fold async emits zero given an empty stream #21562
This commit is contained in:
Vsevolod Belousov
Johan Andrén
parent
0b9a5026a0
commit
0e60020c58
3 changed files with 132 additions and 52 deletions
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@ -3,22 +3,20 @@
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*/
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package akka.stream.scaladsl
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import scala.util.control.NoStackTrace
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import scala.concurrent.{ Await, Future }
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import scala.concurrent.duration._
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import akka.NotUsed
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import akka.stream.ActorMaterializer
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import akka.stream.ActorAttributes.supervisionStrategy
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import akka.stream.Supervision.{ restartingDecider, resumingDecider }
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import akka.stream.ActorMaterializer
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import akka.stream.Supervision.{restartingDecider, resumingDecider}
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import akka.stream.impl.ReactiveStreamsCompliance
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import akka.testkit.{ AkkaSpec, TestLatch }
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import akka.stream.testkit._, Utils._
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import akka.stream.testkit.Utils._
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import akka.stream.testkit._
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import akka.testkit.TestLatch
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import org.scalatest.concurrent.PatienceConfiguration.Timeout
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import scala.concurrent.duration._
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import scala.concurrent.{Await, Future}
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import scala.util.control.NoStackTrace
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class FlowFoldAsyncSpec extends StreamSpec {
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implicit val materializer = ActorMaterializer()
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implicit def ec = materializer.executionContext
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@ -261,6 +259,22 @@ class FlowFoldAsyncSpec extends StreamSpec {
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upstream.expectCancellation()
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}
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"complete future and return zero given an empty stream" in assertAllStagesStopped {
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val futureValue =
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Source.fromIterator[Int](() ⇒ Iterator.empty)
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.runFoldAsync(0)((acc, elem) ⇒ Future.successful(acc + elem))
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Await.result(futureValue, remainingOrDefault) should be(0)
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}
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"complete future and return zero + item given a stream of one item" in assertAllStagesStopped {
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val futureValue =
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Source.single(100)
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.runFoldAsync(5)((acc, elem) ⇒ Future.successful(acc + elem))
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Await.result(futureValue, remainingOrDefault) should be(105)
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}
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}
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// Keep
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@ -56,6 +56,14 @@ class FlowFoldSpec extends StreamSpec {
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the[Exception] thrownBy Await.result(future, 3.seconds) should be(error)
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}
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"complete future and return zero given an empty stream" in assertAllStagesStopped {
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val futureValue =
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Source.fromIterator[Int](() ⇒ Iterator.empty)
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.runFold(0)(_ + _)
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Await.result(futureValue, 3.seconds) should be(0)
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}
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}
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}
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@ -30,6 +30,7 @@ final case class Map[In, Out](f: In ⇒ Out) extends GraphStage[FlowShape[In, Ou
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val in = Inlet[In]("Map.in")
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val out = Outlet[Out]("Map.out")
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override val shape = FlowShape(in, out)
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override def initialAttributes: Attributes = DefaultAttributes.map
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override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
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@ -131,6 +132,7 @@ final case class DropWhile[T](p: T ⇒ Boolean) extends GraphStage[FlowShape[T,
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val in = Inlet[T]("DropWhile.in")
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val out = Outlet[T]("DropWhile.out")
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override val shape = FlowShape(in, out)
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override def initialAttributes: Attributes = DefaultAttributes.dropWhile
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def createLogic(inheritedAttributes: Attributes) = new SupervisedGraphStageLogic(inheritedAttributes, shape) with InHandler with OutHandler {
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@ -150,9 +152,12 @@ final case class DropWhile[T](p: T ⇒ Boolean) extends GraphStage[FlowShape[T,
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}
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override def onResume(t: Throwable): Unit = if (!hasBeenPulled(in)) pull(in)
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override def onPull(): Unit = pull(in)
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setHandlers(in, out, this)
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}
