scaladsl._
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import akka.testkit.TestProbe
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import scala.concurrent.Await
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import scala.concurrent.duration._
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class RecipeWorkerPool extends RecipeSpec {
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"Recipe for a pool of workers" must {
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"work" in {
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val myJobs = Source(List("1", "2", "3", "4", "5"))
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type Result = String
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val worker = Flow[String].map(_ + " done")
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//#worker-pool
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def balancer[In, Out](worker: Flow[In, Out, Any], workerCount: Int): Flow[In, Out, Unit] = {
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import FlowGraph.Implicits._
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Flow.fromGraph(FlowGraph.create() { implicit b =>
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val balancer = b.add(Balance[In](workerCount, waitForAllDownstreams = true))
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val merge = b.add(Merge[Out](workerCount))
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for (_ <- 1 to workerCount) {
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// for each worker, add an edge from the balancer to the worker, then wire
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// it to the merge element
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balancer ~> worker ~> merge
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}
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FlowShape(balancer.in, merge.out)
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})
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}
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val processedJobs: Source[Result, Unit] = myJobs.via(balancer(worker, 3))
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//#worker-pool
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Await.result(processedJobs.grouped(10).runWith(Sink.head), 3.seconds).toSet should be(Set(
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"1 done", "2 done", "3 done", "4 done", "5 done"))
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}
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}
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}
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