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/**
* Copyright (C) 2009-2017 Lightbend Inc.
*/
package akka.stream.impl.fusing
import java.util.concurrent.TimeUnit.NANOSECONDS
import akka.annotation.{ DoNotInherit, InternalApi }
import akka.event.Logging.LogLevel
import akka.event.{ LogSource, Logging, LoggingAdapter }
import akka.stream.Attributes.{ InputBuffer, LogLevels }
import akka.stream.OverflowStrategies._
import akka.stream.impl.fusing.GraphStages.SimpleLinearGraphStage
import akka.stream.impl.{ ReactiveStreamsCompliance, Stages, Buffer ⇒ BufferImpl }
import akka.stream.scaladsl.{ Source, SourceQueue }
import akka.stream.stage._
import akka.stream.{ Supervision, _ }
import scala.annotation.tailrec
import scala.collection.immutable
import scala.collection.immutable.VectorBuilder
import scala.concurrent.Future
import scala.util.control.NonFatal
import scala.util.{ Failure, Success, Try }
import akka.stream.ActorAttributes.SupervisionStrategy
import scala.concurrent.duration.{ FiniteDuration, _ }
import akka.stream.impl.Stages.DefaultAttributes
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Map[In, Out](f: In ⇒ Out) extends GraphStage[FlowShape[In, Out]] {
val in = Inlet[In]("Map.in")
val out = Outlet[Out]("Map.out")
override val shape = FlowShape(in, out)
override def initialAttributes: Attributes = DefaultAttributes.map
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
new GraphStageLogic(shape) with InHandler with OutHandler {
private def decider =
inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
override def onPush(): Unit = {
try {
push(out, f(grab(in)))
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case _ ⇒ pull(in)
}
}
}
override def onPull(): Unit = pull(in)
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Filter[T](p: T ⇒ Boolean) extends SimpleLinearGraphStage[T] {
override def initialAttributes: Attributes = DefaultAttributes.filter
override def toString: String = "Filter"
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
new GraphStageLogic(shape) with OutHandler with InHandler {
def decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
override def onPush(): Unit = {
try {
val elem = grab(in)
if (p(elem)) {
push(out, elem)
} else {
pull(in)
}
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case _ ⇒ pull(in)
}
}
}
override def onPull(): Unit = pull(in)
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class TakeWhile[T](p: T ⇒ Boolean, inclusive: Boolean = false) extends SimpleLinearGraphStage[T] {
override def initialAttributes: Attributes = DefaultAttributes.takeWhile
override def toString: String = "TakeWhile"
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
new GraphStageLogic(shape) with OutHandler with InHandler {
override def toString = "TakeWhileLogic"
def decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
override def onPush(): Unit = {
try {
val elem = grab(in)
if (p(elem)) {
push(out, elem)
} else {
if (inclusive) push(out, elem)
completeStage()
}
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case _ ⇒ pull(in)
}
}
}
override def onPull(): Unit = pull(in)
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class DropWhile[T](p: T ⇒ Boolean) extends SimpleLinearGraphStage[T] {
override def initialAttributes: Attributes = DefaultAttributes.dropWhile
def createLogic(inheritedAttributes: Attributes) = new SupervisedGraphStageLogic(inheritedAttributes, shape) with InHandler with OutHandler {
override def onPush(): Unit = {
val elem = grab(in)
withSupervision(() ⇒ p(elem)) match {
case Some(flag) if flag ⇒ pull(in)
case Some(flag) if !flag ⇒
push(out, elem)
setHandler(in, rest)
case None ⇒ // do nothing
}
}
def rest = new InHandler {
def onPush() = push(out, grab(in))
}
override def onResume(t: Throwable): Unit = if (!hasBeenPulled(in)) pull(in)
override def onPull(): Unit = pull(in)
setHandlers(in, out, this)
}
override def toString = "DropWhile"
}
/**
* INTERNAL API
*/
@DoNotInherit private[akka] abstract class SupervisedGraphStageLogic(inheritedAttributes: Attributes, shape: Shape) extends GraphStageLogic(shape) {
private lazy val decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
def withSupervision[T](f: () ⇒ T): Option[T] =
try {
Some(f())
} catch {
case NonFatal(ex) ⇒
decider(ex) match {
case Supervision.Stop ⇒ onStop(ex)
case Supervision.Resume ⇒ onResume(ex)
case Supervision.Restart ⇒ onRestart(ex)
}
None
}
def onResume(t: Throwable): Unit
def onStop(t: Throwable): Unit = failStage(t)
def onRestart(t: Throwable): Unit = onResume(t)
}
private[stream] object Collect {
// Cached function that can be used with PartialFunction.applyOrElse to ensure that A) the guard is only applied once,
// and the caller can check the returned value with Collect.notApplied to query whether the PF was applied or not.
// Prior art: https://github.com/scala/scala/blob/v2.11.4/src/library/scala/collection/immutable/List.scala#L458
final val NotApplied: Any ⇒ Any = _ ⇒ Collect.NotApplied
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Collect[In, Out](pf: PartialFunction[In, Out]) extends GraphStage[FlowShape[In, Out]] {
val in = Inlet[In]("Collect.in")
val out = Outlet[Out]("Collect.out")
override val shape = FlowShape(in, out)
override def initialAttributes: Attributes = DefaultAttributes.collect
def createLogic(inheritedAttributes: Attributes) = new SupervisedGraphStageLogic(inheritedAttributes, shape) with InHandler with OutHandler {
import Collect.NotApplied
val wrappedPf = () ⇒ pf.applyOrElse(grab(in), NotApplied)
override def onPush(): Unit = withSupervision(wrappedPf) match {
case Some(result) ⇒ result match {
case NotApplied ⇒ pull(in)
case result: Out @unchecked ⇒ push(out, result)
}
case None ⇒ //do nothing
}
override def onResume(t: Throwable): Unit = if (!hasBeenPulled(in)) pull(in)
override def onPull(): Unit = pull(in)
setHandlers(in, out, this)
}
override def toString = "Collect"
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Recover[T](pf: PartialFunction[Throwable, T]) extends SimpleLinearGraphStage[T] {
override protected def initialAttributes: Attributes = DefaultAttributes.recover
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
import Collect.NotApplied
var recovered: Option[T] = None
override def onPush(): Unit = {
push(out, grab(in))
}
override def onPull(): Unit = {
recovered match {
case Some(elem) ⇒
push(out, elem)
completeStage()
case None ⇒
pull(in)
}
}
override def onUpstreamFailure(ex: Throwable): Unit = {
pf.applyOrElse(ex, NotApplied) match {
case NotApplied ⇒ failStage(ex)
case result: T @unchecked ⇒ {
if (isAvailable(out)) {
push(out, result)
completeStage()
} else {
recovered = Some(result)
}
}
}
}
setHandlers(in, out, this)
}
}
/**
* Maps error with the provided function if it is defined for an error or, otherwise, passes it on unchanged.
