/**
 * Statistics about the current cache state.
 */
export interface CacheStats {
    /** Number of cached entries */
    cacheSize: number;
    /** Number of pending fetch requests */
    pendingRequests: number;
    /** Array of all cache keys */
    keys: string[];
}
/**
 * Generic data cache with promise deduplication.
 *
 * Provides in-memory caching with automatic request deduplication to prevent
 * multiple simultaneous fetches for the same key.
 */
export declare class DataCache<T = any> {
    /** Map storing cached data by key */
    static cache: Map<string, any>;
    /** Map storing pending fetch promises by key */
    static promises: Map<string, Promise<any>>;
    /**
     * Gets data from cache or fetches if not cached.
     *
     * Automatically deduplicates concurrent requests for the same key.
     *
     * @param key - Cache key
     * @param fetcher - Function to fetch data if not cached
     * @returns Promise resolving to the cached or fetched data
     */
    static get<K>(key: string, fetcher: () => Promise<K>): Promise<K>;
    /**
     * Checks if a key exists in cache without fetching.
     *
     * @param key - Cache key to check
     * @returns True if key exists in cache
     */
    static has(key: string): boolean;
    /**
     * Gets cached data synchronously without fetching.
     *
     * @param key - Cache key
     * @returns Cached data or undefined if not cached
     */
    static peek<K>(key: string): K | undefined;
    /**
     * Removes a specific cache entry.
     *
     * @param key - Cache key to remove
     */
    static invalidate(key: string): void;
    /**
     * Clears all cached data and pending promises.
     */
    static clear(): void;
    /**
     * Sets data directly in cache without fetching.
     *
     * @param key - Cache key
     * @param data - Data to cache
     * @returns Promise resolving to the cached data
     */
    static set<K>(key: string, data: K): Promise<K>;
    /**
     * Gets cache statistics including size and pending requests.
     *
     * @returns Object with cache statistics
     */
    static stats(): CacheStats;
}
/**
 * Initializes and returns a new widget cache instance.
 *
 * @returns A new DataCache instance
 */
export declare function initWidgetCache(): DataCache<any>;