Packages

trait PersistentFSM[S <: FSMState, D, E] extends PersistentActor with PersistentFSMBase[S, D, E] with ActorLogging

A FSM implementation with persistent state.

Supports the usual akka.actor.FSM functionality with additional persistence features. PersistentFSM is identified by 'persistenceId' value. State changes are persisted atomically together with domain events, which means that either both succeed or both fail, i.e. a state transition event will not be stored if persistence of an event related to that change fails. Persistence execution order is: persist -> wait for ack -> apply state. Incoming messages are deferred until the state is applied. State Data is constructed based on domain events, according to user's implementation of applyEvent function.

Source
PersistentFSM.scala
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  1. PersistentFSM
  2. PersistentFSMBase
  3. ActorLogging
  4. Listeners
  5. PersistentActor
  6. Eventsourced
  7. PersistenceRecovery
  8. PersistenceIdentity
  9. PersistenceStash
  10. StashFactory
  11. Stash
  12. RequiresMessageQueue
  13. UnrestrictedStash
  14. StashSupport
  15. Snapshotter
  16. Actor
  17. AnyRef
  18. Any
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Type Members

  1. type Event = PersistentFSM.Event[D]
    Definition Classes
    PersistentFSMBase
  2. type Receive = PartialFunction[Any, Unit]
    Definition Classes
    Actor
  3. type State = PersistentFSM.State[S, D, E]
    Definition Classes
    PersistentFSMBase
  4. type StateFunction = PartialFunction[Event, State]
    Definition Classes
    PersistentFSMBase
  5. type StopEvent = PersistentFSM.StopEvent[S, D]
    Definition Classes
    PersistentFSMBase
  6. type Timeout = Option[FiniteDuration]
    Definition Classes
    PersistentFSMBase
  7. type TransitionHandler = PartialFunction[(S, S), Unit]
    Definition Classes
    PersistentFSMBase
  8. final class TransformHelper extends AnyRef
    Definition Classes
    PersistentFSMBase

Abstract Value Members

  1. abstract def applyEvent(domainEvent: E, currentData: D): D

    Override this handler to define the action on Domain Event

    Override this handler to define the action on Domain Event

    domainEvent

    domain event to apply

    currentData

    state data of the previous state

    returns

    updated state data

  2. implicit abstract def domainEventClassTag: ClassTag[E]

    Enables to pass a ClassTag of a domain event base type from the implementing class

    Enables to pass a ClassTag of a domain event base type from the implementing class

    returns

    scala.reflect.ClassTag of domain event base type

  3. abstract def persistenceId: String

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

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

    Definition Classes
    PersistenceIdentity

Concrete Value Members

  1. val ->: PersistentFSM.->.type

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

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

    Definition Classes
    PersistentFSMBase
  2. val Event: PersistentFSM.Event.type
    Definition Classes
    PersistentFSMBase
  3. val StateTimeout: PersistentFSM.StateTimeout.type

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

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

    Definition Classes
    PersistentFSMBase
  4. val StopEvent: PersistentFSM.StopEvent.type
    Definition Classes
    PersistentFSMBase
  5. final def cancelTimer(name: String): Unit

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

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

    name

    of the timer to cancel

    Definition Classes
    PersistentFSMBase
  6. implicit val context: ActorContext

    Scala API: Stores the context for this actor, including self, and sender.

    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!

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

    Definition Classes
    Actor
  7. def defer[A](event: A)(handler: (A) ⇒ Unit): Unit

    Defer the handler execution until all pending handlers have been executed.

    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.

    event

    event to be handled in the future, when preceding persist operations have been processes

    handler

    handler for the given event

    Definition Classes
    PersistentActor
  8. def deferAsync[A](event: A)(handler: (A) ⇒ Unit): Unit

    Defer the handler execution until all pending handlers have been executed.

    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.

    event

    event to be handled in the future, when preceding persist operations have been processes

    handler

    handler for the given event

    Definition Classes
    PersistentActor
  9. def deleteMessages(toSequenceNr: Long): Unit

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

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

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

    The given toSequenceNr must be less than or equal to Eventsourced#lastSequenceNr, otherwise 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.

    toSequenceNr

    upper sequence number (inclusive) bound of persistent messages to be deleted.

    Definition Classes
    Eventsourced
  10. def deleteSnapshot(sequenceNr: Long): Unit

    Deletes the snapshot identified by sequenceNr.

    Deletes the snapshot identified by sequenceNr.

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

    Definition Classes
    Snapshotter
  11. def deleteSnapshots(criteria: SnapshotSelectionCriteria): Unit

    Deletes all snapshots matching criteria.

    Deletes all snapshots matching criteria.

