CODEWITHSUNDEEP
javascriptnode.jsprofiling
Stormshadow
Stormshadow

Reputation: 7159

How do I measure the execution time of JavaScript code with callbacks?

I have a piece of JavaScript code that I am executing using the node.js interpreter.

for(var i = 1; i < LIMIT; i++) {
  var user = {
    id: i,
    name: "MongoUser [" + i + "]"
  };
  db.users.save(user, function(err, saved) {
    if(err || !saved) {
      console.log("Error");
    } else {
      console.log("Saved");
    }
  });
}

How can I measure the time taken by these database insert operations? I could compute the difference of date values after and before this piece of code but that would be incorrect because of the asynchronous nature of the code.

Upvotes: 482

Views: 405621

Answers (14)

satk0
satk0

Reputation: 514

Big Brain Method using performance.now():

let stime = performance.now();     // started time
executeSomething()                      
let ftime = performance.now();     // finished time

let elapsed_time = ftime - stime;  
console.log(`Execution time: ${elapsed_time} ms`);

performance.now method returns timestamp from the time origin (in miliseconds).

By substracting the started time from the finished time you can easily get the elapsed time and, most importantly, have it stored in a variable.

Upvotes: 9

Vitor Barbosa
Vitor Barbosa

Reputation: 31

Here's how I'm doing it in 2024, using ES6+ syntax.

To return the total time in seconds:

const time = process.hrtime()
/* add the function to be timed here, between time and endTime */
const endTime = process.hrtime(time)
const seconds = endTime[0]
const nanosecondsConvertedToSeconds = endTime[1] / 1e9
const totalSeconds = seconds + nanosecondsConvertedToSeconds

Upvotes: 1

user2362662
user2362662

Reputation: 10202

Use the Node.js console.time() and console.timeEnd():

var i;
console.time("dbsave");

for(i = 1; i < LIMIT; i++){
    db.users.save({id : i, name : "MongoUser [" + i + "]"}, end);
}

end = function(err, saved) {
    console.log(( err || !saved )?"Error":"Saved");
    if(--i === 1){
      console.timeEnd("dbsave");
    }
};

Upvotes: 1003

shpiglify
shpiglify

Reputation: 19

I designed a simple method for this, using console.time() & console.timeEnd():

measure function definition
function measureRunningTime(func,...args){
    const varToString = varObj => Object.keys(varObj)[0]
    const displayName = func.name || varToString({ func })
    console.time(displayName)
    func(...args)
    console.timeEnd(displayName)
}

To use it, pass a function without arguments, with arguments binded, or with arguments as the following parameters.

Examples:

let's say I want to check the running time of the simplest searching algorithm - SimpleSearch:
measured function definition (your code here)
const simpleSearch = (array = [1,2,3] ,item = 3) => {
    for(let i = 0; i< array.length; i++){
        if (array[i] === item) return i;
    }
    return -1
}
implementation without arguments
measureRunningTime(simpleSearch) 
//Prints something like that-> simpleSearch: 0.04ms
implementation with arguments using .bind()
const array = [1,2,3]
const item = 3
measureRunningTime(simpleSearch.bind(null, array, item))
//Prints something like that-> bound simpleSearch: 0.04ms
implementation with arguments without using .bind()
const array = [1,2,3]
const item = 3
measureRunningTime(simpleSearch, array, item)
//Prints something like that-> simpleSearch: 0.04ms

-> Take notice!! this implementation is far from perfect - for example there is no error handling - but it can be used to check the running times of simple algorithms, Moreover , I'm not an experienced programmer so take everything with a grain of salt 🧂 👌

Upvotes: 1

Ulad Kasach
Ulad Kasach

Reputation: 12818

You can use a wrapper function to easily report the execution time of any existing function.

A wrapper is a used to extend an existing function to do something before and after the existing function's execution - and is a convenient way to compose logic.

Here is an example of using the withDurationReporting wrapper:

// without duration reporting
const doSomethingThatMayTakeAWhile = async (someArg: string, anotherArg: number) => { 
  /** your logic goes here */
}

// with duration reporting
const doSomethingThatMayTakeAWhileWithReporting = withDurationReporting(
  'doSomethingThatMayTakeAWhile', 
  doSomethingThatMayTakeAWhile
);

// note: you can define the function with duration reporting directly, too
const doSomethingThatMayTakeAWhile = withDurationReporting(
  'doSomethingThatMayTakeAWhile', 
  async (someArg: string, anotherArg: number) => { 
    /** your logic goes here */
  }
)

And here is the wrapper itself:

import { hrtime } from 'process';

const roundToHundredths = (num: number) => Math.round(num * 100) / 100; // https://stackoverflow.com/a/14968691/3068233

