Override this handler to define the action on Domain Event

Id of the persistent entity for which messages should be replayed.

This extractor is just convenience for matching a (S, S) pair, including a reminder what the new state is.

Default reason if calling stop().

Reason given when someone was calling system.stop(fsm) from outside; also applies to Stop supervision directive.

This case object is received in case of a state timeout.

INTERNAL API.

INTERNAL API.

INTERNAL API.

INTERNAL API.

INTERNAL API.

Cancel named timer, ensuring that the message is not subsequently delivered (no race).

Scala API: Stores the context for this actor, including self, and sender. It is implicit to support operations such as forward.

WARNING: Only valid within the Actor itself, so do not close over it and publish it to other threads!

pekko.actor.ActorContext is the Scala API. getContext returns a pekko.actor.AbstractActor.ActorContext, which is the Java API of the actor context.

Defer the handler execution until all pending handlers have been executed. It is guaranteed that no new commands will be received by a persistent actor between a call to defer and the execution of its handler. Allows to define logic within the actor, which will respect the invocation-order-guarantee in respect to persistAsync or persist calls. That is, if persistAsync or persist was invoked before defer, the corresponding handlers will be invoked in the same order as they were registered in.

This call will NOT result in event being persisted, use persist or persistAsync instead if the given event should possible to replay.

If there are no pending persist handler calls, the handler will be called immediately.

If persistence of an earlier event fails, the persistent actor will stop, and the handler will not be run.

Defer the handler execution until all pending handlers have been executed. Allows to define logic within the actor, which will respect the invocation-order-guarantee in respect to persistAsync or persist calls. That is, if persistAsync or persist was invoked before deferAsync, the corresponding handlers will be invoked in the same order as they were registered in.

This call will NOT result in event being persisted, use persist or persistAsync instead if the given event should possible to replay.

If there are no pending persist handler calls, the handler will be called immediately.

If persistence of an earlier event fails, the persistent actor will stop, and the handler will not be run.

Permanently deletes all persistent messages with sequence numbers less than or equal toSequenceNr.

If the delete is successful a pekko.persistence.DeleteMessagesSuccess will be sent to the actor. If the delete fails a pekko.persistence.DeleteMessagesFailure will be sent to the actor.

The given toSequenceNr must be less than or equal to Eventsourced#lastSequenceNr, otherwise pekko.persistence.DeleteMessagesFailure is sent to the actor without performing the delete. All persistent messages may be deleted without specifying the actual sequence number by using Long.MaxValue as the toSequenceNr.

Deletes the snapshot identified by sequenceNr.

The PersistentActor will be notified about the status of the deletion via an DeleteSnapshotSuccess or DeleteSnapshotFailure message.

Deletes all snapshots matching criteria.

The PersistentActor will be notified about the status of the deletion via an DeleteSnapshotsSuccess or DeleteSnapshotsFailure message.

Adapter from Java java.lang.Class to scala.reflect.ClassTag

Domain event's scala.reflect.ClassTag Used for identifying domain events during recovery

Adapter from Java 8 Functional Interface to Scala Function

Returns this AbstractActor's ActorContext The ActorContext is not thread safe so do not expose it outside of the AbstractActor.

Returns the ActorRef for this actor.

Same as self().

The reference sender Actor of the currently processed message. This is always a legal destination to send to, even if there is no logical recipient for the reply, in which case it will be sent to the dead letter mailbox.

Same as sender().

WARNING: Only valid within the Actor itself, so do not close over it and publish it to other threads!

Produce transition to other state. Return this from a state function in order to effect the transition.

Sends the supplied message to all current listeners using the provided sender() as sender.

Produce transition to other state. Return this from a state function in order to effect the transition.

This method always triggers transition events, even for A -> A transitions. If you want to stay in the same state without triggering an state transition event use #stay instead.

The returned pekko.persistence.StashOverflowStrategy object determines how to handle the message failed to stash when the internal Stash capacity exceeded.

Inquire whether the named timer is still active. Returns true unless the timer does not exist, has previously been canceled or if it was a single-shot timer whose message was already received.

Configuration id of the journal plugin servicing this persistent actor. When empty, looks in pekko.persistence.journal.plugin to find configuration entry path. When configured, uses journalPluginId as absolute path to the journal configuration entry. Configuration entry must contain few required fields, such as class. See src/main/resources/reference.conf.

Highest received sequence number so far or 0L if this actor hasn't replayed or stored any persistent events yet.

Chain this into the receive function.

def receive = listenerManagement orElse …

Instructs the snapshot store to load the specified snapshot and send it via an SnapshotOffer to the running PersistentActor.

By default PersistentFSM.Failure is logged at error level and other reason types are not logged. It is possible to override this behavior.

