85 lines
2.5 KiB
Scala
85 lines
2.5 KiB
Scala
package docs.stream
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import akka.stream.{ OverflowStrategy, ActorFlowMaterializerSettings, ActorFlowMaterializer }
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import akka.stream.scaladsl._
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import akka.stream.testkit.AkkaSpec
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import akka.stream.OperationAttributes
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class StreamBuffersRateSpec extends AkkaSpec {
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implicit val mat = ActorFlowMaterializer()
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"Demonstrate pipelining" in {
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def println(s: Any) = ()
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//#pipelining
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Source(1 to 3)
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.map { i => println(s"A: $i"); i }
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.map { i => println(s"B: $i"); i }
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.map { i => println(s"C: $i"); i }
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.runWith(Sink.ignore)
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//#pipelining
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}
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"Demonstrate buffer sizes" in {
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//#materializer-buffer
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val materializer = ActorFlowMaterializer(
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ActorFlowMaterializerSettings(system)
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.withInputBuffer(
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initialSize = 64,
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maxSize = 64))
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//#materializer-buffer
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//#section-buffer
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val section = Flow[Int].map(_ * 2)
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.withAttributes(OperationAttributes.inputBuffer(initial = 1, max = 1))
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val flow = section.via(Flow[Int].map(_ / 2)) // the buffer size of this map is the default
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//#section-buffer
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}
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"buffering abstraction leak" in {
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//#buffering-abstraction-leak
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import scala.concurrent.duration._
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case class Tick()
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FlowGraph.closed() { implicit b =>
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import FlowGraph.Implicits._
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val zipper = b.add(ZipWith[Tick, Int, Int]((tick, count) => count))
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Source(initialDelay = 3.second, interval = 3.second, Tick()) ~> zipper.in0
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Source(initialDelay = 1.second, interval = 1.second, "message!")
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.conflate(seed = (_) => 1)((count, _) => count + 1) ~> zipper.in1
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zipper.out ~> Sink.foreach(println)
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}
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//#buffering-abstraction-leak
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}
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"explcit buffers" in {
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trait Job
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def inboundJobsConnector(): Source[Job, Unit] = Source.empty
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//#explicit-buffers-backpressure
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// Getting a stream of jobs from an imaginary external system as a Source
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val jobs: Source[Job, Unit] = inboundJobsConnector()
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jobs.buffer(1000, OverflowStrategy.backpressure)
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//#explicit-buffers-backpressure
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//#explicit-buffers-droptail
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jobs.buffer(1000, OverflowStrategy.dropTail)
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//#explicit-buffers-droptail
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//#explicit-buffers-drophead
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jobs.buffer(1000, OverflowStrategy.dropHead)
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//#explicit-buffers-drophead
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//#explicit-buffers-dropbuffer
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jobs.buffer(1000, OverflowStrategy.dropBuffer)
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//#explicit-buffers-dropbuffer
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//#explicit-buffers-fail
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jobs.buffer(1000, OverflowStrategy.fail)
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//#explicit-buffers-fail
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}
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}
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