/**
 * Keyed in-memory store with periodic stale-entry sweep. Internal helper for
 * the rate-limit primitives — keep it package-private (re-export only via
 * `infra/rate-limit/index.ts` if a real consumer appears).
 *
 * Lifecycle: `new` → use → `destroy()`. Buckets created from this store are
 * registered in the gateway's bucket registry, which calls `destroy()` on
 * graceful shutdown so the cleanup timer doesn't leak.
 */
export type Clock = () => number;
export type KeyedStoreOptions = {
    /** Drop entries whose `lastTouchedMs` is older than this. */
    staleAfterMs: number;
    /** How often the sweep runs. Defaults to `staleAfterMs / 4` (capped at 10min). */
    cleanupIntervalMs?: number;
    /** Injected clock for deterministic tests. */
    clock?: Clock;
};
export declare class KeyedStore<V extends {
    lastTouchedMs: number;
}> {
    private readonly map;
    private readonly clock;
    private readonly staleAfterMs;
    private cleanupTimer?;
    constructor(opts: KeyedStoreOptions);
    get(key: string): V | undefined;
    set(key: string, value: V): void;
    delete(key: string): void;
    size(): number;
    clear(): void;
    destroy(): void;
    private sweep;
}