Package org.apache.pekko.stream.javadsl

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

java.lang.Object

org.apache.pekko.stream.GraphDelegate<FlowShape<Pair<In,CtxIn>,Pair<Out,CtxOut>>,Mat>

org.apache.pekko.stream.javadsl.FlowWithContext<In,CtxIn,Out,CtxOut,Mat>

All Implemented Interfaces:

Graph<FlowShape<Pair<In,CtxIn>,Pair<Out,CtxOut>>,Mat>

public final class FlowWithContext<In,CtxIn,Out,CtxOut,Mat>
extends org.apache.pekko.stream.GraphDelegate<FlowShape<Pair<In,CtxIn>,Pair<Out,CtxOut>>,Mat>

A flow that provides operations which automatically propagate the context of an element. Only a subset of common operations from Flow is supported. As an escape hatch you can use FlowWithContext.via to manually provide the context propagation for otherwise unsupported operations.

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

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.pekko.stream.Graph

Graph.GraphMapMatVal<S extends Shape,M>

Constructor Summary

Constructors

Constructor	Description
FlowWithContext(Flow<Pair<In,CtxIn>,Pair<Out,CtxOut>,Mat> delegate)

Method Summary

Modifier and Type	Method	Description
Flow<Pair<In,CtxIn>,Pair<Out,CtxOut>,Mat>	asFlow()	Creates a regular flow of pairs (data, context).
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	asScala()
<Out2> FlowWithContext<In,CtxIn,Out2,CtxOut,Mat>	collect(scala.PartialFunction<Out,Out2> pf)	Context-preserving variant of pekko.stream.javadsl.Flow.collect.
static <In,Ctx> FlowWithContext<In,Ctx,In,Ctx,NotUsed>	create()
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	filter(Predicate<Out> p)	Context-preserving variant of pekko.stream.javadsl.Flow.filter.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	filterNot(Predicate<Out> p)	Context-preserving variant of pekko.stream.javadsl.Flow.filterNot.
static <In,CtxIn,Out,CtxOut,Mat> FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	fromPairs(Flow<Pair<In,CtxIn>,Pair<Out,CtxOut>,Mat> under)	Creates a FlowWithContext from a regular flow that operates on Pair elements.
FlowWithContext<In,CtxIn,java.util.List<Out>,java.util.List<CtxOut>,Mat>	grouped(int n)	Context-preserving variant of pekko.stream.javadsl.Flow.grouped.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	log(java.lang.String name)	Context-preserving variant of pekko.stream.javadsl.Flow.log.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	log(java.lang.String name, LoggingAdapter log)	Context-preserving variant of pekko.stream.javadsl.Flow.log.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	log(java.lang.String name, Function<Out,java.lang.Object> extract)	Context-preserving variant of pekko.stream.javadsl.Flow.log.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	log(java.lang.String name, Function<Out,java.lang.Object> extract, LoggingAdapter log)	Context-preserving variant of pekko.stream.javadsl.Flow.log.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	logWithMarker(java.lang.String name, Function2<Out,CtxOut,LogMarker> marker)	Context-preserving variant of pekko.stream.javadsl.Flow.logWithMarker.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	logWithMarker(java.lang.String name, Function2<Out,CtxOut,LogMarker> marker, MarkerLoggingAdapter log)	Context-preserving variant of pekko.stream.javadsl.Flow.logWithMarker.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	logWithMarker(java.lang.String name, Function2<Out,CtxOut,LogMarker> marker, Function<Out,java.lang.Object> extract)	Context-preserving variant of pekko.stream.javadsl.Flow.logWithMarker.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	logWithMarker(java.lang.String name, Function2<Out,CtxOut,LogMarker> marker, Function<Out,java.lang.Object> extract, MarkerLoggingAdapter log)	Context-preserving variant of pekko.stream.javadsl.Flow.logWithMarker.
<Out2> FlowWithContext<In,CtxIn,Out2,CtxOut,Mat>	map(Function<Out,Out2> f)	Context-preserving variant of pekko.stream.javadsl.Flow.map.
<Out2> FlowWithContext<In,CtxIn,Out2,CtxOut,Mat>	mapAsync(int parallelism, Function<Out,java.util.concurrent.CompletionStage<Out2>> f)
<Out2> FlowWithContext<In,CtxIn,Out2,CtxOut,Mat>	mapConcat(Function<Out,? extends java.lang.Iterable<Out2>> f)	Context-preserving variant of pekko.stream.javadsl.Flow.mapConcat.
<CtxOut2> FlowWithContext<In,CtxIn,Out,CtxOut2,Mat>	mapContext(Function<CtxOut,CtxOut2> extractContext)	Apply the given function to each context element (leaving the data elements unchanged).
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	mapError(scala.PartialFunction<java.lang.Throwable,java.lang.Throwable> pf)	Context-preserving variant of pekko.stream.javadsl.Flow.mapError.
<Mat2> FlowWithContext<In,CtxIn,Out,CtxOut,Mat2>	mapMaterializedValue(Function<Mat,Mat2> f)	Context-preserving variant of pekko.stream.javadsl.Flow.mapMaterializedValue.
FlowWithContext<In,CtxIn,java.util.List<Out>,java.util.List<CtxOut>,Mat>	sliding(int n, int step)	Context-preserving variant of pekko.stream.javadsl.Flow.sliding.
int	sliding$default$2()
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	throttle(int elements, java.time.Duration per)	Context-preserving variant of pekko.stream.javadsl.Flow.throttle.
FlowWithContext<In,CtxIn,Out,CtxOut,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.Flow.throttle.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	throttle(int elements, java.time.Duration per, int maximumBurst, ThrottleMode mode)	Context-preserving variant of pekko.stream.javadsl.Flow.throttle.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	throttle(int cost, java.time.Duration per, Function<Out,java.lang.Integer> costCalculation)	Context-preserving variant of pekko.stream.javadsl.Flow.throttle.
<Out2,Mat2> FlowWithContext<In,CtxIn,Out2,CtxOut,Mat>	unsafeDataVia(Graph<FlowShape<Out,Out2>,Mat2> viaFlow)	Transform this flow by the regular flow.
<Out2,CtxOut2,Mat2> FlowWithContext<In,CtxIn,Out2,CtxOut2,Mat>	via(Graph<FlowShape<Pair<Out,CtxOut>,Pair<Out2,CtxOut2>>,Mat2> viaFlow)	Transform this flow by the regular flow.
FlowWithContext<In,CtxIn,Out,CtxOut,Mat>	withAttributes(Attributes attr)	Context-preserving variant of pekko.stream.javadsl.Flow.withAttributes.

