/// <reference types="node" />
import { Worker as Thread } from 'worker_threads';
import { Task } from './task';
export declare enum WorkerState {
    STARTING = 0,
    FREE = 1,
    RESERVED = 2,
    WORKING = 3,
    EXHAUSTED = 4
}
export interface WorkerSpawnData {
    queueName: string;
}
export interface WorkerOptions {
    queueName: string;
    entry: string;
}
/**
 * Messages sent from main thread
 */
export declare enum ParentMessageTypes {
    START_TASK = "START_TASK"
}
/**
 * Message interface from main thread
 */
export interface ParentMessage {
    type: ParentMessageTypes;
    data?: any;
}
export declare class Worker<TIn, TOut> {
    state: WorkerState;
    protected thread: Thread;
    protected id: number;
    protected task: Task<TIn, TOut>;
    /**
     * Spawn a thread for this worker
     *
     * Runs on: Main
     *
     * @param options Worker options
     * @returns Returns the worker
     */
    spawn(options: WorkerOptions): Promise<Worker<TIn, TOut>>;
    /**
     * Push a task to the worker
     *
     * Runs on: Main
     *
     * @param task Task to push
     */
    startTask(task: Task<TIn, TOut>): void;
    /**
     * Runs when the worker completes a task
     *
     * Runs on: Main
     *
     * @param response Response from the worker for this task
     */
    protected finished(response?: TOut): void;
    /**
     * Runs when the worker fails to complete a task
     *
     * Runs on: Main
     *
     * @param error Response from the worker
     */
    protected failed(error?: Error): void;
    /**
     * Runs when the worker errors or exits unexpectedly
     *
     * Runs on: Main
     *
     * @param error Error returned by the worker
     */
    protected exhausted(error?: Error): void;
}