*
* While similar to [[Recover]] this stage can be used to transform an error signal to a different one *without* logging
* it as an error in the process. So in that sense it is NOT exactly equivalent to `recover(t => throw t2)` since recover
* would log the `t2` error.
*/
@InternalApi private[akka] final case class MapError[T](f: PartialFunction[Throwable, Throwable]) extends SimpleLinearGraphStage[T] {
override def createLogic(attr: Attributes) =
new GraphStageLogic(shape) with InHandler with OutHandler {
override def onPush(): Unit = push(out, grab(in))
override def onUpstreamFailure(ex: Throwable): Unit =
if (f.isDefinedAt(ex)) super.onUpstreamFailure(f(ex))
else super.onUpstreamFailure(ex)
override def onPull(): Unit = pull(in)
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Take[T](count: Long) extends SimpleLinearGraphStage[T] {
override def initialAttributes: Attributes = DefaultAttributes.take
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
private var left: Long = count
override def onPush(): Unit = {
if (left > 0) {
push(out, grab(in))
left -= 1
}
if (left <= 0) completeStage()
}
override def onPull(): Unit = {
if (left > 0) pull(in)
else completeStage()
}
setHandlers(in, out, this)
}
override def toString: String = "Take"
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Drop[T](count: Long) extends SimpleLinearGraphStage[T] {
override def initialAttributes: Attributes = DefaultAttributes.drop
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
private var left: Long = count
override def onPush(): Unit = {
if (left > 0) {
left -= 1
pull(in)
} else push(out, grab(in))
}
override def onPull(): Unit = pull(in)
setHandlers(in, out, this)
}
override def toString: String = "Drop"
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Scan[In, Out](zero: Out, f: (Out, In) ⇒ Out) extends GraphStage[FlowShape[In, Out]] {
override val shape = FlowShape[In, Out](Inlet("Scan.in"), Outlet("Scan.out"))
override def initialAttributes: Attributes = DefaultAttributes.scan
override def toString: String = "Scan"
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
new GraphStageLogic(shape) with InHandler with OutHandler {
self ⇒
private var aggregator = zero
private lazy val decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
import Supervision.{ Stop, Resume, Restart }
import shape.{ in, out }
// Initial behavior makes sure that the zero gets flushed if upstream is empty
setHandler(out, new OutHandler {
override def onPull(): Unit = {
push(out, aggregator)
setHandlers(in, out, self)
}
})
setHandler(in, new InHandler {
override def onPush(): Unit = ()
override def onUpstreamFinish(): Unit = setHandler(out, new OutHandler {
override def onPull(): Unit = {
push(out, aggregator)
completeStage()
}
})
})
override def onPull(): Unit = pull(in)
override def onPush(): Unit = {
try {
aggregator = f(aggregator, grab(in))
push(out, aggregator)
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Resume ⇒ if (!hasBeenPulled(in)) pull(in)
case Stop ⇒ failStage(ex)
case Restart ⇒
aggregator = zero
push(out, aggregator)
}
}
}
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class ScanAsync[In, Out](zero: Out, f: (Out, In) ⇒ Future[Out]) extends GraphStage[FlowShape[In, Out]] {
import akka.dispatch.ExecutionContexts
val in = Inlet[In]("ScanAsync.in")
val out = Outlet[Out]("ScanAsync.out")
override val shape: FlowShape[In, Out] = FlowShape[In, Out](in, out)
override val initialAttributes: Attributes = Attributes.name("scanAsync")
override val toString: String = "ScanAsync"
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
new GraphStageLogic(shape) with InHandler with OutHandler {
self ⇒
private var current: Out = zero
private var eventualCurrent: Future[Out] = Future.successful(current)
private def ec = ExecutionContexts.sameThreadExecutionContext
private lazy val decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
private val ZeroHandler: OutHandler with InHandler = new OutHandler with InHandler {
override def onPush(): Unit = ()
override def onPull(): Unit = {
push(out, current)
setHandlers(in, out, self)
}
override def onUpstreamFinish(): Unit = setHandler(out, new OutHandler {
override def onPull(): Unit = {
push(out, current)
completeStage()
}
})
}
private def onRestart(t: Throwable): Unit = {
current = zero
}
private def safePull(): Unit = {
if (!hasBeenPulled(in)) {
tryPull(in)
}
}
private def pushAndPullOrFinish(update: Out): Unit = {
push(out, update)
if (isClosed(in)) {
completeStage()
} else if (isAvailable(out)) {
safePull()
}
}
private def doSupervision(t: Throwable): Unit = {
decider(t) match {
case Supervision.Stop ⇒ failStage(t)
case Supervision.Resume ⇒ safePull()
case Supervision.Restart ⇒
onRestart(t)
safePull()
}
}
private val futureCB = getAsyncCallback[Try[Out]] {
case Success(next) if next != null ⇒
current = next
pushAndPullOrFinish(next)
case Success(null) ⇒ doSupervision(ReactiveStreamsCompliance.elementMustNotBeNullException)
case Failure(t) ⇒ doSupervision(t)
}.invoke _
setHandlers(in, out, ZeroHandler)
def onPull(): Unit = safePull()
def onPush(): Unit = {
try {
eventualCurrent = f(current, grab(in))
eventualCurrent.value match {
case Some(result) ⇒ futureCB(result)
case _ ⇒ eventualCurrent.onComplete(futureCB)(ec)
}
} catch {
case NonFatal(ex) ⇒
decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case Supervision.Restart ⇒ onRestart(ex)
case Supervision.Resume ⇒ ()
