import type { MiddlewareHandler } from "./types.js";
/**
 * Connection tracking for throttling
 */
interface ConnectionInfo {
    clientIp: string;
    connectedAt: number;
}
/**
 * Configuration for connection throttling
 */
export interface ConnectionThrottleConfig {
    /** Enable connection throttling */
    enabled: boolean;
    /** Maximum concurrent connections globally */
    maxGlobal: number;
    /** Maximum concurrent connections per IP */
    maxPerIp: number;
}
/**
 * Connection throttling middleware
 * Limits concurrent connections globally and per-IP to prevent resource exhaustion
 */
export declare function connectionThrottle(config?: Partial<ConnectionThrottleConfig>): MiddlewareHandler;
/**
 * Get connection stats for monitoring
 */
export declare function getConnectionStats(activeConnections: Map<string, ConnectionInfo>, connectionsPerIp: Map<string, Set<string>>): {
    totalConnections: number;
    uniqueIps: number;
    topIps: Array<{
        ip: string;
        count: number;
    }>;
};
export {};