import type { Redis, Cluster, Result } from 'ioredis';
export interface Config {
    timeout: number;
    retries: number;
    delay: number;
    jitter: number;
}
declare module 'ioredis' {
    interface RedisCommander<Context> {
        delifequal(key: string, id: string): Result<string, Context>;
        pexpireifequal(key: string, id: string, seconds: number): Result<string, Context>;
    }
}
/**
 * @class Lock
 */
export declare class Lock {
    static _acquiredLocks: Set<Lock>;
    private readonly _id;
    private readonly _client;
    private _locked;
    private _key;
    readonly config: Config;
    /**
     * The constructor for a Lock object. Accepts both a redis client, as well as
     * an options object with the following properties: timeout, retries and delay.
     * Any options not supplied are subject to the current defaults.
     * @constructor
     *
     * @param {RedisClient} client  The node_redis client to use
     * @param {object}      options
     *
     * @property {int} timeout Time in milliseconds before which a lock expires
     *                         (default: 10000 ms)
     * @property {int} retries Maximum number of retries in acquiring a lock if the
     *                         first attempt failed (default: 0)
     * @property {int} delay   Time in milliseconds to wait between each attempt
     *                         (default: 50 ms)
     */
    constructor(client: Redis | Cluster, options?: Partial<Config>);
    /**
     * Attempts to acquire a lock, given a key, and an optional callback function.
     * If the initial lock fails, additional attempts will be made for the
     * configured number of retries, and padded by the delay. The callback is
     * invoked with an error on failure, and returns a promise if no callback is
     * supplied. If invoked in the context of a promise, it may throw a
     * LockAcquisitionError.
     *
     * @param key The redis key to use for the lock
     */
    acquire(key: string): Promise<Lock>;
    /**
     * Attempts to extend the lock
     * @param expire in `timeout` seconds
     */
    extend(time?: number): Promise<Lock>;
    /**
     * Attempts to release the lock, and accepts an optional callback function.
     * The callback is invoked with an error on failure, and returns a promise
     * if no callback is supplied. If invoked in the context of a promise, it may
     * throw a LockReleaseError.
     */
    release(): Promise<Lock>;
    /**
     * @private
     */
    private _setupClient;
    /**
     * Attempts to acquire the lock, and retries upon failure if the number of
     * remaining retries is greater than zero. Each attempt is padded by the
     * lock's configured retry delay.
     *
     * @param {string} key     The redis key to use for the lock
     * @param {int}    retries Number of remaining retries
     *
     * @returns {Promise}
     */
    _attemptLock(key: string, retries: number): Promise<void>;
}