/**
 * Performance measurement utilities
 */
import type { InternalResourceMeasurement } from '../types/middleware.types';
/**
 * Get current resource usage measurement
 */
export declare function getCurrentResourceMeasurement(): InternalResourceMeasurement;
/**
 * Calculate memory delta between two measurements
 */
export declare function calculateMemoryDelta(start: InternalResourceMeasurement, end: InternalResourceMeasurement): number;
/**
 * Calculate CPU time delta between two measurements (in microseconds)
 */
export declare function calculateCpuTimeDelta(start: InternalResourceMeasurement, end: InternalResourceMeasurement): number;
/**
 * Convert microseconds to seconds for metrics
 */
export declare function microsecondsToSeconds(microseconds: number): number;
/**
 * Calculate duration in seconds from start time
 */
export declare function calculateDurationSeconds(startTime: number): number;
/**
 * Get system memory usage percentage
 */
export declare function getSystemMemoryUsagePercent(): number;
/**
 * Get system CPU usage percentage (approximation)
 */
export declare function getSystemCpuUsagePercent(): number;
/**
 * Generate high-resolution timestamp for precise measurements
 */
export declare function getHighResolutionTime(): number;
/**
 * Calculate high-resolution duration in milliseconds
 */
export declare function calculateHighResDuration(startTime: number): number;