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

    Definition Classes
    Snapshotter
  12. val domainEventTag: ClassTag[E]

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

  13. final def goto(nextStateName: S): State

    Produce transition to other state.

    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.

    nextStateName

    state designator for the next state

    returns

    state transition descriptor

    Definition Classes
    PersistentFSMBase
  14. def internalStashOverflowStrategy: StashOverflowStrategy

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

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

    Definition Classes
    PersistenceStash
  15. final def isTimerActive(name: String): Boolean

    Inquire whether the named timer is still active.

    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.

    Definition Classes
    PersistentFSMBase
  16. def journalPluginId: String

    Configuration id of the journal plugin servicing this persistent actor.

    Configuration id of the journal plugin servicing this persistent actor. When empty, looks in akka.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.

    Definition Classes
    PersistenceIdentity
  17. def lastSequenceNr: Long

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

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

    Definition Classes
    Eventsourced
  18. def loadSnapshot(persistenceId: String, criteria: SnapshotSelectionCriteria, toSequenceNr: Long): Unit

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

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

    Definition Classes
    Snapshotter
  19. def log: LoggingAdapter
    Definition Classes
    ActorLogging
  20. final def nextStateData: D

    Return next state data (available in onTransition handlers)

    Return next state data (available in onTransition handlers)

    Definition Classes
    PersistentFSMBase
  21. def onRecoveryCompleted(): Unit

    Override this handler to define the action on recovery completion

  22. final def onTermination(terminationHandler: PartialFunction[StopEvent, Unit]): Unit

    Set handler which is called upon termination of this FSM actor.

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

    Definition Classes
    PersistentFSMBase
  23. final def onTransition(transitionHandler: TransitionHandler): Unit

    Set handler which is called upon each state transition, i.e.

    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.

    Definition Classes
    PersistentFSMBase
  24. def persist[A](event: A)(handler: (A) ⇒ Unit): Unit

    Asynchronously persists event.

    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.

    event

    event to be persisted

    handler

    handler for each persisted event

    Definition Classes
    PersistentActor
  25. def persistAll[A](events: Seq[A])(handler: (A) ⇒ Unit): Unit

    Asynchronously persists events in specified order.

    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.

    events

    events to be persisted

    handler

    handler for each persisted events

    Definition Classes
    PersistentActor
  26. def persistAllAsync[A](events: Seq[A])(handler: (A) ⇒ Unit): Unit

    Asynchronously persists events in specified order.

    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.

    events

    events to be persisted

    handler

    handler for each persisted events

    Definition Classes
    PersistentActor
  27. def persistAsync[A](event: A)(handler: (A) ⇒ Unit): Unit

    Asynchronously persists event.

    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.

    event

    event to be persisted

    handler

    handler for each persisted event

    Definition Classes
    PersistentActor
  28. def postRestart(reason: Throwable): Unit

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

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

    reason

    the Throwable that caused the restart to happen Is called right AFTER restart on the newly created Actor to allow reinitialization after an Actor crash.

    Definition Classes
    Actor
    Annotations
    @throws( classOf[Exception] )
  29. def postStop(): Unit

    Call onTermination hook; if you want to retain this behavior when overriding make sure to call super.postStop().

    Call onTermination hook; if you want to retain this behavior when overriding make sure to call super.postStop().

    Please note that this method is called by default from preRestart(), so override that one if onTermination shall not be called during restart.

    Definition Classes
    PersistentFSMBaseActor
  30. def preRestart(reason: Throwable, message: Option[Any]): Unit

    Overridden callback.

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

    reason

    the Throwable that caused the restart to happen

    message

    optionally the current message the actor processed when failing, if applicable Is called on a crashed Actor right BEFORE it is restarted to allow clean up of resources before Actor is terminated.

    Definition Classes
    UnrestrictedStashActor
  31. def preStart(): Unit

    User overridable callback.

    User overridable callback.

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

    Definition Classes
    Actor
    Annotations
    @throws( classOf[Exception] )
  32. def receive: Receive

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

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

    Definition Classes
    PersistentFSMBaseActor
  33. def receiveCommand: Receive

    After recovery events are handled as in usual FSM actor

    After recovery events are handled as in usual FSM actor

    Definition Classes
    PersistentFSM → Eventsourced
  34. def receiveRecover: Receive

    Discover the latest recorded state

    Discover the latest recorded state

    Definition Classes
    PersistentFSM → Eventsourced
  35. def recovery: Recovery

    Called when the persistent actor is started for the first time.

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

    To skip recovery completely return Recovery.none.

    Definition Classes
    PersistenceRecovery
  36. def recoveryFinished: Boolean

    Returns true if this persistent actor has successfully finished recovery.

