Package org.apache.pekko.stream.javadsl

Class SourceWithContext<Out,​Ctx,​Mat>

    • Method Detail

      • fromPairs

        public static <Out,​CtxOut,​Mat> SourceWithContext<Out,​CtxOut,​Mat> fromPairs​(Source<Pair<Out,​CtxOut>,​Mat> under)
        Creates a SourceWithContext from a regular flow that operates on Pair elements.

      • unsafeOptionalDataVia

        public static <SOut,​FOut,​Ctx,​SMat,​FMat,​Mat> SourceWithContext<java.util.Optional<FOut>,​Ctx,​Mat> unsafeOptionalDataVia​(SourceWithContext<java.util.Optional<SOut>,​Ctx,​SMat> source,
                                                                                                                                                                Flow<SOut,​FOut,​FMat> viaFlow,
                                                                                                                                                                Function2<SMat,​FMat,​Mat> combine)
        Creates a SourceWithContext from an existing base SourceWithContext outputting an optional element and applying an additional viaFlow only if the element in the stream is defined.

        '''Emits when''' the provided viaFlow runs with defined elements

        '''Backpressures when''' the viaFlow runs for the defined elements and downstream backpressures

        '''Completes when''' upstream completes

        '''Cancels when''' downstream cancels

        Parameters:
        source - The base source that outputs an optional element
        viaFlow - The flow that gets used if the optional element in is defined. This flow only works on the data portion of flow and ignores the context so this flow *must* not re-order, drop or emit multiple elements for one incoming element
        combine - How to combine the materialized values of source and viaFlow
        Returns:
        a SourceWithContext with the viaFlow applied onto defined elements of the flow. The output value is contained within an Optional which indicates whether the original source's element had viaFlow applied.
        Since:
        1.1.0

      • via

        public <Out2,​Ctx2,​Mat2> SourceWithContext<Out2,​Ctx2,​Mat> via​(Graph<FlowShape<Pair<Out,​Ctx>,​Pair<Out2,​Ctx2>>,​Mat2> viaFlow)
        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 behavior that is not expected by the downstream elements, such as reordering. For more background on these requirements see https://pekko.apache.org/docs/pekko/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.

        See Also:
        pekko.stream.javadsl.Flow.via

      • unsafeDataVia

        public <Out2,​Mat2> SourceWithContext<Out2,​Ctx,​Mat> unsafeDataVia​(Graph<FlowShape<Out,​Out2>,​Mat2> viaFlow)
        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://pekko.apache.org/docs/pekko/current/stream/stream-context.html.

      • withAttributes

        public SourceWithContext<Out,​Ctx,​Mat> withAttributes​(Attributes attr)
        Context-preserving variant of pekko.stream.javadsl.Source.withAttributes.

        See Also:
        pekko.stream.javadsl.Source.withAttributes

      • mapError

        public SourceWithContext<Out,​Ctx,​Mat> mapError​(scala.PartialFunction<java.lang.Throwable,​java.lang.Throwable> pf)
        Context-preserving variant of pekko.stream.javadsl.Source.mapError.

        See Also:
        pekko.stream.javadsl.Source.mapError

      • mapMaterializedValue

        public <Mat2> SourceWithContext<Out,​Ctx,​Mat2> mapMaterializedValue​(Function<Mat,​Mat2> f)
        Context-preserving variant of pekko.stream.javadsl.Source.mapMaterializedValue.

        See Also:
        pekko.stream.javadsl.Flow.mapMaterializedValue

      • asSource

        public Source<Pair<Out,​Ctx>,​Mat> asSource()
        Stops automatic context propagation from here and converts this to a regular stream of a pair of (data, context).

      • collect

        public <Out2> SourceWithContext<Out2,​Ctx,​Mat> collect​(scala.PartialFunction<Out,​Out2> pf)
        Context-preserving variant of pekko.stream.javadsl.Source.collect.

        Note, that the context of elements that are filtered out is skipped as well.

        See Also:
        pekko.stream.javadsl.Source.collect

      • filter

        public SourceWithContext<Out,​Ctx,​Mat> filter​(Predicate<Out> p)
        Context-preserving variant of pekko.stream.javadsl.Source.filter.