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override def toString = "DropWhile"
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}
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@ -163,7 +168,9 @@ abstract class SupervisedGraphStageLogic(inheritedAttributes: Attributes, shape:
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private lazy val decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
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def withSupervision[T](f: () ⇒ T): Option[T] =
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try { Some(f()) } catch {
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try {
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Some(f())
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} catch {
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case NonFatal(ex) ⇒
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decider(ex) match {
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case Supervision.Stop ⇒ onStop(ex)
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@ -174,7 +181,9 @@ abstract class SupervisedGraphStageLogic(inheritedAttributes: Attributes, shape:
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}
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def onResume(t: Throwable): Unit
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def onStop(t: Throwable): Unit = failStage(t)
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def onRestart(t: Throwable): Unit = onResume(t)
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}
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@ -192,10 +201,13 @@ final case class Collect[In, Out](pf: PartialFunction[In, Out]) extends GraphSta
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val in = Inlet[In]("Collect.in")
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val out = Outlet[Out]("Collect.out")
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override val shape = FlowShape(in, out)
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override def initialAttributes: Attributes = DefaultAttributes.collect
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def createLogic(inheritedAttributes: Attributes) = new SupervisedGraphStageLogic(inheritedAttributes, shape) with InHandler with OutHandler {
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import Collect.NotApplied
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val wrappedPf = () ⇒ pf.applyOrElse(grab(in), NotApplied)
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override def onPush(): Unit = withSupervision(wrappedPf) match {
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@ -207,9 +219,12 @@ final case class Collect[In, Out](pf: PartialFunction[In, Out]) extends GraphSta
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}
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override def onResume(t: Throwable): Unit = if (!hasBeenPulled(in)) pull(in)
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override def onPull(): Unit = pull(in)
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setHandlers(in, out, this)
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}
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override def toString = "Collect"
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}
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@ -224,6 +239,7 @@ final case class Recover[T](pf: PartialFunction[Throwable, T]) extends GraphStag
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override protected val initialAttributes: Attributes = DefaultAttributes.recover
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override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
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import Collect.NotApplied
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var recovered: Option[T] = None
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@ -320,6 +336,7 @@ final case class Scan[In, Out](zero: Out, f: (Out, In) ⇒ Out) extends GraphSta
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override val shape = FlowShape[In, Out](Inlet("Scan.in"), Outlet("Scan.out"))
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override def initialAttributes: Attributes = DefaultAttributes.scan
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override def toString: String = "Scan"
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override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
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@ -342,6 +359,7 @@ final case class Scan[In, Out](zero: Out, f: (Out, In) ⇒ Out) extends GraphSta
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setHandler(in, new InHandler {
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override def onPush(): Unit = ()
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override def onUpstreamFinish(): Unit = setHandler(out, new OutHandler {
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override def onPull(): Unit = {
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push(out, aggregator)
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@ -351,6 +369,7 @@ final case class Scan[In, Out](zero: Out, f: (Out, In) ⇒ Out) extends GraphSta
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})
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override def onPull(): Unit = pull(in)
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override def onPush(): Unit = {
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try {
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aggregator = f(aggregator, grab(in))
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@ -426,6 +445,7 @@ final case class Fold[In, Out](zero: Out, f: (Out, In) ⇒ Out) extends GraphSta
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* INTERNAL API
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*/
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final class FoldAsync[In, Out](zero: Out, f: (Out, In) ⇒ Future[Out]) extends GraphStage[FlowShape[In, Out]] {
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import akka.dispatch.ExecutionContexts
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val in = Inlet[In]("FoldAsync.in")
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@ -436,30 +456,29 @@ final class FoldAsync[In, Out](zero: Out, f: (Out, In) ⇒ Future[Out]) extends
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override val initialAttributes = DefaultAttributes.foldAsync
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def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
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val decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
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def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
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new GraphStageLogic(shape) with InHandler with OutHandler {
