/**
 * Completion Cache
 *
 * A simple in-memory cache with TTL support for completion data.
 */
export declare class CompletionCache {
    private cache;
    private ttl;
    /**
     * Create a new completion cache
     * @param ttl Time-to-live in milliseconds (default: 60000 = 1 minute)
     */
    constructor(ttl?: number);
    /**
     * Get a cached value or load it using the provided loader function
     * @param key Cache key
     * @param loader Async function to load the value if not cached
     * @returns Cached or newly loaded value
     */
    getOrLoad<T>(key: string, loader: () => Promise<T>): Promise<T>;
    /**
     * Get a cached value synchronously (returns undefined if not cached or expired)
     * @param key Cache key
     * @returns Cached value or undefined
     */
    get<T>(key: string): T | undefined;
    /**
     * Set a cached value
     * @param key Cache key
     * @param value Value to cache
     * @param customTtl Optional custom TTL for this entry
     */
    set<T>(key: string, value: T, customTtl?: number): void;
    /**
     * Check if a key exists and is not expired
     * @param key Cache key
     * @returns Whether the key exists and is valid
     */
    has(key: string): boolean;
    /**
     * Invalidate cache entries matching a pattern
     * @param pattern Optional pattern to match keys (if not provided, clears all)
     */
    invalidate(pattern?: string): void;
    /**
     * Get the number of entries in the cache (including expired ones)
     */
    get size(): number;
    /**
     * Clear all expired entries
     * @returns Number of entries removed
     */
    cleanup(): number;
}