/**
 * a wrapper which reports how long it took to execute a function, after the function completes
 */
export const withDurationReporting = <R extends any, T extends (...args: any[]) => Promise<R>>(
  title: string,
  logic: T,
  options: {
    reportingThresholdSeconds: number;
    logMethod: (message: string, metadata?: Record<string, any>) => void;
  } = {
    reportingThresholdSeconds: 1, // report on anything that takes more than 1 second, by default
    logMethod: console.log, // log with `console.log` by default
  }, 
) => {
  return (async (...args: Parameters<T>): Promise<R> => {
    const startTimeInNanoseconds = hrtime.bigint();
    const result = await logic(...args);
    const endTimeInNanoseconds = hrtime.bigint();
    const durationInNanoseconds = endTimeInNanoseconds - startTimeInNanoseconds;
    const durationInSeconds = roundToHundredths(Number(durationInNanoseconds) / 1e9); // https://stackoverflow.com/a/53970656/3068233
    if (durationInSeconds >= options.reportingThresholdSeconds)
      options.logMethod(`${title} took ${durationInSeconds} seconds to execute`, { title, durationInSeconds });
    return result;
  }) as T;
};

Upvotes: 2

Ighor Martins
Ighor Martins

Reputation: 11

I need this to be cumulative, and to measure different stuff.
Built these functions:

function startMeasuring(key) {
  measureTimers[key] = process.hrtime();
}

function stopMeasuring(key) {
  if (!measures[key]) {
    measures[key] = 0;
  }

  let hrtime = process.hrtime(measureTimers[key]);
  measures[key] += hrtime[0] + hrtime[1] / 1e9;
  measureTimers[key] = null;
}

Usage:

startMeasuring("first Promise");
startMeasuring("first and second Promises");
await new Promise((resolve) => {
  setTimeout(resolve, 1400);
});
stopMeasuring("first Promise");
stopMeasuring("first and second Promises");

startMeasuring("first and second Promises");
await new Promise((resolve) => {
  setTimeout(resolve, 600);
});
stopMeasuring("first and second Promises");

console.log("Measure Results", measures); 
/*
Measusre Results {
  setting: 0.00002375,
  'first Promise': 1.409392916,
  'first and second Promise': 2.015160376
}
*/

Upvotes: 0

Alexandru Savin
Alexandru Savin

Reputation: 636

You could also try exectimer. It gives you feedback like:

var t = require("exectimer");

var myFunction() {
   var tick = new t.tick("myFunction");
   tick.start();
   // do some processing and end this tick
   tick.stop();
}

// Display the results
console.log(t.timers.myFunction.duration()); // total duration of all ticks
console.log(t.timers.myFunction.min()); // minimal tick duration
console.log(t.timers.myFunction.max()); // maximal tick duration
console.log(t.timers.myFunction.mean()); // mean tick duration
console.log(t.timers.myFunction.median()); // median tick duration

[edit] There is an even simpler way now to use exectime. Your code could be wrapped like this:

var t = require('exectimer'),
Tick = t.Tick;

for(var i = 1; i < LIMIT; i++){
    Tick.wrap(function saveUsers(done) {
        db.users.save({id : i, name : "MongoUser [" + i + "]"}, function(err, saved) {
            if( err || !saved ) console.log("Error");
            else console.log("Saved");
            done();
        });
    });
}

// Display the results
console.log(t.timers.myFunction.duration()); // total duration of all ticks
console.log(t.timers.saveUsers.min()); // minimal tick duration
console.log(t.timers.saveUsers.max()); // maximal tick duration
console.log(t.timers.saveUsers.mean()); // mean tick duration
console.log(t.timers.saveUsers.median()); // median tick duration

Upvotes: 3

Cody Geisler
Cody Geisler

Reputation: 8617

Surprised no one had mentioned yet the new built in libraries:

Available in Node >= 8.5, and should be in Modern Browers

https://developer.mozilla.org/en-US/docs/Web/API/Performance

https://nodejs.org/docs/latest-v8.x/api/perf_hooks.html#

Node 8.5 ~ 9.x (Firefox, Chrome)

// const { performance } = require('perf_hooks'); // enable for node
const delay = time => new Promise(res=>setTimeout(res,time))
async function doSomeLongRunningProcess(){
  await delay(1000);
}
performance.mark('A');
(async ()=>{
  await doSomeLongRunningProcess();
  performance.mark('B');
  performance.measure('A to B', 'A', 'B');
  const measure = performance.getEntriesByName('A to B')[0];
  // firefox appears to only show second precision.
  console.log(measure.duration);
  // apparently you should clean up...
  performance.clearMarks();
  performance.clearMeasures();         
  // Prints the number of milliseconds between Mark 'A' and Mark 'B'
})();

https://repl.it/@CodyGeisler/NodeJsPerformanceHooks

Node 12.x

https://nodejs.org/docs/latest-v12.x/api/perf_hooks.html

const { PerformanceObserver, performance } = require('perf_hooks');
const delay = time => new Promise(res => setTimeout(res, time))
async function doSomeLongRunningProcess() {
    await delay(1000);
}
const obs = new PerformanceObserver((items) => {
    console.log('PerformanceObserver A to B',items.getEntries()[0].duration);
      // apparently you should clean up...
      performance.clearMarks();
      // performance.clearMeasures(); // Not a function in Node.js 12
});
obs.observe({ entryTypes: ['measure'] });

performance.mark('A');

