Package akka.stream.scaladsl

Class FlowWithContext<In,​CtxIn,​Out,​CtxOut,​Mat>

  • All Implemented Interfaces:
    Graph<FlowShape<scala.Tuple2<In,​CtxIn>,​scala.Tuple2<Out,​CtxOut>>,​Mat>, FlowWithContextOps<Out,​CtxOut,​Mat>
    public final class FlowWithContext<In,​CtxIn,​Out,​CtxOut,​Mat>
extends akka.stream.GraphDelegate<FlowShape<scala.Tuple2<In,​CtxIn>,​scala.Tuple2<Out,​CtxOut>>,​Mat>
implements FlowWithContextOps<Out,​CtxOut,​Mat>
    A flow that provides operations which automatically propagate the context of an element. Only a subset of common operations from FlowOps is supported. As an escape hatch you can use FlowWithContextOps.via to manually provide the context propagation for otherwise unsupported operations.

    An "empty" flow can be created by calling FlowWithContext[Ctx, T].

    • Constructor Detail

      • FlowWithContext

        public FlowWithContext​(Flow<scala.Tuple2<In,​CtxIn>,​scala.Tuple2<Out,​CtxOut>,​Mat> delegate)

    • Method Detail

      • apply

        public static <In,​Ctx> FlowWithContext<In,​Ctx,​In,​Ctx,​NotUsed> apply()
        Creates an "empty" FlowWithContext that passes elements through with their context unchanged.

      • fromTuples

        public static <In,​CtxIn,​Out,​CtxOut,​Mat> FlowWithContext<In,​CtxIn,​Out,​CtxOut,​Mat> fromTuples​(Flow<scala.Tuple2<In,​CtxIn>,​scala.Tuple2<Out,​CtxOut>,​Mat> flow)
        Creates a FlowWithContext from a regular flow that operates on a tuple of (data, context) elements.

      • via

        public <Out2,​Ctx2,​Mat2> FlowWithContext<In,​CtxIn,​Out2,​Ctx2,​Mat> via​(Graph<FlowShape<scala.Tuple2<Out,​CtxOut>,​scala.Tuple2<Out2,​Ctx2>>,​Mat2> viaFlow)
        Description copied from interface: FlowWithContextOps
        Transform this flow by the regular flow. The given flow must support manual context propagation by taking and producing tuples of (data, context).

        It is up to the implementer to ensure the inner flow does not exhibit any behaviour that is not expected by the downstream elements, such as reordering. For more background on these requirements see https://doc.akka.io/libraries/akka-core/current/stream/stream-context.html.

        This can be used as an escape hatch for operations that are not (yet) provided with automatic context propagation here.

        Specified by:
        via in interface FlowWithContextOps<In,​CtxIn,​Out>
        See Also:
        akka.stream.scaladsl.FlowOps.via

      • unsafeDataVia

        public <Out2,​Mat2> FlowWithContext<In,​CtxIn,​Out2,​CtxOut,​Mat> unsafeDataVia​(Graph<FlowShape<Out,​Out2>,​Mat2> viaFlow)
        Description copied from interface: FlowWithContextOps
        Transform this flow by the regular flow. The given flow works on the data portion of the stream and ignores the context.

        The given flow *must* not re-order, drop or emit multiple elements for one incoming element, the sequence of incoming contexts is re-combined with the outgoing elements of the stream. If a flow not fulfilling this requirement is used the stream will not fail but continue running in a corrupt state and re-combine incorrect pairs of elements and contexts or deadlock.

        For more background on these requirements see https://doc.akka.io/libraries/akka-core/current/stream/stream-context.html.

        Specified by:
        unsafeDataVia in interface FlowWithContextOps<In,​CtxIn,​Out>

      • viaMat

        public <Out2,​Ctx2,​Mat2,​Mat3> FlowWithContext<In,​CtxIn,​Out2,​Ctx2,​Mat3> viaMat​(Graph<FlowShape<scala.Tuple2<Out,​CtxOut>,​scala.Tuple2<Out2,​Ctx2>>,​Mat2> flow,
                                                                                                                       scala.Function2<Mat,​Mat2,​Mat3> combine)
        Description copied from interface: FlowWithContextOps
        Transform this flow by the regular flow. The given flow must support manual context propagation by taking and producing tuples of (data, context).

        It is up to the implementer to ensure the inner flow does not exhibit any behaviour that is not expected by the downstream elements, such as reordering. For more background on these requirements see https://doc.akka.io/libraries/akka-core/current/stream/stream-context.html.

        This can be used as an escape hatch for operations that are not (yet) provided with automatic context propagation here.

        The combine function is used to compose the materialized values of this flow and that flow into the materialized value of the resulting Flow.

        Specified by:
        viaMat in interface FlowWithContextOps<In,​CtxIn,​Out>
        See Also:
        akka.stream.scaladsl.FlowOpsMat.viaMat

      • mapMaterializedValue

        public <Mat2> FlowWithContext<In,​CtxIn,​Out,​CtxOut,​Mat2> mapMaterializedValue​(scala.Function1<Mat,​Mat2> f)
        Context-preserving variant of akka.stream.scaladsl.Flow.mapMaterializedValue.

        See Also:
        akka.stream.scaladsl.Flow.mapMaterializedValue

      • asJava

        public <JIn extends In,​JCtxIn extends CtxIn,​JOut,​JCtxOut,​JMat> FlowWithContext<JIn,​JCtxIn,​JOut,​JCtxOut,​JMat> asJava()