Create an pekko.japi.pf.FSMStateFunctionBuilder with the first case statement set.

A case statement that matches on any type of event.

Create a pekko.japi.pf.UnitPFBuilder with the first case statement set.

Create a pekko.japi.pf.UnitPFBuilder with the first case statement set.

Create an pekko.japi.pf.FSMStateFunctionBuilder with the first case statement set.

A case statement that matches if any of the event types in the list match or any of the event instances in the list compares equal.

Create an pekko.japi.pf.FSMStateFunctionBuilder with the first case statement set.

A case statement that matches on the data type and if any of the event types in the list match or any of the event instances in the list compares equal.

Create an pekko.japi.pf.FSMStateFunctionBuilder with the first case statement set.

A case statement that matches if the predicate matches.

Create an pekko.japi.pf.FSMStateFunctionBuilder with the first case statement set.

A case statement that matches if the event type matches.

Create an pekko.japi.pf.FSMStateFunctionBuilder with the first case statement set.

A case statement that matches if the event type and predicate matches.

Create an pekko.japi.pf.FSMStateFunctionBuilder with the first case statement set.

A case statement that matches on an event and data type.

Create an pekko.japi.pf.FSMStateFunctionBuilder with the first case statement set.

A case statement that matches on an event and data type and a predicate.

Create an pekko.japi.pf.FSMStateFunctionBuilder with the first case statement set.

A case statement that matches if the event compares equal.

Create an pekko.japi.pf.FSMStateFunctionBuilder with the first case statement set.

A case statement that matches on the data type and if the event compares equal.

Create an pekko.japi.pf.FSMTransitionHandlerBuilder with the first case statement set.

A case statement that matches on a from state and a to state.

Create an pekko.japi.pf.FSMTransitionHandlerBuilder with the first case statement set.

A case statement that matches on a from state and a to state.

Create an pekko.japi.pf.FSMStopBuilder with the first case statement set.

A case statement that matches on a reason type and a predicate.

Create an pekko.japi.pf.FSMStopBuilder with the first case statement set.

A case statement that matches on a reason type.

Create an pekko.japi.pf.FSMStopBuilder with the first case statement set.

A case statement that matches on an PersistentFSM.Reason.

Return next state data (available in onTransition handlers)

Called when persist fails. By default it logs the error. Subclass may override to customize logging and for example send negative acknowledgment to sender.

The actor is always stopped after this method has been invoked.

Note that the event may or may not have been saved, depending on the type of failure.

Called when the journal rejected persist of an event. The event was not stored. By default this method logs the problem as an error, and the actor continues. The callback handler that was passed to the persist method will not be invoked.

Override this handler to define the action on recovery completion

Called whenever a message replay fails. By default it logs the error.

Subclass may override to customize logging.

The actor is always stopped after this method has been invoked.

Set handler which is called upon termination of this FSM actor. Calling this method again will overwrite the previous contents.

Set handler which is called upon termination of this FSM actor. Calling this method again will overwrite the previous contents.

Add a handler which is called upon each state transition, i.e. not when staying in the same state.

Multiple handlers may be installed, and every one of them will be called, not only the first one matching.

Add a handler which is called upon each state transition, i.e. not when staying in the same state.

Multiple handlers may be installed, and every one of them will be called, not only the first one matching.

Set handler which is called upon each state transition, i.e. not when staying in the same state. This may use the pair extractor defined in the FSM companion object like so:

onTransition {
  case Old -> New => doSomething
}

It is also possible to supply a 2-ary function object:

onTransition(handler _)

private def handler(from: S, to: S) { ... }

The underscore is unfortunately necessary to enable the nicer syntax shown above (it uses the implicit conversion total2pf under the hood).

Multiple handlers may be installed, and every one of them will be called, not only the first one matching.

Asynchronously persists event. On successful persistence, handler is called with the persisted event. It is guaranteed that no new commands will be received by a persistent actor between a call to persist and the execution of its handler. This also holds for multiple persist calls per received command. Internally, this is achieved by stashing new commands and unstashing them when the event has been persisted and handled. The stash used for that is an internal stash which doesn't interfere with the inherited user stash.

An event handler may close over persistent actor state and modify it. The sender of a persisted event is the sender of the corresponding command. This means that one can reply to a command sender within an event handler.

Within an event handler, applications usually update persistent actor state using persisted event data, notify listeners and reply to command senders.

If persistence of an event fails, #onPersistFailure will be invoked and the actor will unconditionally be stopped. The reason that it cannot resume when persist fails is that it is unknown if the event was actually persisted or not, and therefore it is in an inconsistent state. Restarting on persistent failures will most likely fail anyway, since the journal is probably unavailable. It is better to stop the actor and after a back-off timeout start it again.