(async function main(){
    try{
        await performance.timerify(doSomeLongRunningProcess)();
        performance.mark('B');
        performance.measure('A to B', 'A', 'B');
    }catch(e){
        console.log('main() error',e);
    }
})();

Upvotes: 51

Sing
Sing

Reputation: 4052

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

use process.hrtime() as @D.Deriso suggestion, below is my simpler approach : 

function functionToBeMeasured() {
    var startTime = process.hrtime();
    // do some task...
    // ......
    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;
}

Upvotes: 41

jfcorugedo
jfcorugedo

Reputation: 10051

Invoking console.time('label') will record the current time in milliseconds, then later calling console.timeEnd('label') will display the duration from that point.

The time in milliseconds will be automatically printed alongside the label, so you don't have to make a separate call to console.log to print a label:

console.time('test');
//some code
console.timeEnd('test'); //Prints something like that-> test: 11374.004ms

For more information, see Mozilla's developer docs on console.time.

Upvotes: 184

Manohar Reddy Poreddy
Manohar Reddy Poreddy

Reputation: 27395

I had same issue while moving from AWS to Azure

For express & aws, you can already use, existing time() and timeEnd()

For Azure, use this: https://github.com/manoharreddyporeddy/my-nodejs-notes/blob/master/performance_timers_helper_nodejs_azure_aws.js

These time() and timeEnd() use the existing hrtime() function, which give high-resolution real time.

Hope this helps.

Upvotes: 2

Onur Yıldırım
Onur Yıldırım

Reputation: 33634

Old question but for a simple API and light-weight solution; you can use perfy which uses high-resolution real time (process.hrtime) internally.

var perfy = require('perfy');

function end(label) {
    return function (err, saved) {
        console.log(err ? 'Error' : 'Saved'); 
        console.log( perfy.end(label).time ); // <——— result: seconds.milliseconds
    };
}

for (var i = 1; i < LIMIT; i++) {
    var label = 'db-save-' + i;
    perfy.start(label); // <——— start and mark time
    db.users.save({ id: i, name: 'MongoUser [' + i + ']' }, end(label));
}

Note that each time perfy.end(label) is called, that instance is auto-destroyed.

Disclosure: Wrote this module, inspired by D.Deriso's answer. Docs here.

Upvotes: 10

D.Deriso
D.Deriso

Reputation: 4397

There is a method that is designed for this. Check out process.hrtime(); .

So, I basically put this at the top of my app.

var start = process.hrtime();

var elapsed_time = function(note){
    var precision = 3; // 3 decimal places
    var elapsed = process.hrtime(start)[1] / 1000000; // divide by a million to get nano to milli
    console.log(process.hrtime(start)[0] + " s, " + elapsed.toFixed(precision) + " ms - " + note); // print message + time
    start = process.hrtime(); // reset the timer
}

Then I use it to see how long functions take. Here's a basic example that prints the contents of a text file called "output.txt":

var debug = true;
http.createServer(function(request, response) {

    if(debug) console.log("----------------------------------");
    if(debug) elapsed_time("recieved request");

    var send_html = function(err, contents) {
        if(debug) elapsed_time("start send_html()");
        response.writeHead(200, {'Content-Type': 'text/html' } );
        response.end(contents);
        if(debug) elapsed_time("end send_html()");
    }

    if(debug) elapsed_time("start readFile()");
    fs.readFile('output.txt', send_html);
    if(debug) elapsed_time("end readFile()");

}).listen(8080);

Here's a quick test you can run in a terminal (BASH shell):

for i in {1..100}; do echo $i; curl http://localhost:8080/; done

Upvotes: 268

Andrey Sidorov
Andrey Sidorov

Reputation: 25456

var start = +new Date();
var counter = 0;
for(var i = 1; i < LIMIT; i++){
    ++counter;
    db.users.save({id : i, name : "MongoUser [" + i + "]"}, function(err, saved) {
          if( err || !saved ) console.log("Error");
          else console.log("Saved");
          if (--counter === 0) 
          {
              var end = +new Date();
              console.log("all users saved in " + (end-start) + " milliseconds");
          }
    });
}

Upvotes: 18

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