window.performance.now() equivalent in nodejs?
Javascriptnode.jsNavigation Timing-ApiJavascript Problem Overview
I think the question is straight forward.
I'm looking for something that's similar to window.performance.now() in nodejs V8 engine.
Right now I'm just using:-
var now = Date.now();
//do some processing..
console.log("time elapsed:", Date.now() - now);
But, I read that window.performance.now() is lot more accurate than using the date because of the what's defined here.
Javascript Solutions
Solution 1 - Javascript
Node v8.5.0 has added Performance Timing API, which includes the performance#now()
, e.g.
const {
performance
} = require('perf_hooks');
console.log('performance', performance.now());
Solution 2 - Javascript
I would only mention that three of the reasons the author gives for the preference of the timing API in the browser wouldn't seem to apply directly to a node situation, and the fourth, the inaccuracy of Javscript time, cites an article from 2008, and I would strongly caution against relying on older material regarding Javascript performance specifics, particularly given the recent round of performance improvements all the engines have made to support "HTML5" apps.
However, in answer to your question, you should look at process.hrtime()
UPDATE: The present
package (available via npm install present
) provides some sugar around hrtime
if you'd like it.
Note: Since the version 8.5.0 of Node, you can use performance.now()
Solution 3 - Javascript
Here's a shortcut for process.hrtime()
that returns milliseconds instead of microseconds:
function clock(start) {
if ( !start ) return process.hrtime();
var end = process.hrtime(start);
return Math.round((end[0]*1000) + (end[1]/1000000));
}
Usage:
var start = clock();
// do some processing that takes time
var duration = clock(start);
console.log("Took "+duration+"ms");
Will output something like "Took 200ms"
Solution 4 - Javascript
What about?
console.time('FooTimer');
// do the work
console.timeEnd('FooTimer');
Solution 5 - Javascript
process.uptime()
> "The process.uptime()
method returns the number of seconds the
> current Node.js process has been running.
>
> The return value includes fractions of a second. Use Math.floor()
to
> get whole seconds."
Example: Measure For Loop Execution Time
const nemo = ['nemo'];
function findNemo(array) {
let start_time = process.uptime();
for (let iteration = 0; iteration < array.length; iteration++) {
if (array[iteration] === 'nemo') {
console.log("Found Nemo");
}
}
let end_time = process.uptime();
console.log("For loop took this much time: ", end_time - start_time);
}
findNemo(nemo);
Example Output
Solution 6 - Javascript
Here's a Typescript version with process.hrtime(), based on NextLocal's answer:
class Benchmark {
private start = process.hrtime();
public elapsed(): number {
const end = process.hrtime(this.start);
return Math.round((end[0] * 1000) + (end[1] / 1000000));
}
}
export = Benchmark;
Usage:
import Benchmark = require("./benchmark");
const benchmark = new Benchmark();
console.log(benchmark.elapsed());
Solution 7 - Javascript
To sum up and avoiding using perf_hooks
const performance = {
now: function(start) {
if ( !start ) return process.hrtime();
var end = process.hrtime(start);
return Math.round((end[0]*1000) + (end[1]/1000000));
}
}
console.log('performance', performance.now());
Solution 8 - Javascript
This method came into existence in version 8.5.0 of nodejs https://nodejs.org/api/perf_hooks.html#perf_hooks_performance_measurement_apis