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val decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
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private var aggregator: Out = zero
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private var aggregating: Future[Out] = Future.successful(aggregator)
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private var aggregator: Out = zero
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private var aggregating: Future[Out] = Future.successful(aggregator)
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private def onRestart(t: Throwable): Unit = {
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aggregator = zero
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}
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private def onRestart(t: Throwable): Unit = {
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aggregator = zero
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}
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private def ec = ExecutionContexts.sameThreadExecutionContext
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private def ec = ExecutionContexts.sameThreadExecutionContext
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private val futureCB = getAsyncCallback[Try[Out]]((result: Try[Out]) ⇒ {
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result match {
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case Success(update) if update != null ⇒ {
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private val futureCB = getAsyncCallback[Try[Out]] {
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case Success(update) if update != null ⇒
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aggregator = update
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if (isClosed(in)) {
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push(out, update)
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completeStage()
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} else if (isAvailable(out) && !hasBeenPulled(in)) tryPull(in)
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}
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case other ⇒ {
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case other ⇒
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val ex = other match {
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case Failure(t) ⇒ t
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case Success(s) if s == null ⇒
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@ -476,42 +495,45 @@ final class FoldAsync[In, Out](zero: Out, f: (Out, In) ⇒ Future[Out]) extends
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completeStage()
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} else if (isAvailable(out) && !hasBeenPulled(in)) tryPull(in)
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}
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}.invoke _
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def onPush(): Unit = {
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try {
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aggregating = f(aggregator, grab(in))
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handleAggregatingValue()
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} catch {
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case NonFatal(ex) ⇒ decider(ex) match {
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case Supervision.Stop ⇒ failStage(ex)
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case supervision ⇒ {
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supervision match {
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case Supervision.Restart ⇒ onRestart(ex)
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case _ ⇒ () // just ignore on Resume
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}
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tryPull(in)
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}
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}
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}
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}
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}).invoke _
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def onPush(): Unit = {
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try {
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aggregating = f(aggregator, grab(in))
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override def onUpstreamFinish(): Unit = {
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handleAggregatingValue()
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}
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def onPull(): Unit = if (!hasBeenPulled(in)) tryPull(in)
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private def handleAggregatingValue(): Unit = {
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aggregating.value match {
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case Some(result) ⇒ futureCB(result) // already completed
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case _ ⇒ aggregating.onComplete(futureCB)(ec)
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}
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} catch {
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case NonFatal(ex) ⇒ decider(ex) match {
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case Supervision.Stop ⇒ failStage(ex)
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case supervision ⇒ {
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supervision match {
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case Supervision.Restart ⇒ onRestart(ex)
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case _ ⇒ () // just ignore on Resume
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}
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tryPull(in)
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}
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}
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}
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setHandlers(in, out, this)
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override def toString =
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s"FoldAsync.Logic(completed=${aggregating.isCompleted})"
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}
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override def onUpstreamFinish(): Unit = {}
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def onPull(): Unit = if (!hasBeenPulled(in)) tryPull(in)
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setHandlers(in, out, this)
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override def toString =
