import type { MachineMemoryRecord } from '../ArvoOrchestrator/types';
import type { IMachineMemory } from './interface';
/**
 * In-memory implementation of machine state storage for single-instance NodeJS apps.
 *
 * Best for: Container apps, request-scoped workflows, testing, demos
 * Not for: Multi-instance deployments, persistent workflows, distributed systems
 *
 * @example
 * const memory = new SimpleMachineMemory();
 * const orchestrator = createArvoOrchestrator({
 *   memory,
 *   executionunits: 1,
 *   machines: [workflow]
 * });
 */
export declare class SimpleMachineMemory implements IMachineMemory<MachineMemoryRecord> {
    private readonly memoryMap;
    private readonly lockMap;
    /**
     * Gets stored state for a machine instance
     * @param id Machine instance ID
     * @returns State data or null if not found
     * @throws {Error} When id is empty or undefined
     */
    read(id: string): Promise<MachineMemoryRecord | null>;
    /**
     * Stores state for a machine instance
     * @param id Machine instance ID
     * @param data State to store
     * @throws {Error} When id is empty/undefined or data is null/undefined
     */
    write(id: string, data: MachineMemoryRecord): Promise<void>;
    /**
     * Attempts to acquire lock for machine instance
     * @param id Machine instance ID
     * @returns Success status of lock acquisition
     * @throws {Error} When id is empty or undefined
     */
    lock(id: string): Promise<boolean>;
    /**
     * Releases lock for machine instance
     * @param id Machine instance ID
     * @returns True when lock is released
     * @throws {Error} When id is empty or undefined
     */
    unlock(id: string): Promise<boolean>;
    /**
     * Clears all stored data and locks
     */
    clear(key?: string): void;
}