import { Cache } from '../Cache';
import { KeyType } from '../KeyType';
import { Loader } from './Loader';
/**
 * Cache that also supports loading of data if it's not in the cache.
 */
export interface LoadingCache<K extends KeyType, V> extends Cache<K, V> {
    /**
     * Get cached value or load it if not currently cached. Updates the usage
     * of the key.
     *
     * @param key -
     *   key to get
     * @param loader -
     *   optional loader to use for loading the object
     * @returns
     *   promise that resolves to the loaded value
     */
    get(key: K, loader?: Loader<K, V>): Promise<V>;
}