import { Gaddag } from '@kamilmielnik/gaddag';
import { type Locale } from '@scrabble-solver/types';
import type { Cache } from '../types';
export declare class DiskCache implements Cache<Locale, Gaddag> {
    private readonly directory;
    constructor(directory?: string);
    /**
     * Returns undefined when the cached file cannot be deserialized (it was
     * written by an app version with an incompatible format, or it is corrupted)
     * so that callers re-download and re-serialize the dictionary.
     */
    get(locale: Locale): Promise<Gaddag | undefined>;
    getLastModifiedTimestamp(locale: Locale): number | undefined;
    has(locale: Locale): boolean;
    isStale(locale: Locale): boolean | undefined;
    set(locale: Locale, gaddag: Gaddag): Promise<void>;
}