Package org.apache.pekko.persistence.typed.state.scaladsl

Class Effect$

java.lang.Object
org.apache.pekko.persistence.typed.state.scaladsl.Effect$
public class Effect$ extends Object
Factory methods for creating Effect directives - how a DurableStateBehavior reacts on a command.

API May Change

  • Field Details

    • MODULE$

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

  • Constructor Details

    • Effect$

      public Effect$()

  • Method Details

    • persist

      public <State> EffectBuilder<State> persist(State state)
      Persist new state.

      Side effects can be chained with thenRun

    • delete

      public <State> EffectBuilder<State> delete()
      Delete the persisted state.

      Side effects can be chained with thenRun

    • none

      public <State> EffectBuilder<State> none()
      Do not persist anything

      Side effects can be chained with thenRun

    • unhandled

      public <State> EffectBuilder<State> unhandled()
      This command is not handled, but it is not an error that it isn't.

      Side effects can be chained with thenRun

    • stop

      public <State> EffectBuilder<State> stop()
      Stop this persistent actor Side effects can be chained with thenRun

    • stash

      public <State> ReplyEffect<State> stash()
      Stash the current command. Can be unstashed later with Effect.unstashAll.

      Note that the stashed commands are kept in an in-memory buffer, so in case of a crash they will not be processed. They will also be discarded if the actor is restarted (or stopped) due to that an exception was thrown from processing a command or side effect after persisting. The stash buffer is preserved for persist failures if a backoff supervisor strategy is defined with DurableStateBehavior.onPersistFailure.

      Side effects can be chained with thenRun

    • unstashAll

      public <State> Effect<State> unstashAll()
      Unstash the commands that were stashed with Effect.stash.

      It's allowed to stash messages while unstashing. Those newly added commands will not be processed by this unstashAll effect and have to be unstashed by another unstashAll.

      See Also:
      • EffectBuilder.thenUnstashAll

    • reply

      public <ReplyMessage, State> ReplyEffect<State> reply(ActorRef<ReplyMessage> replyTo, ReplyMessage replyWithMessage)
      Send a reply message to the command. The type of the reply message must conform to the type specified by the passed replyTo ActorRef.

      This has the same semantics as cmd.replyTo.tell.

      It is provided as a convenience (reducing boilerplate) and a way to enforce that replies are not forgotten when the DurableStateBehavior is created with DurableStateBehavior.withEnforcedReplies. When withEnforcedReplies is used there will be compilation errors if the returned effect isn't a ReplyEffect. The reply message will be sent also if withEnforcedReplies isn't used, but then the compiler will not help finding mistakes.

    • noReply

      public <State> ReplyEffect<State> noReply()
      When DurableStateBehavior.withEnforcedReplies is used there will be compilation errors if the returned effect isn't a ReplyEffect. This noReply can be used as a conscious decision that a reply shouldn't be sent for a specific command or the reply will be sent later.