import { Middleware, MiddlewareRequestHandler } from './middleware';
import { MomentoLoggerFactory } from '@gomomento/sdk-core';
/**
 * This middleware enables event-loop performance metrics.It runs a periodic task specified by metricsLogInterval
 * to gather various event-loop metrics that can be correlated with the overall application's performance. This is
 * particularly helpful to analyze and correlate resource contention with higher network latencies.
 *
 * See {@link StateMetrics} for each heuristic/metric and their description.
 */
export declare class ExperimentalEventLoopPerformanceMetricsMiddleware implements Middleware {
    private readonly metricsLogInterval;
    private readonly eventLoopDelayInterval;
    private eldMonitor;
    private elu;
    private isLoggingStarted;
    private intervalId;
    private readonly logger;
    constructor(loggerFactory: MomentoLoggerFactory);
    init(): void;
    private startLogging;
    onNewRequest(): MiddlewareRequestHandler;
    close(): void;
}