EventsourcedView

An actor that derives internal state from events stored in an event log. Events are pushed from the eventLog actor to this actor and handled with the onEvent event handler. An event handler defines how internal state is updated from events.

An EventsourcedView can also store snapshots of internal state with its save method. During (re-)start the latest snapshot saved by this actor (if any) is passed as argument to the onSnapshot handler, if the handler is defined at that snapshot. If the onSnapshot handler is not defined at that snapshot or is not overridden at all, event replay starts from scratch. Newer events that are not covered by the snapshot are handled by onEvent after onSnapshot returns.

By default, an EventsourcedView does not define an aggregateId. In this case, the eventLog pushes all events to this actor. If it defines an aggregateId, the eventLog actor only pushes those events that contain that aggregateId value in their routingDestinations set.

An EventsourcedView can only consume events from its eventLog but cannot produce new events. Commands sent to an EventsourcedView during recovery are delayed until recovery completes.

See also: DurableEvent
EventsourcedActor

Linear Supertypes

ActorLogging, InternalStash, StashFactory, Stash, RequiresMessageQueue[DequeBasedMessageQueueSemantics], UnrestrictedStash, StashSupport, ConditionalCommands, Actor, AnyRef, Any

Known Subclasses

AbstractEventsourcedActor, AbstractEventsourcedView, ConfirmedDelivery, EventsourcedActor

Type Members

type Handler[A] = (Try[A]) ⇒ Unit
type Receive = PartialFunction[Any, Unit]

Definition Classes
Actor

Abstract Value Members

abstract def eventLog: ActorRef

Event log actor.
abstract def id: String

Global unique actor id.
abstract def onCommand: Receive

Command handler.
abstract def onEvent: Receive

Event handler.

Concrete Value Members

final def !=(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def ##(): Int

Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def aggregateId: Option[String]

Optional aggregate id.
Optional aggregate id. It is used for routing DurableEvents to event-sourced destinations which can be EventsourcedViews or EventsourcedActors. By default, an event is routed to an event-sourced destination with an undefined aggregateId. If a destination's aggregateId is defined it will only receive events with a matching aggregate id in DurableEvent#destinationAggregateIds.
def aroundPostRestart(reason: Throwable): Unit

Attributes
protected[akka]
Definition Classes
Actor
def aroundPostStop(): Unit

Attributes
protected[akka]
Definition Classes
Actor
def aroundPreRestart(reason: Throwable, message: Option[Any]): Unit

Attributes
protected[akka]
Definition Classes
Actor
def aroundPreStart(): Unit

Attributes
protected[akka]
Definition Classes
Actor
def aroundReceive(receive: akka.actor.Actor.Receive, msg: Any): Unit

Attributes
protected[akka]
Definition Classes
Actor
final def asInstanceOf[T0]: T0

Definition Classes
Any
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
implicit val context: ActorContext

Definition Classes
Actor
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
def hashCode(): Int

Definition Classes
AnyRef → Any
val instanceId: Int
def internalStash(): Unit

Internal API.
Internal API.

Definition Classes
InternalStash
def internalUnstash(): Unit

Internal API.
Internal API.

Definition Classes
InternalStash
def internalUnstashAll(): Unit

Internal API.
Internal API.

Definition Classes
InternalStash
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
final def lastEmitterAggregateId: Option[String]

Emitter aggregate id of the last handled event.
final def lastEmitterId: String

Emitter id of the last handled event.
final def lastSequenceNr: Long

Sequence number of the last handled event.
final def lastSystemTimestamp: Long

Wall-clock timestamp of the last handled event.
final def lastVectorTimestamp: VectorTime

Vector timestamp of the last handled event.
def load(): Unit

Sends a LoadSnapshot command to the event log.
Sends a LoadSnapshot command to the event log. Can be overridden by implementations to customize snapshot loading.
def log: LoggingAdapter

Definition Classes
ActorLogging
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
def onRecovered(): Unit

Called after recovery successfully completed.
Called after recovery successfully completed. Can be overridden by implementations.
def onSnapshot: Receive

Snapshot handler.
def postRestart(reason: Throwable): Unit

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

Definition Classes
InternalStash → UnrestrictedStash → Actor
def preRestart(reason: Throwable, message: Option[Any]): Unit

Definition Classes
InternalStash → UnrestrictedStash → Actor
def preStart(): Unit

Initiates recovery by calling load.
Initiates recovery by calling load.