        Note, that the context of elements that are filtered out is skipped as well.

        See Also:
        pekko.stream.javadsl.Source.filter

      • filterNot

        public SourceWithContext<Out,​Ctx,​Mat> filterNot​(Predicate<Out> p)
        Context-preserving variant of pekko.stream.javadsl.Source.filterNot.

        Note, that the context of elements that are filtered out is skipped as well.

        See Also:
        pekko.stream.javadsl.Source.filterNot

      • grouped

        public SourceWithContext<java.util.List<Out>,​java.util.List<Ctx>,​Mat> grouped​(int n)
        Context-preserving variant of pekko.stream.javadsl.Source.grouped.

        Each output group will be associated with a Seq of corresponding context elements.

        See Also:
        pekko.stream.javadsl.Source.grouped

      • map

        public <Out2> SourceWithContext<Out2,​Ctx,​Mat> map​(Function<Out,​Out2> f)
        Context-preserving variant of pekko.stream.javadsl.Source.map.

        See Also:
        pekko.stream.javadsl.Source.map

      • mapAsync

        public <Out2> SourceWithContext<Out2,​Ctx,​Mat> mapAsync​(int parallelism,
                                                                   Function<Out,​java.util.concurrent.CompletionStage<Out2>> f)
        Context-preserving variant of pekko.stream.javadsl.Source.mapAsync.

        See Also:
        pekko.stream.javadsl.Source.mapAsync

      • mapAsyncPartitioned

        public <Out2,​P> SourceWithContext<Out2,​Ctx,​Mat> mapAsyncPartitioned​(int parallelism,
                                                                                      Function<Out,​P> partitioner,
                                                                                      Function2<Out,​P,​java.util.concurrent.CompletionStage<Out2>> f)
        Context-preserving variant of pekko.stream.javadsl.Source.mapAsyncPartitioned.

        Since:
        1.1.0
        See Also:
        pekko.stream.javadsl.Source.mapAsyncPartitioned

      • mapAsyncPartitionedUnordered

        public <Out2,​P> SourceWithContext<Out2,​Ctx,​Mat> mapAsyncPartitionedUnordered​(int parallelism,
                                                                                               Function<Out,​P> partitioner,
                                                                                               Function2<Out,​P,​java.util.concurrent.CompletionStage<Out2>> f)
        Context-preserving variant of pekko.stream.javadsl.Source.mapAsyncPartitionedUnordered.

        Since:
        1.1.0
        See Also:
        pekko.stream.javadsl.Source.mapAsyncPartitionedUnordered

      • mapConcat

        public <Out2> SourceWithContext<Out2,​Ctx,​Mat> mapConcat​(Function<Out,​? extends java.lang.Iterable<Out2>> f)
        Context-preserving variant of pekko.stream.javadsl.Source.mapConcat.

        The context of the input element will be associated with each of the output elements calculated from this input element.

        Example:

        def dup(element: String) = Seq(element, element)

        Input:

        ("a", 1) ("b", 2)

        inputElements.mapConcat(dup)

        Output:

        ("a", 1) ("a", 1) ("b", 2) ("b", 2)

        See Also:
        pekko.stream.javadsl.Source.mapConcat

      • mapContext

        public <Ctx2> SourceWithContext<Out,​Ctx2,​Mat> mapContext​(Function<Ctx,​Ctx2> extractContext)
        Apply the given function to each context element (leaving the data elements unchanged).

      • sliding

        public SourceWithContext<java.util.List<Out>,​java.util.List<Ctx>,​Mat> sliding​(int n,
                                                                                          int step)
        Context-preserving variant of pekko.stream.javadsl.Source.sliding.

        Each output group will be associated with a Seq of corresponding context elements.

        See Also:
        pekko.stream.javadsl.Source.sliding

      • sliding$default$2

        public int sliding$default$2()

      • log

        public SourceWithContext<Out,​Ctx,​Mat> log​(java.lang.String name,
                                                      Function<Out,​java.lang.Object> extract)
        Context-preserving variant of pekko.stream.javadsl.Flow.log.

