Package org.apache.pekko.stream

Class Attributes$

  • All Implemented Interfaces:
    java.io.Serializable
    public class Attributes$
extends java.lang.Object
implements java.io.Serializable
    Note that more attributes for the Materializer are defined in ActorAttributes.
    See Also:
    Serialized Form

    • Field Detail

      • MODULE$

        public static final Attributes$ MODULE$
        Static reference to the singleton instance of this Scala object.

    • Constructor Detail

      • Attributes$

        public Attributes$()

    • Method Detail

      • $lessinit$greater$default$1

        public scala.collection.immutable.List<Attributes.Attribute> $lessinit$greater$default$1()

      • cancellationStrategyCompleteState

        public org.apache.pekko.stream.Attributes.CancellationStrategy.Strategy cancellationStrategyCompleteState()
        Java API

        Strategy that treats cancelStage the same as completeStage, i.e. all inlets are cancelled (propagating the cancellation cause) and all outlets are regularly completed.

        This used to be the default behavior before Akka 2.6.

        This behavior can be problematic in stacks of BidiFlows where different layers of the stack are both connected through inputs and outputs. In this case, an error in a doubly connected component triggers both a cancellation going upstream and an error going downstream. Since the stack might be connected to those components with inlets and outlets, a race starts whether the cancellation or the error arrives first. If the error arrives first, that's usually good because then the error can be propagated both on inlets and outlets. However, if the cancellation arrives first, the previous default behavior to complete the stage will lead other outputs to be completed regularly. The error which arrive late at the other hand will just be ignored (that connection will have been cancelled already and also the paths through which the error could propagates are already shut down).

      • cancellationStrategyFailStage

        public org.apache.pekko.stream.Attributes.CancellationStrategy.Strategy cancellationStrategyFailStage()
        Java API

        Strategy that treats cancelStage the same as failStage, i.e. all inlets are cancelled (propagating the cancellation cause) and all outlets are failed propagating the cause from cancellation.

      • cancellationStrategyPropagateFailure

        public org.apache.pekko.stream.Attributes.CancellationStrategy.Strategy cancellationStrategyPropagateFailure()
        Java API

        Strategy that treats cancelStage in different ways depending on the cause that was given to the cancellation.

        If the cause was a regular, active cancellation (SubscriptionWithCancelException.NoMoreElementsNeeded), the stage receiving this cancellation is completed regularly.

        If another cause was given, this is treated as an error and the behavior is the same as with failStage.

        This is a good default strategy.

      • cancellationStrategyAfterDelay

        public org.apache.pekko.stream.Attributes.CancellationStrategy.Strategy cancellationStrategyAfterDelay​(scala.concurrent.duration.FiniteDuration delay,
                                                                                                       org.apache.pekko.stream.Attributes.CancellationStrategy.Strategy strategy)
        Java API

        Strategy that allows to delay any action when cancelStage is invoked.

        The idea of this strategy is to delay any action on cancellation because it is expected that the stage is completed through another path in the meantime. The downside is that a stage and a stream may live longer than expected if no such signal is received and cancellation is invoked later on. In streams with many stages that all apply this strategy, this strategy might significantly delay the propagation of a cancellation signal because each upstream stage might impose such a delay. During this time, the stream will be mostly "silent", i.e. it cannot make progress because of backpressure, but you might still be able observe a long delay at the ultimate source.

      • nestedMaterializationCancellationPolicyEagerCancellation

        public Attributes.NestedMaterializationCancellationPolicy nestedMaterializationCancellationPolicyEagerCancellation()
        JAVA API A NestedMaterializationCancellationPolicy that configures graph stages delaying nested flow materialization to cancel immediately when downstream cancels before nested flow materialization. This applies to pekko.stream.scaladsl.FlowOps.flatMapPrefix, pekko.stream.scaladsl.Flow.futureFlow and derived operators.

      • nestedMaterializationCancellationPolicyPropagateToNested

        public Attributes.NestedMaterializationCancellationPolicy nestedMaterializationCancellationPolicyPropagateToNested()
        JAVA API A NestedMaterializationCancellationPolicy that configures graph stages delaying nested flow materialization to delay cancellation when downstream cancels before nested flow materialization. Once the nested flow is materialized it will be cancelled immediately. This applies to pekko.stream.scaladsl.FlowOps.flatMapPrefix, pekko.stream.scaladsl.Flow.futureFlow and derived operators.

      • nestedMaterializationCancellationPolicyDefault

        public Attributes.NestedMaterializationCancellationPolicy nestedMaterializationCancellationPolicyDefault()
        Default NestedMaterializationCancellationPolicy, please see pekko.stream.Attributes#nestedMaterializationCancellationPolicyEagerCancellation() for details.

      • asyncBoundary

        public Attributes asyncBoundary()

      • name

        public Attributes name​(java.lang.String name)
        Specifies the name of the operation. If the name is null or empty the name is ignored, i.e. none() is returned.

      • inputBuffer

        public Attributes inputBuffer​(int initial,
                              int max)
        Each asynchronous piece of a materialized stream topology is executed by one Actor that manages an input buffer for all inlets of its shape. This attribute configures the initial and maximal input buffer in number of elements for each inlet.

      • createLogLevels

        public Attributes createLogLevels​(Logging.LogLevel onElement)
        Java API

        Configures log() operator log-levels to be used when logging onElement. Logging a certain operation can be completely disabled by using Attributes.logLevelOff().

      • logLevels

        public Attributes logLevels​(Logging.LogLevel onElement,
                            Logging.LogLevel onFinish,
                            Logging.LogLevel onFailure)
        Configures log() operator log-levels to be used when logging. Logging a certain operation can be completely disabled by using LogLevels.Off.

        See Attributes.createLogLevels for Java API

      • extractName

        public java.lang.String extractName​(org.apache.pekko.stream.impl.TraversalBuilder builder,
                                    java.lang.String default_)
        Compute a name by concatenating all Name attributes that the given module has, returning the given default value if none are found.