export interface CacheEntryOptions {
    /**
     * Importance level. Higher value means less likely to be evicted by GC.
     * Default: 1
     */
    importance?: number;
    /**
     * Time to live in milliseconds.
     */
    ttl?: number;
    /**
     * Absolute expiration date.
     */
    expiresAt?: number;
    /**
     * Arbitrary metadata (optional).
     */
    meta?: any;
}
export interface JkMemCacheOptions {
    /**
     * Name of the cache instance (used for logs).
     */
    name: string;
    /**
     * Maximum number of items in cache.
     * Default: Infinity
     */
    maxCount?: number;
    /**
     * Maximum size in bytes.
     * Default: 50MB (50 * 1024 * 1024)
     */
    maxSize?: number;
    /**
     * Interval in milliseconds for the recurrent GC.
     * Default: 60000 (1 minute)
     */
    cleanupInterval?: number;
}
export declare class JkMemCache {
    private _storage;
    private _currentSize;
    private _options;
    private _intervalId;
    private _name;
    constructor(options: JkMemCacheOptions);
    /**
     * Start the automatic cleanup interval.
     */
    startAutoCleanup(): void;
    /**
     * Stop the automatic cleanup interval.
     */
    stopAutoCleanup(): void;
    /**
     * Add or update an item in the cache.
     */
    set(key: string, value: string | ArrayBuffer | Uint8Array | object, options?: CacheEntryOptions): void;
    /**
     * Retrieve an item from the cache.
     */
    get<T = any>(key: string, peek?: boolean): T | null;
    /**
     * Retrieve an item from the cache with its metadata.
     */
    getWithMeta<T = any>(key: string, peek?: boolean): {
        value: T;
        meta: any;
        size: number;
    } | null;
    /**
     * Check if an item exists in the cache and is not expired.
     * Does not increment accessCount.
     */
    has(key: string): boolean;
    /**
     * Manually delete an item.
     */
    delete(key: string): void;
    /**
     * Clear all items.
     */
    clear(): void;
    /**
     * Get current cache stats.
     */
    getStats(): {
        count: number;
        size: number;
    };
    /**
     * Iterate over all valid keys.
     */
    keys(): Generator<string>;
    /**
     * Iterate over keys starting with a prefix.
     */
    keysStartingWith(prefix: string): Generator<string>;
    /**
     * Iterate over keys ending with a suffix.
     */
    keysEndingWith(suffix: string): Generator<string>;
    /**
     * Iterate over keys containing a specific text.
     */
    keysContaining(text: string): Generator<string>;
    /**
     * Check if we need to evict entries to fit a new one (or if limits are exceeded).
     */
    private needsEviction;
    /**
     * Perform recurrent cleanup (expiration only).
     */
    private performCleanup;
    /**
     * Evict items to make space/reduce count.
     * Strategy: Calculate a score. Lower score = evicted first.
     * Factors:
     * - expired (immediate kill)
     * - importance (higher = keep)
     * - accessCount (higher = keep)
     *
     * Score = (importance * 1000) + (accessCount)
     * (Simplified logic)
     */
    private evictFor;
}