Methods inherited from class org.apache.pekko.stream.GraphDelegate

addAttributes, async, async, async, getAttributes, named, shape, traversalBuilder

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FlowWithContext

public FlowWithContext(Flow<Pair<In,CtxIn>,Pair<Out,CtxOut>,Mat> delegate)

Method Detail

create

public static <In,Ctx> FlowWithContext<In,Ctx,In,Ctx,NotUsed> create()

fromPairs

public static <In,CtxIn,Out,CtxOut,Mat> FlowWithContext<In,CtxIn,Out,CtxOut,Mat> fromPairs(Flow<Pair<In,CtxIn>,Pair<Out,CtxOut>,Mat> under)

Creates a FlowWithContext from a regular flow that operates on Pair elements.

via

public <Out2,CtxOut2,Mat2> FlowWithContext<In,CtxIn,Out2,CtxOut2,Mat> via(Graph<FlowShape<Pair<Out,CtxOut>,Pair<Out2,CtxOut2>>,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> FlowWithContext<In,CtxIn,Out2,CtxOut,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 FlowWithContext<In,CtxIn,Out,CtxOut,Mat> withAttributes(Attributes attr)

Context-preserving variant of pekko.stream.javadsl.Flow.withAttributes.

See Also:

pekko.stream.javadsl.Flow.withAttributes

mapError

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> mapError(scala.PartialFunction<java.lang.Throwable,java.lang.Throwable> pf)

Context-preserving variant of pekko.stream.javadsl.Flow.mapError.

See Also:

pekko.stream.javadsl.Flow.mapError

mapMaterializedValue

public <Mat2> FlowWithContext<In,CtxIn,Out,CtxOut,Mat2> mapMaterializedValue(Function<Mat,Mat2> f)

Context-preserving variant of pekko.stream.javadsl.Flow.mapMaterializedValue.

See Also:

pekko.stream.javadsl.Flow.mapMaterializedValue

asFlow

public Flow<Pair<In,CtxIn>,Pair<Out,CtxOut>,Mat> asFlow()

Creates a regular flow of pairs (data, context).

collect

public <Out2> FlowWithContext<In,CtxIn,Out2,CtxOut,Mat> collect(scala.PartialFunction<Out,Out2> pf)

Context-preserving variant of pekko.stream.javadsl.Flow.collect.

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

See Also:

pekko.stream.javadsl.Flow.collect

filter

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> filter(Predicate<Out> p)

Context-preserving variant of pekko.stream.javadsl.Flow.filter.

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

See Also:

pekko.stream.javadsl.Flow.filter

filterNot

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> filterNot(Predicate<Out> p)

Context-preserving variant of pekko.stream.javadsl.Flow.filterNot.

