How can measure response time for event-based NodeJs a-CodePudding

I have a scenario like this:

There is a NodeJS client application that calls an API service. Then the client then rises a listener to get a response.

Now I need to measure the response time from the API is called until the client receives the event.

Finally, I want to do performance testing for it.

//1) call API

//2) rise listener
context.events.myEvent().on('data', async event => {
      
      console.log("result"); 

 //3) here needs to measure Response time

});

Please help me to solve it.

CodePudding user response：

You can use console.time() and console.timeEnd()

Call console.time() when you want to start the timer and console.timeEnd() to stop and print the elapsed time.

//1) call API
console.time("response time")

//2) rise listener
context.events.myEvent().on('data', async event => {
  //3) here needs to measure Response time
  console.timeEnd("response time")
});

documentation: console.time, console.timeEnd

If you need it in the form of a variable you have to manually get the timestamps and calculate it

//1) call API
let start = new Date().getTime()

//2) rise listener
context.events.myEvent().on('data', async event => {
  let end = new Date().getTime()

  //3) here needs to measure Response time
  let elapsedTime = end - start;
});

CodePudding user response：

For anyone want to get time elapsed value instead of console output :

use process.hrtime(), below is my simpler approach :


context.events.myEvent().on('data', async event => {
    var startTime = process.hrtime();
    var elapsedSeconds = parseHrtimeToSeconds(process.hrtime(startTime));
    console.log('It takes '   elapsedSeconds   'seconds');
});

function parseHrtimeToSeconds(hrtime) {
    var seconds = (hrtime[0]   (hrtime[1] / 1e9)).toFixed(3);
    return seconds;
}