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Re-write InputStreamSource as GraphStage (#26811)

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* Re-write InputStreamPublisher as a GraphStage
* Deprecate IOResult.failure and introduce IOOperationIncompleteException

After some dicussion with @johanandren, @raboof and @2m about the
confusion of the materialised value of the IO streams to complete
even if there is an exception (with the exception in the IOResult)
this now changes it to:

* Deprecate failure in IOResult so it is always set to Success(Done)
* Stop using AbrubtIOTerminationException as the inner IOResult also
contains an exception causing confusion
This commit is contained in:
Christopher Batey 2019-07-02 10:46:16 +01:00 • committed by GitHub
parent cfed2512d7
commit 200b07e534
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11 changed files with 252 additions and 177 deletions
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46
akka-stream/src/main/scala/akka/stream/impl/io/IOSources.scala
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@ -4,21 +4,15 @@
package akka.stream.impl.io
import java.io.InputStream
import java.nio.ByteBuffer
import java.nio.channels.{ CompletionHandler, FileChannel }
import java.nio.file.{ Files, NoSuchFileException, Path, StandardOpenOption }
import akka.Done
import akka.annotation.InternalApi
import akka.stream.ActorAttributes.Dispatcher
import akka.stream.Attributes.InputBuffer
import akka.stream.impl.{ ErrorPublisher, SourceModule }
import akka.stream.stage._
import akka.stream.{ IOResult, _ }
import akka.util.ByteString
import com.github.ghik.silencer.silent
import org.reactivestreams.Publisher
import scala.annotation.tailrec
import scala.concurrent.{ Future, Promise }
@ -140,43 +134,3 @@ private[akka] final class FileSource(path: Path, chunkSize: Int, startPosition:
override def toString = s"FileSource($path, $chunkSize)"
}
/**
* INTERNAL API
* Source backed by the given input stream.
*/
@InternalApi private[akka] final class InputStreamSource(
createInputStream: () => InputStream,
chunkSize: Int,
val attributes: Attributes,
shape: SourceShape[ByteString])
extends SourceModule[ByteString, Future[IOResult]](shape) {
override def create(context: MaterializationContext) = {
val materializer = ActorMaterializerHelper.downcast(context.materializer)
val ioResultPromise = Promise[IOResult]()
@silent
val pub = try {
val is = createInputStream() // can throw, i.e. FileNotFound
val props = InputStreamPublisher
.props(is, ioResultPromise, chunkSize)
.withDispatcher(context.effectiveAttributes.mandatoryAttribute[Dispatcher].dispatcher)
val ref = materializer.actorOf(context, props)
akka.stream.actor.ActorPublisher[ByteString](ref)
} catch {
case ex: Exception =>
ioResultPromise.failure(ex)
ErrorPublisher(ex, attributes.nameOrDefault("inputStreamSource")).asInstanceOf[Publisher[ByteString]]
}
(pub, ioResultPromise.future)
}
override protected def newInstance(shape: SourceShape[ByteString]): SourceModule[ByteString, Future[IOResult]] =
new InputStreamSource(createInputStream, chunkSize, attributes, shape)
override def withAttributes(attr: Attributes): SourceModule[ByteString, Future[IOResult]] =
new InputStreamSource(createInputStream, chunkSize, attr, amendShape(attr))
}