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#22808 Move CoupledTerminationFlow to Flow.fromSinkAndSourceCoupled

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Also mention coupled variant in the uncoupled scaladoc
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Martynas Mickevičius 2017-05-09 13:55:08 +03:00 • committed by Konrad `ktoso` Malawski
parent f2adb0a3fd
commit c840bd6f37
7 changed files with 199 additions and 34 deletions
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80
akka-stream/src/main/scala/akka/stream/scaladsl/Flow.scala
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@ -315,6 +315,11 @@ object Flow {
/**
* Creates a `Flow` from a `Sink` and a `Source` where the Flow's input
* will be sent to the Sink and the Flow's output will come from the Source.
*
* The completion of the Sink and Source sides of a Flow constructed using
* this method are independent. So if the Sink receives a completion signal,
* the Source side will remain unaware of that. If you are looking to couple
* the termination signals of the two sides use `Flow.fromSinkAndSourceCoupled` instead.
*/
def fromSinkAndSource[I, O](sink: Graph[SinkShape[I], _], source: Graph[SourceShape[O], _]): Flow[I, O, NotUsed] =
fromSinkAndSourceMat(sink, source)(Keep.none)
@ -323,11 +328,86 @@ object Flow {
* Creates a `Flow` from a `Sink` and a `Source` where the Flow's input
* will be sent to the Sink and the Flow's output will come from the Source.
*
* The completion of the Sink and Source sides of a Flow constructed using
* this method are independent. So if the Sink receives a completion signal,
* the Source side will remain unaware of that. If you are looking to couple
* the termination signals of the two sides use `Flow.fromSinkAndSourceCoupledMat` instead.
*
* The `combine` function is used to compose the materialized values of the `sink` and `source`
* into the materialized value of the resulting [[Flow]].
*/
def fromSinkAndSourceMat[I, O, M1, M2, M](sink: Graph[SinkShape[I], M1], source: Graph[SourceShape[O], M2])(combine: (M1, M2) ⇒ M): Flow[I, O, M] =
fromGraph(GraphDSL.create(sink, source)(combine) { implicit b ⇒ (in, out) ⇒ FlowShape(in.in, out.out) })
/**
* Allows coupling termination (cancellation, completion, erroring) of Sinks and Sources while creating a Flow from them.
* Similar to [[Flow.fromSinkAndSource]] however couples the termination of these two stages.
*
* E.g. if the emitted [[Flow]] gets a cancellation, the [[Source]] of course is cancelled,
* however the Sink will also be completed. The table below illustrates the effects in detail:
*
* <table>
* <tr>
* <th>Returned Flow</th>
* <th>Sink (<code>in</code>)</th>
* <th>Source (<code>out</code>)</th>
* </tr>
* <tr>
* <td><i>cause:</i> upstream (sink-side) receives completion</td>
* <td><i>effect:</i> receives completion</td>
* <td><i>effect:</i> receives cancel</td>
* </tr>
* <tr>
* <td><i>cause:</i> upstream (sink-side) receives error</td>
* <td><i>effect:</i> receives error</td>
* <td><i>effect:</i> receives cancel</td>
* </tr>
* <tr>
* <td><i>cause:</i> downstream (source-side) receives cancel</td>
* <td><i>effect:</i> completes</td>
* <td><i>effect:</i> receives cancel</td>
* </tr>
* <tr>
* <td><i>effect:</i> cancels upstream, completes downstream</td>
* <td><i>effect:</i> completes</td>
* <td><i>cause:</i> signals complete</td>
* </tr>
* <tr>
* <td><i>effect:</i> cancels upstream, errors downstream</td>
* <td><i>effect:</i> receives error</td>
* <td><i>cause:</i> signals error or throws</td>
* </tr>
* <tr>
* <td><i>effect:</i> cancels upstream, completes downstream</td>
* <td><i>cause:</i> cancels</td>
* <td><i>effect:</i> receives cancel</td>
* </tr>
* </table>
*
*/
def fromSinkAndSourceCoupled[I, O](sink: Graph[SinkShape[I], _], source: Graph[SourceShape[O], _]): Flow[I, O, NotUsed] =
fromSinkAndSourceCoupledMat(sink, source)(Keep.none)
/**
* Allows coupling termination (cancellation, completion, erroring) of Sinks and Sources while creating a Flow from them.
* Similar to [[Flow.fromSinkAndSource]] however couples the termination of these two stages.
*
* E.g. if the emitted [[Flow]] gets a cancellation, the [[Source]] of course is cancelled,
* however the Sink will also be completed. The table on [[Flow.fromSinkAndSourceCoupled]]
* illustrates the effects in detail.
*
* The `combine` function is used to compose the materialized values of the `sink` and `source`
* into the materialized value of the resulting [[Flow]].
*/
def fromSinkAndSourceCoupledMat[I, O, M1, M2, M](sink: Graph[SinkShape[I], M1], source: Graph[SourceShape[O], M2])(combine: (M1, M2) ⇒ M): Flow[I, O, M] =
// format: OFF
Flow.fromGraph(GraphDSL.create(sink, source)(combine) { implicit b => (i, o) =>
import GraphDSL.Implicits._
val bidi = b.add(new CoupledTerminationBidi[I, O])
/* bidi.in1 ~> */ bidi.out1 ~> i; o ~> bidi.in2 /* ~> bidi.out2 */
FlowShape(bidi.in1, bidi.out2)
})
// format: ON
}
object RunnableGraph {