Definition Classes
EventsourcedView → Actor
final def receive: Receive

Initialization behavior.
Initialization behavior.

Definition Classes
EventsourcedView → Actor
final def recovering: Boolean

Returns true if this actor is currently recovering internal state by consuming replayed events from the event log.
Returns true if this actor is currently recovering internal state by consuming replayed events from the event log. Returns false after recovery completed and the actor switches to consuming live events.
def replay(fromSequenceNr: Long = 1L): Unit

Sends a Replay command to the event log.
Sends a Replay command to the event log. Can be overridden by implementations to customize replay.
def save(snapshot: Any)(handler: Handler[SnapshotMetadata]): Unit

Asynchronously saves the given snapshot and calls handler with the generated snapshot metadata.
Asynchronously saves the given snapshot and calls handler with the generated snapshot metadata. The handler can also obtain a reference to the initial message sender via sender().
implicit final val self: ActorRef

Definition Classes
Actor
final def sender(): ActorRef

Definition Classes
Actor
def stash(): Unit

Definition Classes
StashSupport
def supervisorStrategy: SupervisorStrategy

Definition Classes
Actor
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def toString(): String

Definition Classes
AnyRef → Any
def unhandled(message: Any): Unit

Definition Classes
Actor
def unstashAll(): Unit

Definition Classes
StashSupport
final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

trait EventsourcedView extends Actor with ConditionalCommands with InternalStash with ActorLogging

Type Members

type Handler[A] = (Try[A]) ⇒ Unit

type Receive = PartialFunction[Any, Unit]

Abstract Value Members

abstract def eventLog: ActorRef

abstract def id: String

abstract def onCommand: Receive

abstract def onEvent: Receive

Concrete Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

def aggregateId: Option[String]

def aroundPostRestart(reason: Throwable): Unit

def aroundPostStop(): Unit

def aroundPreRestart(reason: Throwable, message: Option[Any]): Unit

def aroundPreStart(): Unit

def aroundReceive(receive: akka.actor.Actor.Receive, msg: Any): Unit

final def asInstanceOf[T0]: T0

def clone(): AnyRef

implicit val context: ActorContext

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

final def getClass(): Class[_]

def hashCode(): Int

val instanceId: Int

def internalStash(): Unit

def internalUnstash(): Unit

def internalUnstashAll(): Unit

final def isInstanceOf[T0]: Boolean

final def lastEmitterAggregateId: Option[String]

final def lastEmitterId: String

final def lastSequenceNr: Long

final def lastSystemTimestamp: Long

final def lastVectorTimestamp: VectorTime

def load(): Unit

def log: LoggingAdapter

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

def onRecovered(): Unit

def onSnapshot: Receive

def postRestart(reason: Throwable): Unit

def postStop(): Unit

def preRestart(reason: Throwable, message: Option[Any]): Unit

def preStart(): Unit

final def receive: Receive

final def recovering: Boolean

def replay(fromSequenceNr: Long = 1L): Unit

def save(snapshot: Any)(handler: Handler[SnapshotMetadata]): Unit

implicit final val self: ActorRef

final def sender(): ActorRef

def stash(): Unit

def supervisorStrategy: SupervisorStrategy

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

def unhandled(message: Any): Unit

def unstashAll(): Unit

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Inherited from ActorLogging

Inherited from InternalStash

Inherited from StashFactory

Inherited from Stash

Inherited from RequiresMessageQueue[DequeBasedMessageQueueSemantics]

Inherited from UnrestrictedStash

Inherited from StashSupport

Inherited from ConditionalCommands

Inherited from Actor

Inherited from AnyRef

Inherited from Any

Ungrouped