/// <reference types="node" />
import { Unit } from './lua';
export type SendCommand = (...args: any[]) => any;
export type Call = (command: string, args: (string | Buffer | number)[]) => any;
export interface RedisClientWrapper {
    sendCommand?: SendCommand;
    call?: Call;
}
export interface RateLimiterOptionsWindow {
    /**
     * Window unit (second, minute, hour, etc)
     */
    unit: Unit;
    /**
     * Window size in number of units (eg 1 second, 10 minutes, 2 hour, etc)
     */
    size: number;
    /**
     * Specify the granularity of the window, i.e. with which precision elements would expire in the current window.
     * Must be less or equal than window unit.
     */
    subdivisionUnit?: Unit;
}
export interface RateLimiterOptions {
    /**
     * Client object from any of the following libraries:
     * - https://www.npmjs.com/package/redis
     * - https://www.npmjs.com/package/ioredis
     */
    client: RedisClientWrapper;
    /**
     * Rate limiter window properties
     */
    window: RateLimiterOptionsWindow;
    /**
     * Number of requests allowed in the window (eg 10 requests per 1 second)
     */
    limit: number;
    /**
     * How many requests are allowed to exceed the limit expressed as a fraction of the limit, rounded down.
     * Example: with limit=10 and limitOverheadFraction=0.1, 10% of the requests (1) will be allowed to exceed the limit.
     * Default is zero.
     */
    limitOverhead?: number;
    /**
     * Optional name for this limiter
     */
    name?: string;
}
export interface RateLimiterResponse {
    /**
     * Number of remaining requests that can be performed in the current window
     */
    remaining: number;
    /**
     * Whether the request is allowed or not
     */
    allowed: boolean;
    /**
     * Epoch (milliseconds) at which the first element will expire in the current window
     */
    firstExpireAtMs: number;
    /**
     * Epoch (milliseconds) at which the current window will expire
     */
    windowExpireAtMs: number;
}
export declare class RateLimiter {
    private _strategy;
    private _tag;
    private _client;
    private _windowUnit;
    private _windowSize;
    private _windowSubdivisionUnit;
    private _limit;
    private _limitOverheadFraction;
    private _limitOverhead;
    private _window;
    private _windowExpireMs;
    private _name;
    constructor(options: RateLimiterOptions);
    private _updateWindow;
    private _updateWindowExpiration;
    get client(): RedisClientWrapper;
    set client(v: RedisClientWrapper);
    get windowUnit(): Unit;
    set windowUnit(v: Unit);
    get windowSize(): number;
    set windowSize(v: number);
    get windowSubdivisionUnit(): Unit;
    set windowSubdivisionUnit(v: Unit);
    get limit(): number;
    set limit(v: number);
    get limitOverheadFraction(): number;
    set limitOverheadFraction(v: number);
    get limitOverhead(): number;
    get window(): number;
    get windowExpireMs(): number;
    get name(): string;
    set name(v: string);
    toString(): string;
    get: (key: any) => Promise<RateLimiterResponse>;
}