Measure process time with Node Js?
Since you are targeting nodejs, you can use process.hrtime
as stated in the docs
The process.hrtime() method returns the current high-resolution real time in a [seconds, nanoseconds] tuple Array, where nanoseconds is the remaining part of the real time that can't be represented in second precision.
So you can measure timings up to nanosecond, something that console.time
can't, as you can see in your example console.time
or Date
difference measures 0s.
For example:
const NS_PER_SEC = 1e9;
const MS_PER_NS = 1e-6
const time = process.hrtime();
for (let i; i < 10000; i++) {
// Just to simulate the process
}
const diff = process.hrtime(time);
console.log(`Benchmark took ${diff[0] * NS_PER_SEC + diff[1]} nanoseconds`);
console.log(`Benchmark took ${ (diff[0] * NS_PER_SEC + diff[1]) * MS_PER_NS } milliseconds`);
Since I'm using timers in multiple places, I wrote a simple class based on Alex's answer:
const t = new Timer('For Loop')
// your code
t.runtimeMs() // => 1212.34
t.runtimeMsStr() // => 'For Loop took 1232.34 milliseconds'
Here's the code:
class Timer {
// Automatically starts the timer
constructor(name = 'Benchmark') {
this.NS_PER_SEC = 1e9;
this.MS_PER_NS = 1e-6
this.name = name;
this.startTime = process.hrtime();
}
// returns the time in ms since instantiation
// can be called multiple times
runtimeMs() {
const diff = process.hrtime(this.startTime);
return (diff[0] * this.NS_PER_SEC + diff[1]) * this.MS_PER_NS;
}
// retuns a string: the time in ms since instantiation
runtimeMsStr() {
return `${this.name} took ${this.runtimeMs()} milliseconds`;
}
}