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s"FoldAsync.Logic(completed=${aggregating.isCompleted})"
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}
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}
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/**
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@ -619,6 +641,7 @@ final case class LimitWeighted[T](val n: Long, val costFn: T ⇒ Long) extends G
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val in = Inlet[T]("LimitWeighted.in")
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val out = Outlet[T]("LimitWeighted.out")
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override val shape = FlowShape(in, out)
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override def initialAttributes: Attributes = DefaultAttributes.limitWeighted
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def createLogic(inheritedAttributes: Attributes) = new SupervisedGraphStageLogic(inheritedAttributes, shape) with InHandler with OutHandler {
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@ -633,14 +656,19 @@ final case class LimitWeighted[T](val n: Long, val costFn: T ⇒ Long) extends G
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case None ⇒ //do nothing
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}
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}
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override def onResume(t: Throwable): Unit = if (!hasBeenPulled(in)) pull(in)
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override def onRestart(t: Throwable): Unit = {
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left = n
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if (!hasBeenPulled(in)) pull(in)
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}
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override def onPull(): Unit = pull(in)
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setHandlers(in, out, this)
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}
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override def toString = "LimitWeighted"
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}
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@ -892,6 +920,7 @@ final class Expand[In, Out](val extrapolate: In ⇒ Iterator[Out]) extends Graph
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private val out = Outlet[Out]("expand.out")
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override def initialAttributes = DefaultAttributes.expand
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override val shape = FlowShape(in, out)
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override def createLogic(attr: Attributes) = new GraphStageLogic(shape) with InHandler with OutHandler {
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@ -941,6 +970,7 @@ final class Expand[In, Out](val extrapolate: In ⇒ Iterator[Out]) extends Graph
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* INTERNAL API
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*/
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private[akka] object MapAsync {
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final class Holder[T](var elem: Try[T], val cb: AsyncCallback[Holder[T]]) extends (Try[T] ⇒ Unit) {
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def setElem(t: Try[T]): Unit =
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elem = t match {
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@ -953,6 +983,7 @@ private[akka] object MapAsync {
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cb.invoke(this)
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}
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}
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val NotYetThere = Failure(new Exception)
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}
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@ -968,6 +999,7 @@ final case class MapAsync[In, Out](parallelism: Int, f: In ⇒ Future[Out])
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private val out = Outlet[Out]("MapAsync.out")
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override def initialAttributes = DefaultAttributes.mapAsync
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override val shape = FlowShape(in, out)
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override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
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@ -984,6 +1016,7 @@ final case class MapAsync[In, Out](parallelism: Int, f: In ⇒ Future[Out])
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case _ ⇒ if (isAvailable(out)) pushOne()
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}
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}
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val futureCB = getAsyncCallback[Holder[Out]](holderCompleted)
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private[this] def todo = buffer.used
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@ -1023,6 +1056,7 @@ final case class MapAsync[In, Out](parallelism: Int, f: In ⇒ Future[Out])
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}
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if (todo < parallelism && !hasBeenPulled(in)) tryPull(in)
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}
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override def onUpstreamFinish(): Unit = if (todo == 0) completeStage()
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override def onPull(): Unit = pushOne()
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@ -1041,6 +1075,7 @@ final case class MapAsyncUnordered[In, Out](parallelism: Int, f: In ⇒ Future[O
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private val out = Outlet[Out]("MapAsyncUnordered.out")
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override def initialAttributes = DefaultAttributes.mapAsyncUnordered
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override val shape = FlowShape(in, out)
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override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
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@ -1052,6 +1087,7 @@ final case class MapAsyncUnordered[In, Out](parallelism: Int, f: In ⇒ Future[O
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private var inFlight = 0
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private var buffer: BufferImpl[Out] = _
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private[this] def todo = inFlight + buffer.used
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override def preStart(): Unit = buffer = BufferImpl(parallelism, materializer)
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@ -1074,6 +1110,7 @@ final case class MapAsyncUnordered[In, Out](parallelism: Int, f: In ⇒ Future[O
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else if (!hasBeenPulled(in)) tryPull(in)
