import type { IEvent } from './IEvent.ts';
/**
 * Interface for tracking event processing state to prevent concurrent processing
 * by multiple processes.
 */
export interface IEventLocker {
    /**
     * Retrieves the last projected event,
     * allowing the projection state to be restored from subsequent events.
     */
    getLastEvent(): Promise<IEvent | undefined> | IEvent | undefined;
    /**
     * Marks an event as projecting to prevent it from being processed
     * by another projection instance using the same storage.
     *
     * @returns `false` if the event is already being processed or has been processed.
     */
    tryMarkAsProjecting(event: IEvent): Promise<boolean> | boolean;
    /**
     * Marks an event as projected.
     */
    markAsProjected(event: IEvent): Promise<void> | void;
    /**
     * Records an event as the last projected event (restore checkpoint).
     */
    markAsLastEvent(event: IEvent): Promise<void> | void;
}
export declare const isEventLocker: (view: unknown) => view is IEventLocker;