import { KVStorage as KVStorageInterface, VALUE } from './interface';
declare type DriverNames = 'sqlite' | 'indexeddb' | 'leveldatastore' | 'websql' | 'localstorage';
declare type PickRequired<T, K extends keyof T> = {
    [P in K]-?: T[P];
};
export interface KVStorageConfig {
    /**
     * The name of the database.
     * May appear during storage limit prompts.
     * Useful to use the name of your app here.
     * In localStorage, this is used as a key prefix for all keys stored in localStorage and level-datastore.
     * Must be alphanumeric, with underscores.
     */
    name?: string;
    version?: number;
    /**
     * The size of the database in bytes.
     * Used only in WebSQL for now.
     */
    size?: number;
    /**
     * The name of the datastore.
     * In IndexedDB this is the dataStore,
     * in WebSQL this is the name of the key/value table in the database,
     * Must be alphanumeric, with underscores. Any non-alphanumeric characters will be converted to underscores.
     */
    storeName?: string;
    description?: string;
    driverOrder?: DriverNames[];
    /**
     * similar to `name`.
     * Used only in CordovaSQLiteDriver.
     */
    dbKey?: string;
    /**
     * Used only in localforage-driver-datastore-level
     */
    path?: string;
}
export declare const getDefaultConfig: () => PickRequired<KVStorageConfig, "path" | "name" | "storeName" | "dbKey" | "driverOrder">;
/**
 * Preference (key-value) Storage,
 * work in both Browser, Node.js, and Cordova/Ionic
 *
 * Modified from https://github.com/ionic-team/ionic-storage/blob/master/src/storage.ts
 */
export declare class KVStorage implements KVStorageInterface {
    private _db;
    private _driver;
    readonly backend = "localforage";
    constructor(config?: KVStorageConfig);
    ready(): Promise<void>;
    close(): Promise<void>;
    /**
     * Get the name of the driver being used.
     */
    get driver(): string | null;
    private _getDrivers;
    has(key: string): Promise<boolean>;
    /**
     * Get the value associated with the given key.
     * @param key the key to identify this value
     * @returns Returns a promise with the value of the given key
     */
    get(key: string): Promise<VALUE>;
    /**
     * Set the value for the given key.
     * @param key the key to identify this value
     * @param value the value for this key
     * @returns Returns a promise that resolves when the key and value are set
     */
    set<T extends VALUE>(key: string, value: T): Promise<T>;
    /**
     * Remove any value associated with this key.
     * @param key the key to identify this value
     * @returns Returns a promise that resolves when the value is removed
     */
    remove(key: string): Promise<any>;
    /**
     * Clear the entire key value store. WARNING: HOT!
     * @returns Returns a promise that resolves when the store is cleared
     */
    clear(): Promise<void>;
    /**
     * @returns Returns a promise that resolves with the number of keys stored.
     */
    length(): Promise<number>;
    /**
     * @returns Returns a promise that resolves with the keys in the store.
     */
    keys(): Promise<string[]>;
    /**
     * Iterate through each key,value pair.
     * @param iteratorCallback a callback of the form (value, key, iterationNumber)
     * @returns Returns a promise that resolves when the iteration has finished.
     */
    forEach(iteratorCallback: (value: any, key: string, iterationNumber: Number) => any): Promise<void>;
}
export default KVStorage;