}
tryPull(in)
}
}
override def onUpstreamFinish(): Unit = {}
override val toString: String = s"ScanAsync.Logic(completed=${eventualCurrent.isCompleted})"
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Fold[In, Out](zero: Out, f: (Out, In) ⇒ Out) extends GraphStage[FlowShape[In, Out]] {
val in = Inlet[In]("Fold.in")
val out = Outlet[Out]("Fold.out")
override val shape: FlowShape[In, Out] = FlowShape(in, out)
override def toString: String = "Fold"
override val initialAttributes = DefaultAttributes.fold
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
new GraphStageLogic(shape) with InHandler with OutHandler {
private var aggregator: Out = zero
private def decider =
inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
override def onPush(): Unit = {
val elem = grab(in)
try {
aggregator = f(aggregator, elem)
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case Supervision.Restart ⇒ aggregator = zero
case _ ⇒ ()
}
} finally {
if (!isClosed(in)) pull(in)
}
}
override def onPull(): Unit = {
if (isClosed(in)) {
push(out, aggregator)
completeStage()
} else {
pull(in)
}
}
override def onUpstreamFinish(): Unit = {
if (isAvailable(out)) {
push(out, aggregator)
completeStage()
}
}
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final class FoldAsync[In, Out](zero: Out, f: (Out, In) ⇒ Future[Out]) extends GraphStage[FlowShape[In, Out]] {
import akka.dispatch.ExecutionContexts
val in = Inlet[In]("FoldAsync.in")
val out = Outlet[Out]("FoldAsync.out")
val shape = FlowShape.of(in, out)
override def toString: String = "FoldAsync"
override val initialAttributes = DefaultAttributes.foldAsync
def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
new GraphStageLogic(shape) with InHandler with OutHandler {
val decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
private var aggregator: Out = zero
private var aggregating: Future[Out] = Future.successful(aggregator)
private def onRestart(t: Throwable): Unit = {
aggregator = zero
}
private def ec = ExecutionContexts.sameThreadExecutionContext
private val futureCB = getAsyncCallback[Try[Out]] {
case Success(update) if update != null ⇒
aggregator = update
if (isClosed(in)) {
push(out, update)
completeStage()
} else if (isAvailable(out) && !hasBeenPulled(in)) tryPull(in)
case other ⇒
val ex = other match {
case Failure(t) ⇒ t
case Success(s) if s == null ⇒
ReactiveStreamsCompliance.elementMustNotBeNullException
}
val supervision = decider(ex)
if (supervision == Supervision.Stop) failStage(ex)
else {
if (supervision == Supervision.Restart) onRestart(ex)
if (isClosed(in)) {
push(out, aggregator)
completeStage()
} else if (isAvailable(out) && !hasBeenPulled(in)) tryPull(in)
}
}.invoke _
def onPush(): Unit = {
try {
aggregating = f(aggregator, grab(in))
handleAggregatingValue()
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case supervision ⇒ {
supervision match {
case Supervision.Restart ⇒ onRestart(ex)
case _ ⇒ () // just ignore on Resume
}
tryPull(in)
}
}
}
}
override def onUpstreamFinish(): Unit = {
handleAggregatingValue()
}
def onPull(): Unit = if (!hasBeenPulled(in)) tryPull(in)
private def handleAggregatingValue(): Unit = {
aggregating.value match {
case Some(result) ⇒ futureCB(result) // already completed
case _ ⇒ aggregating.onComplete(futureCB)(ec)
}
}
setHandlers(in, out, this)
override def toString =
s"FoldAsync.Logic(completed=${aggregating.isCompleted})"
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Intersperse[T](start: Option[T], inject: T, end: Option[T]) extends SimpleLinearGraphStage[T] {
ReactiveStreamsCompliance.requireNonNullElement(inject)
if (start.isDefined) ReactiveStreamsCompliance.requireNonNullElement(start.get)
if (end.isDefined) ReactiveStreamsCompliance.requireNonNullElement(end.get)
override def createLogic(attr: Attributes): GraphStageLogic = new GraphStageLogic(shape) with OutHandler {
val startInHandler = new InHandler {
override def onPush(): Unit = {
// if else (to avoid using Iterator[T].flatten in hot code)
if (start.isDefined) emitMultiple(out, Iterator(start.get, grab(in)))
else emit(out, grab(in))
setHandler(in, restInHandler) // switch handler
}
override def onUpstreamFinish(): Unit = {
emitMultiple(out, Iterator(start, end).flatten)
completeStage()
}
}
val restInHandler = new InHandler {
override def onPush(): Unit = emitMultiple(out, Iterator(inject, grab(in)))
override def onUpstreamFinish(): Unit = {
if (end.isDefined) emit(out, end.get)
completeStage()
}
}
def onPull(): Unit = pull(in)
setHandler(in, startInHandler)
setHandler(out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Grouped[T](n: Int) extends GraphStage[FlowShape[T, immutable.Seq[T]]] {
require(n > 0, "n must be greater than 0")
val in = Inlet[T]("Grouped.in")
val out = Outlet[immutable.Seq[T]]("Grouped.out")
override val shape: FlowShape[T, immutable.Seq[T]] = FlowShape(in, out)
override protected val initialAttributes: Attributes = DefaultAttributes.grouped
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
private val buf = {
val b = Vector.newBuilder[T]
b.sizeHint(n)
b
}
var left = n
override def onPush(): Unit = {
buf += grab(in)
left -= 1
if (left == 0) {
val elements = buf.result()
buf.clear()
left = n
push(out, elements)
} else {
pull(in)
}
}
override def onPull(): Unit = {
pull(in)
}
override def onUpstreamFinish(): Unit = {
// This means the buf is filled with some elements but not enough (left < n) to group together.