Asynchronously persists events in specified order. This is equivalent to calling persist[A](event: A)(handler: A => Unit) multiple times with the same handler, except that events are persisted atomically with this method.

Asynchronously persists events in specified order. This is equivalent to calling persistAsync[A](event: A)(handler: A => Unit) multiple times with the same handler, except that events are persisted atomically with this method.

Asynchronously persists event. On successful persistence, handler is called with the persisted event.

Unlike persist the persistent actor will continue to receive incoming commands between the call to persist and executing it's handler. This asynchronous, non-stashing, version of of persist should be used when you favor throughput over the "command-2 only processed after command-1 effects' have been applied" guarantee, which is provided by the plain persist method.

An event handler may close over persistent actor state and modify it. The sender of a persisted event is the sender of the corresponding command. This means that one can reply to a command sender within an event handler.

If persistence of an event fails, #onPersistFailure will be invoked and the actor will unconditionally be stopped. The reason that it cannot resume when persist fails is that it is unknown if the event was actually persisted or not, and therefore it is in an inconsistent state. Restarting on persistent failures will most likely fail anyway, since the journal is probably unavailable. It is better to stop the actor and after a back-off timeout start it again.

User overridable callback: By default it calls preStart().

Overridden callback. Prepends all messages in the stash to the mailbox and clears the stash. Must be called when overriding this method, otherwise stashed messages won't be propagated to DeadLetters when actor stops.

Overridden callback. Prepends all messages in the stash to the mailbox, clears the stash, stops all children and invokes the postStop() callback.

User overridable callback.

Is called when an Actor is started. Actors are automatically started asynchronously when created. Empty default implementation.

Scala API: This defines the initial actor behavior, it must return a partial function with the actor logic.

After recovery events are handled as in usual FSM actor

Discover the latest recorded state

Called when the persistent actor is started for the first time. The returned pekko.persistence.Recovery object defines how the Actor will recover its persistent state before handling the first incoming message.

To skip recovery completely return Recovery.none.

Returns true if this persistent actor has successfully finished recovery.

Returns true if this persistent actor is currently recovering.

Saves a snapshot of this snapshotter's state.

The PersistentActor will be notified about the success or failure of this via an SaveSnapshotSuccess or SaveSnapshotFailure message.

Save the current state as a snapshot

The 'self' field holds the ActorRef for this actor.

Can be used to send messages to itself:

self ! message

The reference sender Actor of the last received message. Is defined if the message was sent from another Actor, else deadLetters in pekko.actor.ActorSystem.

WARNING: Only valid within the Actor itself, so do not close over it and publish it to other threads!

Set state timeout explicitly. This method can safely be used from within a state handler.

Configuration id of the snapshot plugin servicing this persistent actor. When empty, looks in pekko.persistence.snapshot-store.plugin to find configuration entry path. When configured, uses snapshotPluginId as absolute path to the snapshot store configuration entry. Configuration entry must contain few required fields, such as class. See src/main/resources/reference.conf.

Returns lastSequenceNr.

Returns persistenceId.

Start a timer that will send msg once to the self actor after the given delay.

Each timer has a name and if a new timer with same name is started the previous is cancelled. It is guaranteed that a message from the previous timer is not received, even if it was already enqueued in the mailbox when the new timer was started.

Start a timer that will send msg once to the self actor after the given delay.

Each timer has a name and if a new timer with same name is started the previous is cancelled. It is guaranteed that a message from the previous timer is not received, even if it was already enqueued in the mailbox when the new timer was started.

Schedules a message to be sent repeatedly to the self actor with a given frequency.

It will compensate the delay for a subsequent message if the sending of previous message was delayed more than specified. In such cases, the actual message interval will differ from the interval passed to the method.

If the execution is delayed longer than the interval, the subsequent message will be sent immediately after the prior one. This also has the consequence that after long garbage collection pauses or other reasons when the JVM was suspended all "missed" messages will be sent when the process wakes up again.

In the long run, the frequency of messages will be exactly the reciprocal of the specified interval.

Warning: startTimerAtFixedRate can result in bursts of scheduled messages after long garbage collection pauses, which may in worst case cause undesired load on the system. Therefore startTimerWithFixedDelay is often preferred.

Each timer has a name and if a new timer with same name is started the previous is cancelled. It is guaranteed that a message from the previous timer is not received, even if it was already enqueued in the mailbox when the new timer was started.

Schedules a message to be sent repeatedly to the self actor with a given frequency.

It will compensate the delay for a subsequent message if the sending of previous message was delayed more than specified. In such cases, the actual message interval will differ from the interval passed to the method.

