import type { BackoffOptions, Deferred } from './types';
import type { JsMsg, Nanos } from 'nats';
export declare const nanos: (x: string) => number;
export declare const nanosToMs: (x: Nanos | undefined) => number;
/**
 * Given a starting backoff in ms, generate an array of doubling
 * values with at most `numEntries` and repeating after
 * `repeatAfter` entries.
 *
 * Note that `repeatAfter` defaults to `numEntries` and `numEntries`
 * defaults to 5.
 */
export declare const expBackoff: (startMs: number, options?: BackoffOptions) => number[];
export declare function defer<A>(): Deferred<A>;
/**
 * Get the next backoff based on the redelivery count. If given
 * an array and no item exists for the attempt number use the last
 * backoff in the array.
 */
export declare const getNextBackoff: (backoff: number | number[], msg: JsMsg) => number | undefined;
/**
 * Call fn on an interval.
 */
export declare const repeater: (fn: () => void, interval: number) => {
    start: () => void;
    stop: () => void;
};
/**
 * Calculate elapsed time in milliseconds.
 */
export declare const stopwatch: () => {
    start: () => void;
    stop: () => number;
};