/// <reference types="express-session" />
import { Store } from 'express-session';
import { Etcd3, IOptions } from 'etcd3';
/**
 * One day in seconds.
 */
export declare const oneDay = 86400;
/**
 * Max TTL time to leasing on ETCD3 Client in seconds.
 */
export declare const maxTTL = 6442450;
/**
 * Configuration options for the etcd v3
 */
export interface Etcd3StoreOptions extends IOptions {
    /**
     * Prefix used to record the keys of all the sessions.
     *
     * Defaults to `sess`.
     */
    prefix?: string;
    /**
     * Option to skip touching process that express does every time it reads the session.
     * This is useful if you work with big TTL and wanna free your ETCD from this extra access.
     *
     * Defaults to `false`.
     */
    skipTouch?: boolean;
}
/**
 * Default configuration values for the etcd v3 options
 */
export declare const defaultOptions: Etcd3StoreOptions;
/**
 * An etcd v3 store adapter for Express session using [etcd3](https://github.com/mixer/etcd3) client.
 *
 * ```
 * var session = require('express-session');
 * var Etcd3Store = require('express-session-etcd3');
 *
 * app.use(session({
 *     store: new Etcd3Store(options),
 *     secret: 'keyboard cat',
 *     resave: false
 * }));
 * ```
 */
export default class Etcd3Store extends Store {
    private config;
    private client;
    private debug;
    constructor(config?: Etcd3StoreOptions, client?: Etcd3);
    /**
     * This method is used to get a session from the store given a session
     * ID (`sid`). The `callback` should be called as `callback(error, session)`.
     *
     * The `session` argument should be a session if found, otherwise `null` or
     * `undefined` if the session was not found (and there was no error). A special
     * case is made when `error.code === 'ENOENT'` to act like `callback(null, null)`.
     */
    get: (sid: string, callback: (err: any, session: Express.SessionData) => void) => void;
    /**
     * This required method is used to upsert a session into the store given a
     * session ID (`sid`) and session (`session`) object. The callback should be
     * called as `callback(error)` once the session has been set in the store.
     */
    set: (sid: string, session: Express.SessionData, callback: (err: any) => void) => void;
    /**
     * This method is used to "touch" a given session given a
     * session ID (`sid`) and session (`session`) object. The `callback` should be
     * called as `callback(error)` once the session has been touched.
     *
     * This is primarily used when the store will automatically delete idle sessions
     * and this method is used to signal to the store the given session is active,
     * potentially resetting the idle timer.
     */
    touch: (sid: string, session: Express.SessionData, callback: (err: any) => void) => void;
    /**
     * This method is used to get all sessions in the store as an array. The
     * `callback` should be called as `callback(error, sessions)`.
     */
    all: (callback: (err: any, obj: {
        [sid: string]: Express.SessionData;
    }) => void) => void;
    /**
     * This method is used to get the count of all sessions in the store.
     * The `callback` should be called as `callback(error, len)`.
     */
    length: (callback: (err: any, length: number) => void) => void;
    /**
     * This method is used to destroy/delete a session from the store given
     * a session ID (`sid`). The `callback` should be called as `callback(error)`
     * once the session is destroyed.
     */
    destroy: (sid: string, callback: (err: any) => void) => void;
    /**
     * This method is used to delete all sessions from the store. The `callback`
     * should be called as `callback(error)` once the store is cleared.
     */
    clear: (callback: (err: any) => void) => void;
    /**
     * Build the etcd key with the right prefix and the givin session ID (`sid`)
     */
    private key(sid?);
    /**
     * Get the Time to Live (`ttl`) of the session
     */
    private getTTL(sess, sid);
    /**
     * Get the raw Time to Live (`ttl`) of the session from the data sources
     */
    private getRawTTL(sess, sid);
    /**
     * Logging callback result
     */
    private callbackWithLog(cb, err?, value?);
}