// Since the upstream has finished we have to push them to downstream though.
if (left < n) {
val elements = buf.result()
buf.clear()
left = n
push(out, elements)
}
completeStage()
}
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class LimitWeighted[T](val n: Long, val costFn: T ⇒ Long) extends SimpleLinearGraphStage[T] {
override def initialAttributes: Attributes = DefaultAttributes.limitWeighted
def createLogic(inheritedAttributes: Attributes) = new SupervisedGraphStageLogic(inheritedAttributes, shape) with InHandler with OutHandler {
private var left = n
override def onPush(): Unit = {
val elem = grab(in)
withSupervision(() ⇒ costFn(elem)) match {
case Some(weight) ⇒
left -= weight
if (left >= 0) push(out, elem) else failStage(new StreamLimitReachedException(n))
case None ⇒ //do nothing
}
}
override def onResume(t: Throwable): Unit = if (!hasBeenPulled(in)) pull(in)
override def onRestart(t: Throwable): Unit = {
left = n
if (!hasBeenPulled(in)) pull(in)
}
override def onPull(): Unit = pull(in)
setHandlers(in, out, this)
}
override def toString = "LimitWeighted"
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Sliding[T](val n: Int, val step: Int) extends GraphStage[FlowShape[T, immutable.Seq[T]]] {
require(n > 0, "n must be greater than 0")
require(step > 0, "step must be greater than 0")
val in = Inlet[T]("Sliding.in")
val out = Outlet[immutable.Seq[T]]("Sliding.out")
override val shape: FlowShape[T, immutable.Seq[T]] = FlowShape(in, out)
override protected val initialAttributes: Attributes = DefaultAttributes.sliding
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
private var buf = Vector.empty[T]
override def onPush(): Unit = {
buf :+= grab(in)
if (buf.size < n) {
pull(in)
} else if (buf.size == n) {
push(out, buf)
} else if (step <= n) {
buf = buf.drop(step)
if (buf.size == n) {
push(out, buf)
} else pull(in)
} else if (step > n) {
if (buf.size == step) {
buf = buf.drop(step)
}
pull(in)
}
}
override def onPull(): Unit = {
pull(in)
}
override def onUpstreamFinish(): Unit = {
// We can finish current stage directly if:
// 1. the buf is empty or
// 2. when the step size is greater than the sliding size (step > n) and current stage is in between
// two sliding (ie. buf.size >= n && buf.size < step).
//
// Otherwise it means there is still a not finished sliding so we have to push them before finish current stage.
if (buf.size < n && buf.size > 0) {
push(out, buf)
}
completeStage()
}
this.setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Buffer[T](size: Int, overflowStrategy: OverflowStrategy) extends SimpleLinearGraphStage[T] {
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
private var buffer: BufferImpl[T] = _
val enqueueAction: T ⇒ Unit =
overflowStrategy match {
case DropHead ⇒ elem ⇒
if (buffer.isFull) buffer.dropHead()
buffer.enqueue(elem)
pull(in)
case DropTail ⇒ elem ⇒
if (buffer.isFull) buffer.dropTail()
buffer.enqueue(elem)
pull(in)
case DropBuffer ⇒ elem ⇒
if (buffer.isFull) buffer.clear()
buffer.enqueue(elem)
pull(in)
case DropNew ⇒ elem ⇒
if (!buffer.isFull) buffer.enqueue(elem)
pull(in)
case Backpressure ⇒ elem ⇒
buffer.enqueue(elem)
if (!buffer.isFull) pull(in)
case Fail ⇒ elem ⇒
if (buffer.isFull) failStage(new BufferOverflowException(s"Buffer overflow (max capacity was: $size)!"))
else {
buffer.enqueue(elem)
pull(in)
}
}
override def preStart(): Unit = {
buffer = BufferImpl(size, materializer)
pull(in)
}
override def onPush(): Unit = {
val elem = grab(in)
// If out is available, then it has been pulled but no dequeued element has been delivered.
// It means the buffer at this moment is definitely empty,
// so we just push the current element to out, then pull.
