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+str #18620 add Source.blocking() for legacy API integration

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This commit is contained in:
Alexander Golubev 2016-02-22 23:22:47 -05:00
parent 1596ae7f13
commit 69e6052cbe
12 changed files with 726 additions and 11 deletions
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58
akka-stream/src/main/scala/akka/stream/javadsl/Source.scala
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@ -10,7 +10,7 @@ import akka.actor.{ ActorRef, Cancellable, Props }
import akka.event.LoggingAdapter
import akka.japi.{ Pair, Util, function }
import akka.stream._
import akka.stream.impl.{ ConstantFun, StreamLayout }
import akka.stream.impl.{ ConstantFun, StreamLayout, SourceQueueAdapter }
import akka.stream.stage.Stage
import org.reactivestreams.{ Publisher, Subscriber }
import scala.annotation.unchecked.uncheckedVariance
@ -307,6 +307,62 @@ object Source {
def queue[T](bufferSize: Int, overflowStrategy: OverflowStrategy): Source[T, SourceQueueWithComplete[T]] =
new Source(scaladsl.Source.queue[T](bufferSize, overflowStrategy).mapMaterializedValue(new SourceQueueAdapter(_)))
/**
* Start a new `Source` from some resource which can be opened, read and closed.
* Interaction with resource happens in a blocking way.
*
* Example:
* {{{
* Source.unfoldResource(
* () -> new BufferedReader(new FileReader("...")),
* reader -> reader.readLine(),
* reader -> reader.close())
* }}}
*
* You can use the supervision strategy to handle exceptions for `read` function. All exceptions thrown by `create`
* or `close` will fail the stream.
*
* `Restart` supervision strategy will close and create blocking IO again. Default strategy is `Stop` which means
* that stream will be terminated on error in `read` function by default.
*
* You can configure the default dispatcher for this Source by changing the `akka.stream.blocking-io-dispatcher` or
* set it for a given Source by using [[ActorAttributes]].
*
* @param create - function that is called on stream start and creates/opens resource.
* @param read - function that reads data from opened resource. It is called each time backpressure signal
* is received. Stream calls close and completes when `read` returns None.
* @param close - function that closes resource
*/
def unfoldResource[T, S](create: function.Creator[S],
read: function.Function[S, Optional[T]],
close: function.Procedure[S]): javadsl.Source[T, NotUsed] =
new Source(scaladsl.Source.unfoldResource[T,S](create.create,
(s: S) ⇒ read.apply(s).asScala, close.apply))
/**
* Start a new `Source` from some resource which can be opened, read and closed.
* It's similar to `unfoldResource` but takes functions that return `CopletionStage` instead of plain values.
*
* You can use the supervision strategy to handle exceptions for `read` function or failures of produced `Futures`.
* All exceptions thrown by `create` or `close` as well as fails of returned futures will fail the stream.
*
* `Restart` supervision strategy will close and create resource. Default strategy is `Stop` which means
* that stream will be terminated on error in `read` function (or future) by default.
*
* You can configure the default dispatcher for this Source by changing the `akka.stream.blocking-io-dispatcher` or
* set it for a given Source by using [[ActorAttributes]].
*
* @param create - function that is called on stream start and creates/opens resource.
* @param read - function that reads data from opened resource. It is called each time backpressure signal
* is received. Stream calls close and completes when `CompletionStage` from read function returns None.
* @param close - function that closes resource
*/
def unfoldResourceAsync[T, S](create: function.Creator[CompletionStage[S]],
read: function.Function[S, CompletionStage[Optional[T]]],
close: function.Function[S, CompletionStage[Done]]): javadsl.Source[T, NotUsed] =
new Source(scaladsl.Source.unfoldResourceAsync[T,S](() ⇒ create.create().toScala,
(s: S) ⇒ read.apply(s).toScala.map(_.asScala)(akka.dispatch.ExecutionContexts.sameThreadExecutionContext),
(s: S) ⇒ close.apply(s).toScala))
}
/**