import type IIdempotencyStore from "./IIdempotencyStore";
/**
 * In-memory implementation of IIdempotencyStore.
 * Supports TTL-based expiration with automatic cleanup.
 *
 * Note: This implementation is suitable for single-process applications.
 * For distributed systems, use a Redis or database-backed implementation.
 */
export default class InMemoryIdempotencyStore implements IIdempotencyStore {
    private readonly keys;
    private cleanupInterval;
    private readonly cleanupIntervalMs;
    /**
     * Creates a new InMemoryIdempotencyStore.
     * @param cleanupIntervalMs Interval for automatic cleanup of expired keys (default: 60000ms = 1 minute)
     */
    constructor(cleanupIntervalMs?: number);
    exists(key: string): Promise<boolean>;
    mark(key: string, ttl?: number): Promise<void>;
    remove(key: string): Promise<void>;
    /**
     * Manually trigger cleanup of expired keys.
     * @returns The number of keys removed
     */
    cleanup(): number;
    /**
     * Get the current number of stored keys.
     */
    size(): number;
    /**
     * Clear all stored keys.
     */
    clear(): void;
    /**
     * Stop the automatic cleanup interval.
     * Should be called when the store is no longer needed to prevent memory leaks.
     */
    stopCleanup(): void;
    private startCleanup;
}