if (isAvailable(out)) {
push(out, elem)
pull(in)
} else {
enqueueAction(elem)
}
}
override def onPull(): Unit = {
if (buffer.nonEmpty) push(out, buffer.dequeue())
if (isClosed(in)) {
if (buffer.isEmpty) completeStage()
} else if (!hasBeenPulled(in)) {
pull(in)
}
}
override def onUpstreamFinish(): Unit = {
if (buffer.isEmpty) completeStage()
}
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Batch[In, Out](val max: Long, val costFn: In ⇒ Long, val seed: In ⇒ Out, val aggregate: (Out, In) ⇒ Out)
extends GraphStage[FlowShape[In, Out]] {
val in = Inlet[In]("Batch.in")
val out = Outlet[Out]("Batch.out")
override val shape: FlowShape[In, Out] = FlowShape.of(in, out)
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
lazy val decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
private var agg: Out = null.asInstanceOf[Out]
private var left: Long = max
private var pending: In = null.asInstanceOf[In]
private def flush(): Unit = {
if (agg != null) {
push(out, agg)
left = max
}
if (pending != null) {
try {
agg = seed(pending)
left -= costFn(pending)
pending = null.asInstanceOf[In]
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case Supervision.Restart ⇒ restartState()
case Supervision.Resume ⇒
pending = null.asInstanceOf[In]
}
}
} else {
agg = null.asInstanceOf[Out]
}
}
override def preStart() = pull(in)
def onPush(): Unit = {
val elem = grab(in)
val cost = costFn(elem)
if (agg == null) {
try {
agg = seed(elem)
left -= cost
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case Supervision.Restart ⇒
restartState()
case Supervision.Resume ⇒
}
}
} else if (left < cost) {
pending = elem
} else {
try {
agg = aggregate(agg, elem)
left -= cost
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case Supervision.Restart ⇒
restartState()
case Supervision.Resume ⇒
}
}
}
if (isAvailable(out)) flush()
if (pending == null) pull(in)
}
override def onUpstreamFinish(): Unit = {
if (agg == null) completeStage()
}
def onPull(): Unit = {
if (agg == null) {
if (isClosed(in)) completeStage()
else if (!hasBeenPulled(in)) pull(in)
} else if (isClosed(in)) {
push(out, agg)
if (pending == null) completeStage()
else {
try {
agg = seed(pending)
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case Supervision.Resume ⇒
case Supervision.Restart ⇒
restartState()
if (!hasBeenPulled(in)) pull(in)
}
}
pending = null.asInstanceOf[In]
}
} else {
flush()
if (!hasBeenPulled(in)) pull(in)
}
}
private def restartState(): Unit = {
agg = null.asInstanceOf[Out]
left = max
pending = null.asInstanceOf[In]
}
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final class Expand[In, Out](val extrapolate: In ⇒ Iterator[Out]) extends GraphStage[FlowShape[In, Out]] {
private val in = Inlet[In]("expand.in")
private val out = Outlet[Out]("expand.out")
override def initialAttributes = DefaultAttributes.expand
override val shape = FlowShape(in, out)
override def createLogic(attr: Attributes) = new GraphStageLogic(shape) with InHandler with OutHandler {
private var iterator: Iterator[Out] = Iterator.empty
private var expanded = false
override def preStart(): Unit = pull(in)
def onPush(): Unit = {
iterator = extrapolate(grab(in))
if (iterator.hasNext) {
if (isAvailable(out)) {
expanded = true
pull(in)
push(out, iterator.next())
} else expanded = false
} else pull(in)
}
override def onUpstreamFinish(): Unit = {
if (iterator.hasNext && !expanded) () // need to wait
else completeStage()
}
def onPull(): Unit = {
if (iterator.hasNext) {
if (!expanded) {
expanded = true
if (isClosed(in)) {
push(out, iterator.next())
completeStage()
} else {
// expand needs to pull first to be “fair” when upstream is not actually slow
pull(in)
push(out, iterator.next())
}
} else push(out, iterator.next())
}
}
setHandler(in, this)
setHandler(out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] object MapAsync {
final class Holder[T](var elem: Try[T], val cb: AsyncCallback[Holder[T]]) extends (Try[T] ⇒ Unit) {
def setElem(t: Try[T]): Unit =
elem = t match {
case Success(null) ⇒ Failure[T](ReactiveStreamsCompliance.elementMustNotBeNullException)
case other ⇒ other
}
override def apply(t: Try[T]): Unit = {
setElem(t)
cb.invoke(this)
}
}
val NotYetThere = Failure(new Exception)
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class MapAsync[In, Out](parallelism: Int, f: In ⇒ Future[Out])
extends GraphStage[FlowShape[In, Out]] {
import MapAsync._
private val in = Inlet[In]("MapAsync.in")
private val out = Outlet[Out]("MapAsync.out")
override def initialAttributes = DefaultAttributes.mapAsync
override val shape = FlowShape(in, out)
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
new GraphStageLogic(shape) with InHandler with OutHandler {
override def toString = s"MapAsync.Logic(buffer=$buffer)"
//FIXME Put Supervision.stoppingDecider as a SupervisionStrategy on DefaultAttributes.mapAsync?
lazy val decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
var buffer: BufferImpl[Holder[Out]] = _
def holderCompleted(h: Holder[Out]): Unit = {
h.elem match {
case Failure(e) if decider(e) == Supervision.Stop ⇒ failStage(e)
case _ ⇒ if (isAvailable(out)) pushOne()
}
}
val futureCB = getAsyncCallback[Holder[Out]](holderCompleted)
private[this] def todo = buffer.used
override def preStart(): Unit = buffer = BufferImpl(parallelism, materializer)
@tailrec private def pushOne(): Unit =
if (buffer.isEmpty) {
if (isClosed(in)) completeStage()
else if (!hasBeenPulled(in)) pull(in)
} else if (buffer.peek().elem == NotYetThere) {
