/**
 * Token Bucket Rate Limiter for URL Downloads
 *
 * Implements a token bucket algorithm to limit concurrent URL downloads.
 * This prevents DoS attacks from rapid URL download requests.
 *
 * Default configuration: 10 downloads per second
 */
import type { RateLimiterConfig } from "../types/index.js";
/**
 * Token Bucket Rate Limiter
 *
 * Uses a token bucket algorithm where:
 * - Tokens are consumed when a download is requested
 * - Tokens are refilled at a fixed rate
 * - Requests that exceed the limit are queued
 */
export declare class TokenBucketRateLimiter {
    private tokens;
    private config;
    private queue;
    private refillTimer;
    private lastRefillTime;
    constructor(config?: Partial<RateLimiterConfig>);
    /**
     * Start the token refill timer
     */
    private startRefillTimer;
    /**
     * Refill tokens based on elapsed time
     */
    private refillTokens;
    /**
     * Process queued requests when tokens become available
     */
    private processQueue;
    /**
     * Acquire a token for a download
     * Returns immediately if token is available, otherwise queues the request
     *
     * @throws NeuroLinkError if queue is full or request times out
     */
    acquire(): Promise<void>;
    /**
     * Get current rate limiter statistics
     */
    getStats(): {
        availableTokens: number;
        queueLength: number;
        maxTokens: number;
        maxQueueSize: number;
    };
    /**
     * Reset the rate limiter to initial state
     */
    reset(): void;
    /**
     * Stop the rate limiter and clean up resources
     */
    stop(): void;
}
/**
 * Global rate limiter instance for URL downloads
 * Default: 10 downloads per second
 */
export declare const urlDownloadRateLimiter: TokenBucketRateLimiter;
/**
 * Rate-limited wrapper for async functions
 * Ensures the function is rate-limited using the provided rate limiter
 *
 * @param fn - The async function to wrap
 * @param rateLimiter - The rate limiter to use (defaults to urlDownloadRateLimiter)
 * @returns A rate-limited version of the function
 */
export declare function withRateLimit<T extends unknown[], R>(fn: (...args: T) => Promise<R>, rateLimiter?: TokenBucketRateLimiter): (...args: T) => Promise<R>;