54 lines
1.3 KiB
Scala
54 lines
1.3 KiB
Scala
/*
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* Copyright (C) 2018-2020 Lightbend Inc. <https://www.lightbend.com>
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*/
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package docs.stream.cookbook
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import akka.NotUsed
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import akka.stream.scaladsl.{ Flow, Sink, Source }
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import akka.stream.testkit._
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import scala.concurrent.duration._
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import akka.testkit.TestLatch
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import scala.concurrent.Await
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class RecipeSimpleDrop extends RecipeSpec {
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"Recipe for simply dropping elements for a faster stream" must {
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"work" in {
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//#simple-drop
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val droppyStream: Flow[Message, Message, NotUsed] =
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Flow[Message].conflate((lastMessage, newMessage) => newMessage)
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//#simple-drop
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val latch = TestLatch(2)
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val realDroppyStream =
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Flow[Message].conflate((lastMessage, newMessage) => { latch.countDown(); newMessage })
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val pub = TestPublisher.probe[Message]()
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val sub = TestSubscriber.manualProbe[Message]()
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val messageSource = Source.fromPublisher(pub)
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val sink = Sink.fromSubscriber(sub)
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messageSource.via(realDroppyStream).to(sink).run()
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val subscription = sub.expectSubscription()
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sub.expectNoMessage()
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pub.sendNext("1")
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pub.sendNext("2")
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pub.sendNext("3")
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Await.ready(latch, 1.second)
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subscription.request(1)
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sub.expectNext("3")
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pub.sendComplete()
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subscription.request(1)
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sub.expectComplete()
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}
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}
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}
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