if (todo < parallelism && !hasBeenPulled(in)) tryPull(in)
} else buffer.dequeue().elem match {
case Success(elem) ⇒
push(out, elem)
if (todo < parallelism && !hasBeenPulled(in)) tryPull(in)
case Failure(ex) ⇒ pushOne()
}
override def onPush(): Unit = {
try {
val future = f(grab(in))
val holder = new Holder[Out](NotYetThere, futureCB)
buffer.enqueue(holder)
// #20217 We dispatch the future if it's ready to optimize away
// scheduling it to an execution context
future.value match {
case None ⇒ future.onComplete(holder)(akka.dispatch.ExecutionContexts.sameThreadExecutionContext)
case Some(v) ⇒
holder.setElem(v)
holderCompleted(holder)
}
} catch {
case NonFatal(ex) ⇒ if (decider(ex) == Supervision.Stop) failStage(ex)
}
if (todo < parallelism && !hasBeenPulled(in)) tryPull(in)
}
override def onUpstreamFinish(): Unit = if (todo == 0) completeStage()
override def onPull(): Unit = pushOne()
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class MapAsyncUnordered[In, Out](parallelism: Int, f: In ⇒ Future[Out])
extends GraphStage[FlowShape[In, Out]] {
private val in = Inlet[In]("MapAsyncUnordered.in")
private val out = Outlet[Out]("MapAsyncUnordered.out")
override def initialAttributes = DefaultAttributes.mapAsyncUnordered
override val shape = FlowShape(in, out)
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
new GraphStageLogic(shape) with InHandler with OutHandler {
override def toString = s"MapAsyncUnordered.Logic(inFlight=$inFlight, buffer=$buffer)"
val decider =
inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
private var inFlight = 0
private var buffer: BufferImpl[Out] = _
private[this] def todo = inFlight + buffer.used
override def preStart(): Unit = buffer = BufferImpl(parallelism, materializer)
def futureCompleted(result: Try[Out]): Unit = {
inFlight -= 1
result match {
case Success(elem) if elem != null ⇒
if (isAvailable(out)) {
if (!hasBeenPulled(in)) tryPull(in)
push(out, elem)
} else buffer.enqueue(elem)
case other ⇒
val ex = other match {
case Failure(t) ⇒ t
case Success(s) if s == null ⇒ ReactiveStreamsCompliance.elementMustNotBeNullException
}
if (decider(ex) == Supervision.Stop) failStage(ex)
else if (isClosed(in) && todo == 0) completeStage()
else if (!hasBeenPulled(in)) tryPull(in)
}
}
private val futureCB = getAsyncCallback(futureCompleted)
private val invokeFutureCB: Try[Out] ⇒ Unit = futureCB.invoke
override def onPush(): Unit = {
try {
val future = f(grab(in))
inFlight += 1
future.value match {
case None ⇒ future.onComplete(invokeFutureCB)(akka.dispatch.ExecutionContexts.sameThreadExecutionContext)
case Some(v) ⇒ futureCompleted(v)
}
} catch {
case NonFatal(ex) ⇒ if (decider(ex) == Supervision.Stop) failStage(ex)
}
if (todo < parallelism && !hasBeenPulled(in)) tryPull(in)
}
override def onUpstreamFinish(): Unit = {
if (todo == 0) completeStage()
}
override def onPull(): Unit = {
if (!buffer.isEmpty) push(out, buffer.dequeue())
else if (isClosed(in) && todo == 0) completeStage()
if (todo < parallelism && !hasBeenPulled(in)) tryPull(in)
}
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final case class Log[T](
name: String,
extract: T ⇒ Any,
logAdapter: Option[LoggingAdapter]) extends SimpleLinearGraphStage[T] {
override def toString = "Log"
// TODO more optimisations can be done here - prepare logOnPush function etc
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
new GraphStageLogic(shape) with OutHandler with InHandler {
import Log._
private var logLevels: LogLevels = _
private var log: LoggingAdapter = _
def decider = inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
override def preStart(): Unit = {
logLevels = inheritedAttributes.get[LogLevels](DefaultLogLevels)
log = logAdapter match {
case Some(l) ⇒ l
case _ ⇒
val mat = try ActorMaterializerHelper.downcast(materializer)
catch {
case ex: Exception ⇒
throw new RuntimeException("Log stage can only provide LoggingAdapter when used with ActorMaterializer! " +
"Provide a LoggingAdapter explicitly or use the actor based flow materializer.", ex)
}
Logging(mat.system, mat)(fromMaterializer)
}
}
override def onPush(): Unit = {
try {
val elem = grab(in)
if (isEnabled(logLevels.onElement))
log.log(logLevels.onElement, "[{}] Element: {}", name, extract(elem))
push(out, elem)
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case _ ⇒ pull(in)
}
}
}
override def onPull(): Unit = pull(in)
override def onUpstreamFailure(cause: Throwable): Unit = {
if (isEnabled(logLevels.onFailure))
logLevels.onFailure match {
case Logging.ErrorLevel ⇒ log.error(cause, "[{}] Upstream failed.", name)
case level ⇒ log.log(level, "[{}] Upstream failed, cause: {}: {}", name, Logging.simpleName(cause.getClass), cause.getMessage)
}
super.onUpstreamFailure(cause)
}
override def onUpstreamFinish(): Unit = {
if (isEnabled(logLevels.onFinish))
log.log(logLevels.onFinish, "[{}] Upstream finished.", name)
super.onUpstreamFinish()
}
override def onDownstreamFinish(): Unit = {
if (isEnabled(logLevels.onFinish))
log.log(logLevels.onFinish, "[{}] Downstream finished.", name)
super.onDownstreamFinish()
}
private def isEnabled(l: LogLevel): Boolean = l.asInt != OffInt
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] object Log {
/**
* Must be located here to be visible for implicit resolution, when [[Materializer]] is passed to [[Logging]]
* More specific LogSource than `fromString`, which would add the ActorSystem name in addition to the supervision to the log source.
