/**
 * DataSourceCache - TTL-based cache for TreeView lazy loading
 * Provides efficient caching with automatic expiration for tree data
 */
export declare class DataSourceCache {
    private cache;
    private defaultTTL;
    /**
     * Create a new DataSourceCache instance
     * @param defaultTTL Default time to live in milliseconds (default: 5 minutes)
     */
    constructor(defaultTTL?: number);
    /**
     * Set a value in the cache with optional TTL
     * @param key Cache key
     * @param value Value to cache
     * @param ttl Time to live in milliseconds (optional)
     */
    set<T>(key: string, value: T, ttl?: number): void;
    /**
     * Get a value from the cache
     * @param key Cache key
     * @returns Cached value or undefined if expired/not found
     */
    get<T>(key: string): T | undefined | -1;
    /**
     * Clear all cached data
     */
    clear(): void;
    /**
     * Delete a specific cache entry
     * @param key Cache key to delete
     */
    delete(key: string): void;
    /**
     * Get cache size
     * @returns Number of cached items
     */
    size(): number;
    /**
     * Set default TTL for future cache entries
     * @param ttl Time to live in milliseconds
     */
    setDefaultTTL(ttl: number): void;
}