        See Also:
        pekko.stream.javadsl.Flow.log

      • log

        public SourceWithContext<Out,​Ctx,​Mat> log​(java.lang.String name,
                                                      LoggingAdapter log)
        Context-preserving variant of pekko.stream.javadsl.Flow.log.

        See Also:
        pekko.stream.javadsl.Flow.log

      • log

        public SourceWithContext<Out,​Ctx,​Mat> log​(java.lang.String name)
        Context-preserving variant of pekko.stream.javadsl.Flow.log.

        See Also:
        pekko.stream.javadsl.Flow.log

      • logWithMarker

        public SourceWithContext<Out,​Ctx,​Mat> logWithMarker​(java.lang.String name,
                                                                Function2<Out,​Ctx,​LogMarker> marker,
                                                                Function<Out,​java.lang.Object> extract)
        Context-preserving variant of pekko.stream.javadsl.Flow.logWithMarker.,

        See Also:
        pekko.stream.javadsl.Flow.logWithMarker

      • logWithMarker

        public SourceWithContext<Out,​Ctx,​Mat> logWithMarker​(java.lang.String name,
                                                                Function2<Out,​Ctx,​LogMarker> marker)
        Context-preserving variant of pekko.stream.javadsl.Flow.logWithMarker.

        See Also:
        pekko.stream.javadsl.Flow.logWithMarker

      • throttle

        public SourceWithContext<Out,​Ctx,​Mat> throttle​(int elements,
                                                           java.time.Duration per)
        Context-preserving variant of pekko.stream.javadsl.Source.throttle.

        See Also:
        pekko.stream.javadsl.Source.throttle

      • throttle

        public SourceWithContext<Out,​Ctx,​Mat> throttle​(int elements,
                                                           java.time.Duration per,
                                                           int maximumBurst,
                                                           ThrottleMode mode)
        Context-preserving variant of pekko.stream.javadsl.Source.throttle.

        See Also:
        pekko.stream.javadsl.Source.throttle

      • throttle

        public SourceWithContext<Out,​Ctx,​Mat> throttle​(int cost,
                                                           java.time.Duration per,
                                                           Function<Out,​java.lang.Integer> costCalculation)
        Context-preserving variant of pekko.stream.javadsl.Source.throttle.

        See Also:
        pekko.stream.javadsl.Source.throttle

      • throttle

        public SourceWithContext<Out,​Ctx,​Mat> throttle​(int cost,
                                                           java.time.Duration per,
                                                           int maximumBurst,
                                                           Function<Out,​java.lang.Integer> costCalculation,
                                                           ThrottleMode mode)
        Context-preserving variant of pekko.stream.javadsl.Source.throttle.

        See Also:
        pekko.stream.javadsl.Source.throttle

      • to

        public <Mat2> RunnableGraph<Mat> to​(Graph<SinkShape<Pair<Out,​Ctx>>,​Mat2> sink)
        Connect this pekko.stream.javadsl.SourceWithContext to a pekko.stream.javadsl.Sink, concatenating the processing steps of both.

      • toMat

        public <Mat2,​Mat3> RunnableGraph<Mat3> toMat​(Graph<SinkShape<Pair<Out,​Ctx>>,​Mat2> sink,
                                                   Function2<Mat,​Mat2,​Mat3> combine)
        Connect this pekko.stream.javadsl.SourceWithContext to a pekko.stream.javadsl.Sink, concatenating the processing steps of both.

      • runWith

        public <M> M runWith​(Graph<SinkShape<Pair<Out,​Ctx>>,​M> sink,
                     ClassicActorSystemProvider systemProvider)
        Connect this pekko.stream.javadsl.SourceWithContext to a pekko.stream.javadsl.Sink and run it. The returned value is the materialized value of the Sink.

      • runWith

        public <M> M runWith​(Graph<SinkShape<Pair<Out,​Ctx>>,​M> sink,
                     Materializer materializer)
        Connect this pekko.stream.javadsl.SourceWithContext to a pekko.stream.javadsl.Sink and run it. The returned value is the materialized value of the Sink.

        Prefer the method taking an ActorSystem unless you have special requirements.