package node;

/**
	This module provides an implementation of a subset of the W3C [Web Performance APIs](https://w3c.github.io/perf-timing-primer/) as well as additional APIs for
	Node.js-specific performance measurements.
	
	Node.js supports the following [Web Performance APIs](https://w3c.github.io/perf-timing-primer/):
	
	* [High Resolution Time](https://www.w3.org/TR/hr-time-2)
	* [Performance Timeline](https://w3c.github.io/performance-timeline/)
	* [User Timing](https://www.w3.org/TR/user-timing/)
	* [Resource Timing](https://www.w3.org/TR/resource-timing-2/)
	
	```js
	const { PerformanceObserver, performance } = require('node:perf_hooks');
	
	const obs = new PerformanceObserver((items) => {
	   console.log(items.getEntries()[0].duration);
	   performance.clearMarks();
	});
	obs.observe({ type: 'measure' });
	performance.measure('Start to Now');
	
	performance.mark('A');
	doSomeLongRunningProcess(() => {
	   performance.measure('A to Now', 'A');
	
	   performance.mark('B');
	   performance.measure('A to B', 'A', 'B');
	});
	```
**/
@:jsRequire("perf_hooks") @valueModuleOnly extern class Perf_hooks {
	/**
		_This property is an extension by Node.js. It is not available in Web browsers._
		
		Creates an `IntervalHistogram` object that samples and reports the event loop
		delay over time. The delays will be reported in nanoseconds.
		
		Using a timer to detect approximate event loop delay works because the
		execution of timers is tied specifically to the lifecycle of the libuv
		event loop. That is, a delay in the loop will cause a delay in the execution
		of the timer, and those delays are specifically what this API is intended to
		detect.
		
		```js
		const { monitorEventLoopDelay } = require('node:perf_hooks');
		const h = monitorEventLoopDelay({ resolution: 20 });
		h.enable();
		// Do something.
		h.disable();
		console.log(h.min);
		console.log(h.max);
		console.log(h.mean);
		console.log(h.stddev);
		console.log(h.percentiles);
		console.log(h.percentile(50));
		console.log(h.percentile(99));
		```
	**/
	static function monitorEventLoopDelay(?options:node.perf_hooks.EventLoopMonitorOptions):node.perf_hooks.IntervalHistogram;
	/**
		Returns a `RecordableHistogram`.
	**/
	static function createHistogram(?options:node.perf_hooks.CreateHistogramOptions):node.perf_hooks.RecordableHistogram;
	static final performance : node.perf_hooks.Performance;
}