EventManager

Manage events and their listeners, enabling registration, emission, and execution control.

Listeners can be registered for any of the events and are invoked whenever the event is emitted, each of them in its own task - the sync ones in a separate thread so that they cannot block the event loop. On top of that, it emits PersistState events at regular intervals and can wait for all the running listeners to complete.

Hierarchy

• EventManager
  • LocalEventManager

Index

Methods

• __aenter__
• __aexit__
• __init__
• emit
• off
• on
• wait_for_all_listeners_to_complete

Properties

• active

Methods

__aenter__

• async __aenter__(): Self

• Initialize the event manager upon entering the async context.

  ---

  Returns Self

__aexit__

• async __aexit__(exc_type, exc_value, exc_traceback): None

• Close the event manager upon exiting the async context.

  This will stop listening for the events, and it will wait for all the event listeners to finish.

  ---

  Parameters

  • exc_type: type[BaseException] | None

  • exc_value: BaseException | None

  • exc_traceback: TracebackType | None

  Returns None

__init__

• __init__(*, persist_state_interval, close_timeout): None

• Initialize a new instance.

  ---

  Parameters

  • optionalkeyword-onlypersist_state_interval: timedelta = timedelta(minutes=1)

    Interval between emitted PersistState events to maintain state persistence.

  • optionalkeyword-onlyclose_timeout: timedelta | None = None

    Optional timeout for canceling pending event listeners if they exceed this duration.

  Returns None

emit

• emit(*: , event: Event, event_data: EventData): None
• emit(*: , event: Literal[Event.PERSIST_STATE], event_data: EventPersistStateData): None
• emit(*: , event: Literal[Event.SYSTEM_INFO], event_data: EventSystemInfoData): None
• emit(*: , event: Literal[Event.MIGRATING], event_data: EventMigratingData): None
• emit(*: , event: Literal[Event.ABORTING], event_data: EventAbortingData): None
• emit(*: , event: Literal[Event.EXIT], event_data: EventExitData): None
• emit(*: , event: Literal[Event.CRAWLER_STATUS], event_data: EventCrawlerStatusData): None
• emit(*: , event: Event, event_data: Any): None

• Emit an event with the associated data to all registered listeners.

  Each listener is invoked in its own task, so this method only starts them. Use wait_for_all_listeners_to_complete to wait for them to finish.

  ---

  Parameters

  • keyword-onlyevent: Event

    The event which will be emitted.

  • keyword-onlyevent_data: EventData

    The data which will be passed to the event listeners.

  Returns None

off

• off(*, event, listener): None

• Remove a specific listener or all listeners for an event.

  ---

  Parameters

  • keyword-onlyevent: Event

    The Actor event for which to remove listeners.

  • optionalkeyword-onlylistener: EventListener[Any] | None = None

    The listener which is supposed to be removed. If not passed, all listeners of this event are removed.

  Returns None

on

• on(*: , event: Event, listener: EventListener[Any]): None
• on(*: , event: Literal[Event.PERSIST_STATE], listener: EventListener[EventPersistStateData]): None
• on(*: , event: Literal[Event.SYSTEM_INFO], listener: EventListener[EventSystemInfoData]): None
• on(*: , event: Literal[Event.MIGRATING], listener: EventListener[EventMigratingData]): None
• on(*: , event: Literal[Event.ABORTING], listener: EventListener[EventAbortingData]): None
• on(*: , event: Literal[Event.EXIT], listener: EventListener[EventExitData]): None
• on(*: , event: Literal[Event.CRAWLER_STATUS], listener: EventListener[EventCrawlerStatusData]): None
• on(*: , event: Event, listener: EventListener[None]): None

• Register an event listener for a specific event.

  ---

  Parameters

  • keyword-onlyevent: Event

    The event for which to listen to.

  • keyword-onlylistener: EventListener[Any]

    The function (sync or async) which is to be called when the event is emitted.

  Returns None

wait_for_all_listeners_to_complete

• async wait_for_all_listeners_to_complete(*, timeout): None

• Wait for all currently executing event listeners to complete.

  ---

  Parameters

  • optionalkeyword-onlytimeout: timedelta | None = None

    The maximum time to wait for the event listeners to finish. If they do not complete within the specified timeout, they will be canceled.

  Returns None

Properties

active

active: bool

Indicate whether the context is active.