    Returns true if this persistent actor has successfully finished recovery.

    Definition Classes
    Eventsourced
  37. def recoveryRunning: Boolean

    Returns true if this persistent actor is currently recovering.

    Returns true if this persistent actor is currently recovering.

    Definition Classes
    Eventsourced
  38. def saveSnapshot(snapshot: Any): Unit

    Saves a snapshot of this snapshotter's state.

    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.

    Definition Classes
    Snapshotter
  39. final def saveStateSnapshot(): Unit

    Save the current state as a snapshot

  40. implicit final val self: ActorRef

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

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

    Can be used to send messages to itself:

    self ! message
    

    Definition Classes
    Actor
  41. final def sender(): ActorRef

    The reference sender Actor of the last received message.

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

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

    Definition Classes
    Actor
  42. final def setStateTimeout(state: S, timeout: Timeout): Unit

    Set state timeout explicitly.

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

    Definition Classes
    PersistentFSMBase
  43. final def setTimer(name: String, msg: Any, timeout: FiniteDuration, repeat: Boolean = false): Unit

    Schedule named timer to deliver message after given delay, possibly repeating.

    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.

    name

    identifier to be used with cancelTimer()

    msg

    message to be delivered

    timeout

    delay of first message delivery and between subsequent messages

    repeat

    send once if false, scheduleAtFixedRate if true

    Definition Classes
    PersistentFSMBase
  44. def snapshotPluginId: String

    Configuration id of the snapshot plugin servicing this persistent actor.

    Configuration id of the snapshot plugin servicing this persistent actor. When empty, looks in akka.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.

    Definition Classes
    PersistenceIdentity
  45. def snapshotSequenceNr: Long

    Returns lastSequenceNr.

    Returns lastSequenceNr.

    Definition Classes
    Eventsourced → Snapshotter
  46. def snapshotterId: String

    Returns persistenceId.

    Returns persistenceId.

    Definition Classes
    Eventsourced → Snapshotter
  47. final def startWith(stateName: S, stateData: D, timeout: Timeout = None): Unit

    Set initial state.

    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 akka.actor.Actor#preStart and akka.actor.Actor#postRestart.

    stateName

    initial state designator

    stateData

    initial state data

    timeout

    state timeout for the initial state, overriding the default timeout for that state

    Definition Classes
    PersistentFSMBase
  48. def stash(): Unit

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

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

    Definition Classes
    Eventsourced → StashSupport
    Exceptions thrown

    IllegalStateException if the same message is stashed more than once

    StashOverflowException in case of a stash capacity violation

  49. final def stateData: D

    Return current state data (i.e.

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

    Definition Classes
    PersistentFSMBase
  50. final def stateName: S

    Return current state name (i.e.

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

    Definition Classes
    PersistentFSMBase
  51. lazy val statesMap: Map[String, S]

    Map from state identifier to state instance

  52. final def stay(): State

    Produce "empty" transition descriptor.

    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.

    returns

    descriptor for staying in current state

    Definition Classes
    PersistentFSMBase
  53. final def stop(reason: Reason, stateData: D): State

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

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

    Definition Classes
    PersistentFSMBase
  54. final def stop(reason: Reason): State

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

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

    Definition Classes
    PersistentFSMBase
  55. final def stop(): State

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

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

    Definition Classes
    PersistentFSMBase
  56. def supervisorStrategy: SupervisorStrategy

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

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

    Definition Classes
    Actor
  57. implicit final def total2pf(transitionHandler: (S, S) ⇒ Unit): TransitionHandler

    Convenience wrapper for using a total function instead of a partial function literal.

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

    Definition Classes
    PersistentFSMBase
  58. final def transform(func: StateFunction): TransformHelper
    Definition Classes
    PersistentFSMBase
  59. def unhandled(message: Any): Unit

    User overridable callback.

    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 akka.actor.DeathPactException (in case of an unhandled akka.actor.Terminated message) or publishes an akka.actor.UnhandledMessage to the actor's system's akka.event.EventStream

    Definition Classes
    Eventsourced → Actor
  60. def unstashAll(): Unit

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

    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().

    Definition Classes
    Eventsourced → StashSupport
  61. final def when(stateName: S, stateTimeout: FiniteDuration = null)(stateFunction: StateFunction): Unit

    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.

    stateName

    designator for the state

    stateTimeout

    default state timeout for this state

    stateFunction

    partial function describing response to input

    Definition Classes
    PersistentFSMBase
  62. final def whenUnhandled(stateFunction: StateFunction): Unit

    Set handler which is called upon reception of unhandled messages.

    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.

    Definition Classes
    PersistentFSMBase