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}
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}
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private val futureCB = getAsyncCallback(futureCompleted)
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private val invokeFutureCB: Try[Out] ⇒ Unit = futureCB.invoke
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@ -1119,6 +1156,7 @@ final case class Log[T](
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// TODO more optimisations can be done here - prepare logOnPush function etc
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override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
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new GraphStageLogic(shape) with OutHandler with InHandler {
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import Log._
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private var logLevels: LogLevels = _
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@ -1221,9 +1259,13 @@ private[akka] object Log {
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* INTERNAL API
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*/
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private[stream] object TimerKeys {
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case object TakeWithinTimerKey
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case object DropWithinTimerKey
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case object GroupedWithinTimerKey
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}
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final class GroupedWithin[T](val n: Int, val d: FiniteDuration) extends GraphStage[FlowShape[T, immutable.Seq[T]]] {
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@ -1232,7 +1274,9 @@ final class GroupedWithin[T](val n: Int, val d: FiniteDuration) extends GraphSta
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val in = Inlet[T]("in")
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val out = Outlet[immutable.Seq[T]]("out")
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override def initialAttributes = DefaultAttributes.groupedWithin
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val shape = FlowShape(in, out)
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override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new TimerGraphStageLogic(shape) with InHandler with OutHandler {
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@ -1304,7 +1348,9 @@ final class GroupedWithin[T](val n: Int, val d: FiniteDuration) extends GraphSta
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final class Delay[T](val d: FiniteDuration, val strategy: DelayOverflowStrategy) extends SimpleLinearGraphStage[T] {
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private[this] def timerName = "DelayedTimer"
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override def initialAttributes: Attributes = DefaultAttributes.delay
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override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new TimerGraphStageLogic(shape) with InHandler with OutHandler {
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val size =
|
||||
inheritedAttributes.get[InputBuffer] match {
|
||||
|
|
@ -1418,6 +1464,7 @@ final class TakeWithin[T](val timeout: FiniteDuration) extends SimpleLinearGraph
|
|||
|
||||
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new TimerGraphStageLogic(shape) with InHandler with OutHandler {
|
||||
def onPush(): Unit = push(out, grab(in))
|
||||
|
||||
def onPull(): Unit = pull(in)
|
||||
|
||||
setHandler(in, this)
|
||||
|
|
@ -1461,7 +1508,8 @@ final class DropWithin[T](val timeout: FiniteDuration) extends SimpleLinearGraph
|
|||
final class Reduce[T](val f: (T, T) ⇒ T) extends SimpleLinearGraphStage[T] {
|
||||
override def initialAttributes: Attributes = DefaultAttributes.reduce
|
||||
|
||||
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler { self ⇒
|
||||
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
|
||||
self ⇒
|
||||
override def toString = s"Reduce.Logic(aggregator=$aggregator)"
|
||||
|
||||
var aggregator: T = _
|
||||
|
|
@ -1505,6 +1553,7 @@ private[stream] object RecoverWith {
|
|||
|
||||
final class RecoverWith[T, M](val maximumRetries: Int, val pf: PartialFunction[Throwable, Graph[SourceShape[T], M]]) extends SimpleLinearGraphStage[T] {
|
||||
require(maximumRetries >= -1, "number of retries must be non-negative or equal to -1")
|
||||
|
||||
override def initialAttributes = DefaultAttributes.recoverWith
|
||||
|
||||
override def createLogic(attr: Attributes) = new GraphStageLogic(shape) {
|
||||
|
|
@ -1512,6 +1561,7 @@ final class RecoverWith[T, M](val maximumRetries: Int, val pf: PartialFunction[T
|
|||
|
||||
setHandler(in, new InHandler {
|
||||
override def onPush(): Unit = push(out, grab(in))
|
||||
|
||||
override def onUpstreamFailure(ex: Throwable) = onFailure(ex)
|
||||
})
|
||||
|
||||
|
|
@ -1531,12 +1581,15 @@ final class RecoverWith[T, M](val maximumRetries: Int, val pf: PartialFunction[T
|
|||
|
||||
sinkIn.setHandler(new InHandler {
|
||||
override def onPush(): Unit = push(out, sinkIn.grab())
|
||||
|
||||
override def onUpstreamFinish(): Unit = completeStage()
|
||||
|
||||
override def onUpstreamFailure(ex: Throwable) = onFailure(ex)
|
||||
})
|
||||
|
||||
val outHandler = new OutHandler {
|
||||
override def onPull(): Unit = sinkIn.pull()
|
||||
|
||||
override def onDownstreamFinish(): Unit = sinkIn.cancel()
|
||||
}
|
||||
|
||||
|
|
@ -1556,13 +1609,16 @@ final class StatefulMapConcat[In, Out](val f: () ⇒ In ⇒ immutable.Iterable[O
|
|||
val in = Inlet[In]("StatefulMapConcat.in")
|
||||
val out = Outlet[Out]("StatefulMapConcat.out")
|
||||
override val shape = FlowShape(in, out)
|
||||
|
||||
override def initialAttributes: Attributes = DefaultAttributes.statefulMapConcat
|
||||
|
||||
def createLogic(inheritedAttributes: Attributes) = new GraphStageLogic(shape) with InHandler with OutHandler {
|
||||
lazy val decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
|
||||
var currentIterator: Iterator[Out] = _
|
||||
var plainFun = f()
|
||||
|
||||
def hasNext = if (currentIterator != null) currentIterator.hasNext else false
|
||||
|
||||
setHandlers(in, out, this)
|
||||
|
||||
def pushPull(): Unit =
|
||||
|
|
@ -1590,6 +1646,7 @@ final class StatefulMapConcat[In, Out](val f: () ⇒ In ⇒ immutable.Iterable[O
|
|||
}
|
||||
|
||||
override def onUpstreamFinish(): Unit = onFinish()
|
||||
|
||||
override def onPull(): Unit = pushPull()
|
||||
|
||||
private def restartState(): Unit = {
|
||||
|
|
@ -1597,6 +1654,7 @@ final class StatefulMapConcat[In, Out](val f: () ⇒ In ⇒ immutable.Iterable[O
|
|||
currentIterator = null
|
||||
}
|
||||
}
|
||||
|
||||
override def toString = "StatefulMapConcat"
|
||||
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue