RecipientBehaviour overview

Added in v1.0.0

Table of contents

• models
  • RecipientBehaviour (interface)
• utils
  • EntityBehaviourOptions (type alias)
  • fromFunctionEffect
  • fromFunctionEffectStateful
  • fromInMemoryQueue

models

RecipientBehaviour (interface)

A RecipientBehaviour describes how a specific RecipientType should behave. This is the actual implementation of what an entity should do upon receiving a Msg, this could require additional context.

The scope provided in the context is controlled by the cluster EntityManager, and is used to request the shoutdown of the entity, so you can safely scope whatever resource you want to use for your behaviour and the EntityManager will close the scope for you when the entity is shoutdown.

The function returned by the RecipientBehaviour effect is what we call “offer” effect. The offer effect is used by the EntityManager to give messages to the RecipientBehaviour.

Signature

export interface RecipientBehaviour<Msg, R>
  extends Effect.Effect<
    <A extends Msg>(
      message: A
    ) => Effect.Effect<
      MessageState.MessageState<Message.Message.Exit<A>>,
      ShardingException.ExceptionWhileOfferingMessageException
    >,
    never,
    R | RecipientBehaviourContext.RecipientBehaviourContext | Scope.Scope
  > {}

Added in v1.0.0

utils

EntityBehaviourOptions (type alias)

This are the options for an EntityBehaviour. This controls the entityMaxIdleTime, check out more on that over the ShardingConfig. This allows to override the setting for a specific entity.

Signature

export type EntityBehaviourOptions = {
  entityMaxIdleTime?: Option.Option<Duration.Duration>
}

Added in v1.0.0

fromFunctionEffect

This is the simplest behaviour you can have. You provide a function that given the entityId and the message, it will immediatly process it. You are then required to return a MessageState to tell the caller if the message has just arrived and will be later processed or it has been processed.

Signature

export declare const fromFunctionEffect: <Msg extends Message.Message.Any, R>(
  handler: (
    entityId: string,
    message: Msg
  ) => Effect.Effect<MessageState.MessageState<Message.Message.Exit<Msg>>, never, R>
) => RecipientBehaviour<Msg, R>

Added in v1.0.0

fromFunctionEffectStateful

This is a stateful version of fromFunctionEffect. You can provide a function to get the initialState, and then it will be passed as Ref. Everything here is just stored in memory, so eventual persistence of the state is up to you!

Signature

export declare const fromFunctionEffectStateful: <S, R, Msg extends Message.Message.Any, R2>(
  initialState: (entityId: string) => Effect.Effect<S, never, R>,
  handler: (
    entityId: string,
    message: Msg,
    stateRef: Ref.Ref<S>
  ) => Effect.Effect<MessageState.MessageState<Message.Message.Exit<Msg>>, never, R2>
) => RecipientBehaviour<Msg, R | R2>

Added in v1.0.0

fromInMemoryQueue

This behaviour uses a Queue where the entity will accumulate messages to be processed, and then you can use the Dequeue to take messages and process them. A PoisonPill is provided to request interruption of the entity behaviour.

Signature

export declare const fromInMemoryQueue: <Msg extends Message.Message.Any, R>(
  handler: (
    entityId: string,
    dequeue: Queue.Dequeue<Msg | PoisonPill.PoisonPill>,
    processed: <A extends Msg>(
      message: A,
      value: Option.Option<Message.Message.Exit<A>>
    ) => Effect.Effect<void, never, never>
  ) => Effect.Effect<void, never, R>
) => RecipientBehaviour<Msg, R>

Added in v1.0.0