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

See Also:

pekko.stream.javadsl.Flow.filterNot

grouped

public FlowWithContext<In,CtxIn,java.util.List<Out>,java.util.List<CtxOut>,Mat> grouped(int n)

Context-preserving variant of pekko.stream.javadsl.Flow.grouped.

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

See Also:

pekko.stream.javadsl.Flow.grouped

map

public <Out2> FlowWithContext<In,CtxIn,Out2,CtxOut,Mat> map(Function<Out,Out2> f)

Context-preserving variant of pekko.stream.javadsl.Flow.map.

See Also:

pekko.stream.javadsl.Flow.map

mapAsync

public <Out2> FlowWithContext<In,CtxIn,Out2,CtxOut,Mat> mapAsync(int parallelism,
                                                                                         Function<Out,java.util.concurrent.CompletionStage<Out2>> f)

mapConcat

public <Out2> FlowWithContext<In,CtxIn,Out2,CtxOut,Mat> mapConcat(Function<Out,? extends java.lang.Iterable<Out2>> f)

Context-preserving variant of pekko.stream.javadsl.Flow.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.Flow.mapConcat

mapContext

public <CtxOut2> FlowWithContext<In,CtxIn,Out,CtxOut2,Mat> mapContext(Function<CtxOut,CtxOut2> extractContext)

Apply the given function to each context element (leaving the data elements unchanged).

sliding

public FlowWithContext<In,CtxIn,java.util.List<Out>,java.util.List<CtxOut>,Mat> sliding(int n,
                                                                                                                int step)

Context-preserving variant of pekko.stream.javadsl.Flow.sliding.

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

See Also:

pekko.stream.javadsl.Flow.sliding

sliding$default$2

public int sliding$default$2()

log

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> log(java.lang.String name,
                                                                            Function<Out,java.lang.Object> extract,
                                                                            LoggingAdapter log)

Context-preserving variant of pekko.stream.javadsl.Flow.log.

See Also:

pekko.stream.javadsl.Flow.log

log

public FlowWithContext<In,CtxIn,Out,CtxOut,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 FlowWithContext<In,CtxIn,Out,CtxOut,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 FlowWithContext<In,CtxIn,Out,CtxOut,Mat> log(java.lang.String name)

Context-preserving variant of pekko.stream.javadsl.Flow.log.

See Also:

pekko.stream.javadsl.Flow.log

logWithMarker

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> logWithMarker(java.lang.String name,
                                                                                      Function2<Out,CtxOut,LogMarker> marker,
                                                                                      Function<Out,java.lang.Object> extract,
                                                                                      MarkerLoggingAdapter log)

Context-preserving variant of pekko.stream.javadsl.Flow.logWithMarker.

See Also:

pekko.stream.javadsl.Flow.logWithMarker

logWithMarker

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> logWithMarker(java.lang.String name,
                                                                                      Function2<Out,CtxOut,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 FlowWithContext<In,CtxIn,Out,CtxOut,Mat> logWithMarker(java.lang.String name,
                                                                                      Function2<Out,CtxOut,LogMarker> marker,
                                                                                      MarkerLoggingAdapter log)

Context-preserving variant of pekko.stream.javadsl.Flow.logWithMarker.

See Also:

pekko.stream.javadsl.Flow.logWithMarker

logWithMarker

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> logWithMarker(java.lang.String name,
                                                                                      Function2<Out,CtxOut,LogMarker> marker)

Context-preserving variant of pekko.stream.javadsl.Flow.logWithMarker.

See Also:

pekko.stream.javadsl.Flow.logWithMarker

throttle

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> throttle(int elements,
                                                                                 java.time.Duration per)

Context-preserving variant of pekko.stream.javadsl.Flow.throttle.

See Also:

pekko.stream.javadsl.Flow.throttle

throttle

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> throttle(int elements,
                                                                                 java.time.Duration per,
                                                                                 int maximumBurst,
                                                                                 ThrottleMode mode)

Context-preserving variant of pekko.stream.javadsl.Flow.throttle.

See Also:

pekko.stream.javadsl.Flow.throttle

throttle

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> throttle(int cost,
                                                                                 java.time.Duration per,
                                                                                 Function<Out,java.lang.Integer> costCalculation)

Context-preserving variant of pekko.stream.javadsl.Flow.throttle.

See Also:

pekko.stream.javadsl.Flow.throttle

throttle

public FlowWithContext<In,CtxIn,Out,CtxOut,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.Flow.throttle.

See Also:

pekko.stream.javadsl.Flow.throttle

asScala

public FlowWithContext<In,CtxIn,Out,CtxOut,Mat> asScala()