/**
 * LRU Cache with TTL for Delphi Web Search
 *
 * Provides caching for web search results and page fetches
 * to avoid duplicate API calls and improve performance.
 */
/**
 * A generic LRU (Least Recently Used) cache with time-to-live (TTL) expiration.
 * - Entries expire after the TTL period
 * - When max size is reached, least recently used entries are evicted
 */
export declare class LRUCache<T> {
    private cache;
    private readonly maxSize;
    private readonly defaultTTL;
    private hits;
    private misses;
    /**
     * Create a new LRU cache.
     * @param maxSize Maximum number of entries (default 100)
     * @param defaultTTLMs Default time-to-live in milliseconds (default 24 hours)
     */
    constructor(maxSize?: number, defaultTTLMs?: number);
    /**
     * Get a value from the cache.
     * Returns undefined if not found or expired.
     * Accessing a key moves it to the "most recently used" position.
     */
    get(key: string): T | undefined;
    /**
     * Set a value in the cache.
     * If cache is full, the least recently used entry is evicted.
     * @param key Cache key
     * @param value Value to cache
     * @param ttlMs Optional TTL override in milliseconds
     */
    set(key: string, value: T, ttlMs?: number): void;
    /**
     * Check if a key exists and is not expired.
     */
    has(key: string): boolean;
    /**
     * Delete a key from the cache.
     */
    delete(key: string): boolean;
    /**
     * Clear all entries from the cache.
     */
    clear(): void;
    /**
     * Get cache statistics.
     */
    stats(): {
        size: number;
        maxSize: number;
        hits: number;
        misses: number;
        hitRate: number;
    };
    /**
     * Clean up expired entries.
     * Call this periodically to free memory from expired entries.
     */
    cleanup(): number;
}
export declare const searchCache: LRUCache<import("./websearch.js").SearchResult[]>;
export declare const pageCache: LRUCache<string>;
/**
 * Generate a cache key for search queries.
 * Normalizes the query for better cache hit rates.
 */
export declare function searchCacheKey(query: string): string;
/**
 * Generate a cache key for page fetches.
 */
export declare function pageCacheKey(url: string): string;
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