*/
final val fromMaterializer = new LogSource[Materializer] {
// do not expose private context classes (of OneBoundedInterpreter)
override def getClazz(t: Materializer): Class[_] = classOf[Materializer]
override def genString(t: Materializer): String = {
try s"$DefaultLoggerName(${ActorMaterializerHelper.downcast(t).supervisor.path})"
catch {
case ex: Exception ⇒ LogSource.fromString.genString(DefaultLoggerName)
}
}
}
private final val DefaultLoggerName = "akka.stream.Log"
private final val OffInt = LogLevels.Off.asInt
private final val DefaultLogLevels = LogLevels(onElement = Logging.DebugLevel, onFinish = Logging.DebugLevel, onFailure = Logging.ErrorLevel)
}
/**
* INTERNAL API
*/
@InternalApi private[stream] object TimerKeys {
case object TakeWithinTimerKey
case object DropWithinTimerKey
case object GroupedWithinTimerKey
}
@InternalApi private[akka] object GroupedWeightedWithin {
val groupedWeightedWithinTimer = "GroupedWeightedWithinTimer"
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final class GroupedWeightedWithin[T](val maxWeight: Long, costFn: T ⇒ Long, val interval: FiniteDuration) extends GraphStage[FlowShape[T, immutable.Seq[T]]] {
require(maxWeight > 0, "maxWeight must be greater than 0")
require(interval > Duration.Zero)
val in = Inlet[T]("in")
val out = Outlet[immutable.Seq[T]]("out")
override def initialAttributes = DefaultAttributes.groupedWeightedWithin
val shape = FlowShape(in, out)
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new TimerGraphStageLogic(shape) with InHandler with OutHandler {
private val buf: VectorBuilder[T] = new VectorBuilder
private var pending: T = null.asInstanceOf[T]
private var pendingWeight: Long = 0L
// True if:
// - buf is nonEmpty
// AND
// - (timer fired
// OR
// totalWeight >= maxWeight
// OR
// pending != null
// OR
// upstream completed)
private var pushEagerly = false
private var groupEmitted = true
private var finished = false
private var totalWeight = 0L
private var hasElements = false
override def preStart() = {
schedulePeriodically(GroupedWeightedWithin.groupedWeightedWithinTimer, interval)
pull(in)
}
private def nextElement(elem: T): Unit = {
groupEmitted = false
val cost = costFn(elem)
if (cost < 0L) failStage(new IllegalArgumentException(s"Negative weight [$cost] for element [$elem] is not allowed"))
else {
hasElements = true
if (totalWeight + cost <= maxWeight) {
buf += elem
totalWeight += cost
if (totalWeight < maxWeight) pull(in)
else {
// `totalWeight >= maxWeight` which means that downstream can get the next group.
if (!isAvailable(out)) {
// We should emit group when downstream becomes available
pushEagerly = true
// we want to pull anyway, since we allow for zero weight elements
// but since `emitGroup()` will pull internally (by calling `startNewGroup()`)
// we also have to pull if downstream hasn't yet requested an element.
pull(in)
} else {
schedulePeriodically(GroupedWeightedWithin.groupedWeightedWithinTimer, interval)
emitGroup()
}
}
} else {
//we have a single heavy element that weighs more than the limit
if (totalWeight == 0L) {
buf += elem
totalWeight += cost
pushEagerly = true
} else {
pending = elem
pendingWeight = cost
}
schedulePeriodically(GroupedWeightedWithin.groupedWeightedWithinTimer, interval)
tryCloseGroup()
}
}
}
private def tryCloseGroup(): Unit = {
if (isAvailable(out)) emitGroup()
else if (pending != null || finished) pushEagerly = true
}
private def emitGroup(): Unit = {
groupEmitted = true
push(out, buf.result())
buf.clear()
if (!finished) startNewGroup()
else if (pending != null) emit(out, Vector(pending), () ⇒ completeStage())
else completeStage()
}
private def startNewGroup(): Unit = {
if (pending != null) {
totalWeight = pendingWeight
pendingWeight = 0L
buf += pending
pending = null.asInstanceOf[T]
groupEmitted = false
} else {
totalWeight = 0L
hasElements = false
}
pushEagerly = false
if (isAvailable(in)) nextElement(grab(in))
else if (!hasBeenPulled(in)) pull(in)
}
override def onPush(): Unit = {
if (pending == null) nextElement(grab(in)) // otherwise keep the element for next round
}
override def onPull(): Unit = if (pushEagerly) emitGroup()
override def onUpstreamFinish(): Unit = {
finished = true
if (groupEmitted) completeStage()
else tryCloseGroup()
}
override protected def onTimer(timerKey: Any) = if (hasElements) {
if (isAvailable(out)) emitGroup()
else pushEagerly = true
}
setHandlers(in, out, this)
}
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final class Delay[T](val d: FiniteDuration, val strategy: DelayOverflowStrategy) extends SimpleLinearGraphStage[T] {
private[this] def timerName = "DelayedTimer"
final val DelayPrecisionMS = 10
override def initialAttributes: Attributes = DefaultAttributes.delay
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new TimerGraphStageLogic(shape) with InHandler with OutHandler {
val size =
inheritedAttributes.get[InputBuffer] match {
case None ⇒ throw new IllegalStateException(s"Couldn't find InputBuffer Attribute for $this")
case Some(InputBuffer(min, max)) ⇒ max
}
val delayMillis = d.toMillis
var buffer: BufferImpl[(Long, T)] = _ // buffer has pairs timestamp with upstream element
override def preStart(): Unit = buffer = BufferImpl(size, materializer)
val onPushWhenBufferFull: () ⇒ Unit = strategy match {
case EmitEarly ⇒
() ⇒ {
if (!isTimerActive(timerName))
push(out, buffer.dequeue()._2)
else {
cancelTimer(timerName)
onTimer(timerName)
}
}
case DropHead ⇒
() ⇒ {
buffer.dropHead()
grabAndPull()
}
case DropTail ⇒
() ⇒ {
buffer.dropTail()
grabAndPull()
}
case DropNew ⇒
() ⇒ {
grab(in)
if (!isTimerActive(timerName)) scheduleOnce(timerName, d)
}
case DropBuffer ⇒
() ⇒ {
buffer.clear()
grabAndPull()
}
case Fail ⇒
() ⇒ {
failStage(new BufferOverflowException(s"Buffer overflow for delay combinator (max capacity was: $size)!"))
