/**
 * LRU cache with max entries and max bytes limits.
 * Entry: { kind, version, expiresAt, value } per SPEC 12.3.
 *
 * Recency is a doubly linked list (head = most recent) indexed by a Map, so
 * hits and evictions are O(1) and never churn the Map's insertion order.
 * Cached values are replaced, never mutated, so each node stores its size.
 */
export interface LRUOptions {
    maxEntries?: number;
    maxBytes?: number;
}
export declare function createLRU<E extends {
    value: unknown;
}>(opts?: LRUOptions): {
    get: (key: string) => E | null;
    set: (key: string, entry: E) => void;
    del: (key: string) => void;
    clear: () => void;
    readonly stats: {
        entries: number;
        bytes: number;
        hits: number;
        misses: number;
        hitRatio: number;
    };
};