import * as plugins from '../plugins.js';
import { type INetworkProxyOptions } from './classes.np.types.js';
/**
 * Manages a pool of backend connections for efficient reuse
 */
export declare class ConnectionPool {
    private options;
    private connectionPool;
    private roundRobinPositions;
    private logger;
    constructor(options: INetworkProxyOptions);
    /**
     * Get a connection from the pool or create a new one
     */
    getConnection(host: string, port: number): Promise<plugins.net.Socket>;
    /**
     * Return a connection to the pool for reuse
     */
    returnConnection(socket: plugins.net.Socket, host: string, port: number): void;
    /**
     * Cleanup the connection pool by removing idle connections
     * or reducing pool size if it exceeds the configured maximum
     */
    cleanupConnectionPool(): void;
    /**
     * Close all connections in the pool
     */
    closeAllConnections(): void;
    /**
     * Get load balancing target using round-robin
     */
    getNextTarget(targets: string[], port: number): {
        host: string;
        port: number;
    };
    /**
     * Gets the connection pool status
     */
    getPoolStatus(): Record<string, {
        total: number;
        idle: number;
    }>;
    /**
     * Setup a periodic cleanup task
     */
    setupPeriodicCleanup(interval?: number): NodeJS.Timeout;
}