}
case Backpressure ⇒
() ⇒ {
throw new IllegalStateException("Delay buffer must never overflow in Backpressure mode")
}
}
def onPush(): Unit = {
if (buffer.isFull)
onPushWhenBufferFull()
else {
grabAndPull()
if (!isTimerActive(timerName)) {
scheduleOnce(timerName, d)
}
}
}
def pullCondition: Boolean =
strategy != Backpressure || buffer.used < size
def grabAndPull(): Unit = {
buffer.enqueue((System.nanoTime(), grab(in)))
if (pullCondition) pull(in)
}
override def onUpstreamFinish(): Unit =
completeIfReady()
def onPull(): Unit = {
if (!isTimerActive(timerName) && !buffer.isEmpty) {
val waitTime = nextElementWaitTime()
if (waitTime < 0) {
push(out, buffer.dequeue()._2)
} else {
scheduleOnce(timerName, Math.max(DelayPrecisionMS, waitTime).millis)
}
}
if (!isClosed(in) && !hasBeenPulled(in) && pullCondition)
pull(in)
completeIfReady()
}
setHandler(in, this)
setHandler(out, this)
def completeIfReady(): Unit = if (isClosed(in) && buffer.isEmpty) completeStage()
def nextElementWaitTime(): Long = {
delayMillis - NANOSECONDS.toMillis(System.nanoTime() - buffer.peek()._1)
}
final override protected def onTimer(key: Any): Unit = {
if (isAvailable(out))
push(out, buffer.dequeue()._2)
if (!buffer.isEmpty) {
val waitTime = nextElementWaitTime()
if (waitTime > DelayPrecisionMS)
scheduleOnce(timerName, waitTime.millis)
}
completeIfReady()
}
}
override def toString = "Delay"
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final class TakeWithin[T](val timeout: FiniteDuration) extends SimpleLinearGraphStage[T] {
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)
setHandlers(in, out, this)
final override protected def onTimer(key: Any): Unit = completeStage()
override def preStart(): Unit = scheduleOnce("TakeWithinTimer", timeout)
}
override def toString = "TakeWithin"
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final class DropWithin[T](val timeout: FiniteDuration) extends SimpleLinearGraphStage[T] {
override def createLogic(inheritedAttributes: Attributes): GraphStageLogic = new GraphStageLogic(shape) with InHandler with OutHandler {
private val startNanoTime = System.nanoTime()
private val timeoutInNano = timeout.toNanos
def onPush(): Unit = {
if (System.nanoTime() - startNanoTime <= timeoutInNano) {
pull(in)
} else {
push(out, grab(in))
// change the in handler to avoid System.nanoTime call after timeout
setHandler(in, new InHandler {
def onPush() = push(out, grab(in))
})
}
}
def onPull(): Unit = pull(in)
setHandlers(in, out, this)
}
override def toString = "DropWithin"
}
/**
* INTERNAL API
*/
@InternalApi private[akka] 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 toString = s"Reduce.Logic(aggregator=$aggregator)"
var aggregator: T = _
private def decider =
inheritedAttributes.get[SupervisionStrategy].map(_.decider).getOrElse(Supervision.stoppingDecider)
def setInitialInHandler(): Unit = {
// Initial input handler
setHandler(in, new InHandler {
override def onPush(): Unit = {
aggregator = grab(in)
pull(in)
setHandler(in, self)
}
override def onUpstreamFinish(): Unit =
failStage(new NoSuchElementException("reduce over empty stream"))
})
}
override def onPush(): Unit = {
val elem = grab(in)
try {
aggregator = f(aggregator, elem)
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case Supervision.Restart ⇒
aggregator = _: T
setInitialInHandler()
case _ ⇒ ()
}
} finally {
if (!isClosed(in)) pull(in)
}
}
override def onPull(): Unit = pull(in)
override def onUpstreamFinish(): Unit = {
push(out, aggregator)
completeStage()
}
setInitialInHandler()
setHandler(out, self)
}
override def toString = "Reduce"
}
/**
* INTERNAL API
*/
@InternalApi private[stream] object RecoverWith
@InternalApi private[akka] final class RecoverWith[T, M](val maximumRetries: Int, val pf: PartialFunction[Throwable, Graph[SourceShape[T], M]]) extends SimpleLinearGraphStage[T] {
override def initialAttributes = DefaultAttributes.recoverWith
override def createLogic(attr: Attributes) = new GraphStageLogic(shape) {
var attempt = 0
setHandler(in, new InHandler {
override def onPush(): Unit = push(out, grab(in))
override def onUpstreamFailure(ex: Throwable) = onFailure(ex)
})
setHandler(out, new OutHandler {
override def onPull(): Unit = pull(in)
})
def onFailure(ex: Throwable) =
if ((maximumRetries < 0 || attempt < maximumRetries) && pf.isDefinedAt(ex)) {
switchTo(pf(ex))
attempt += 1
} else
failStage(ex)
def switchTo(source: Graph[SourceShape[T], M]): Unit = {
val sinkIn = new SubSinkInlet[T]("RecoverWithSink")
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()
}
Source.fromGraph(source).runWith(sinkIn.sink)(interpreter.subFusingMaterializer)
setHandler(out, outHandler)
if (isAvailable(out)) sinkIn.pull()
}
}
override def toString: String = "RecoverWith"
}
/**
* INTERNAL API
*/
@InternalApi private[akka] final class StatefulMapConcat[In, Out](val f: () ⇒ In ⇒ immutable.Iterable[Out]) extends GraphStage[FlowShape[In, Out]] {
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 =
if (hasNext) {
push(out, currentIterator.next())
if (!hasNext && isClosed(in)) completeStage()
} else if (!isClosed(in))
pull(in)
else completeStage()
def onFinish(): Unit = if (!hasNext) completeStage()
override def onPush(): Unit =
try {
currentIterator = plainFun(grab(in)).iterator
pushPull()
} catch {
case NonFatal(ex) ⇒ decider(ex) match {
case Supervision.Stop ⇒ failStage(ex)
case Supervision.Resume ⇒ if (!hasBeenPulled(in)) pull(in)
case Supervision.Restart ⇒
restartState()
if (!hasBeenPulled(in)) pull(in)
}
}
override def onUpstreamFinish(): Unit = onFinish()
override def onPull(): Unit = pushPull()
private def restartState(): Unit = {
plainFun = f()
currentIterator = null
}
}
override def toString = "StatefulMapConcat"
}