If the execution is delayed longer than the interval, the subsequent message will be sent immediately after the prior one. This also has the consequence that after long garbage collection pauses or other reasons when the JVM was suspended all "missed" messages will be sent when the process wakes up again.

In the long run, the frequency of messages will be exactly the reciprocal of the specified interval.

Warning: startTimerAtFixedRate can result in bursts of scheduled messages after long garbage collection pauses, which may in worst case cause undesired load on the system. Therefore startTimerWithFixedDelay is often preferred.

Each timer has a name and if a new timer with same name is started the previous is cancelled. It is guaranteed that a message from the previous timer is not received, even if it was already enqueued in the mailbox when the new timer was started.

Schedules a message to be sent repeatedly to the self actor with a fixed delay between messages.

It will not compensate the delay between messages if scheduling is delayed longer than specified for some reason. The delay between sending of subsequent messages will always be (at least) the given delay.

In the long run, the frequency of messages will generally be slightly lower than the reciprocal of the specified delay.

Each timer has a name and if a new timer with same name is started the previous is cancelled. It is guaranteed that a message from the previous timer is not received, even if it was already enqueued in the mailbox when the new timer was started.

Schedules a message to be sent repeatedly to the self actor with a fixed delay between messages.

It will not compensate the delay between messages if scheduling is delayed longer than specified for some reason. The delay between sending of subsequent messages will always be (at least) the given delay.

In the long run, the frequency of messages will generally be slightly lower than the reciprocal of the specified delay.

Each timer has a name and if a new timer with same name is started the previous is cancelled. It is guaranteed that a message from the previous timer is not received, even if it was already enqueued in the mailbox when the new timer was started.

Set initial state. Call this method from the constructor before the #initialize method. If different state is needed after a restart this method, followed by #initialize, can be used in the actor life cycle hooks pekko.actor.Actor#preStart and pekko.actor.Actor#postRestart.

Set initial state. Call this method from the constructor before the #initialize method. If different state is needed after a restart this method, followed by #initialize, can be used in the actor life cycle hooks pekko.actor.Actor#preStart and pekko.actor.Actor#postRestart.

Set initial state. Call this method from the constructor before the #initialize method. If different state is needed after a restart this method, followed by #initialize, can be used in the actor life cycle hooks pekko.actor.Actor#preStart and pekko.actor.Actor#postRestart.

Adds the current message (the message that the actor received last) to the actor's stash.

Return current state data (i.e. object of type D)

Return current state name (i.e. object of type S)

Map from state identifier to state instance

Produce "empty" transition descriptor. Return this from a state function when no state change is to be effected.

No transition event will be triggered by #stay. If you want to trigger an event like S -> S for onTransition to handle use goto instead.

Produce change descriptor to stop this FSM actor including specified reason.

Produce change descriptor to stop this FSM actor including specified reason.

Produce change descriptor to stop this FSM actor with reason "Normal".

User overridable definition the strategy to use for supervising child actors.

Convenience wrapper for using a total function instead of a partial function literal. To be used with onTransition.

User overridable callback.

Is called when a message isn't handled by the current behavior of the actor by default it fails with either a pekko.actor.DeathPactException (in case of an unhandled pekko.actor.Terminated message) or publishes an pekko.actor.UnhandledMessage to the actor's system's pekko.event.EventStream

Prepends all messages in the stash to the mailbox, and then clears the stash.

Messages from the stash are enqueued to the mailbox until the capacity of the mailbox (if any) has been reached. In case a bounded mailbox overflows, a MessageQueueAppendFailedException is thrown.

The stash is guaranteed to be empty after calling unstashAll().

Insert a new StateFunction at the end of the processing chain for the given state. If the stateTimeout parameter is set, entering this state without a differing explicit timeout setting will trigger a StateTimeout event; the same is true when using #stay.

Insert a new StateFunction at the end of the processing chain for the given state.

Insert a new StateFunction at the end of the processing chain for the given state.

Insert a new StateFunction at the end of the processing chain for the given state. If the stateTimeout parameter is set, entering this state without a differing explicit timeout setting will trigger a StateTimeout event; the same is true when using #stay.

Set handler which is called upon reception of unhandled messages. Calling this method again will overwrite the previous contents.

The current state may be queried using stateName.

Set handler which is called upon reception of unhandled messages. Calling this method again will overwrite the previous contents.

The current state may be queried using stateName.

Schedule named timer to deliver message after given delay, possibly repeating. Any existing timer with the same name will automatically be canceled before adding the new timer.

Schedule named timer to deliver message after given delay, possibly repeating. Any existing timer with the same name will automatically be canceled before adding the new timer.