v8-profiler-next

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Description

v8-profiler-next provides node bindings for the v8 profiler.

I. Quick Start

  • Compatibility
    • node version: v4.x ~ v17.x
    • platform: mac, linux, windows

take cpu profile

'use strict';
const fs = require('fs');
const v8Profiler = require('v8-profiler-next');
const title = 'good-name';

// set generateType 1 to generate new format for cpuprofile
// to be compatible with cpuprofile parsing in vscode.
v8Profiler.setGenerateType(1);

// ex. 5 mins cpu profile
v8Profiler.startProfiling(title, true);
setTimeout(() => {
  const profile = v8Profiler.stopProfiling(title);
  profile.export(function (error, result) {
    // if it doesn't have the extension .cpuprofile then
    // chrome's profiler tool won't like it.
    // examine the profile:
    //   Navigate to chrome://inspect
    //   Click Open dedicated DevTools for Node
    //   Select the profiler tab
    //   Load your file
    fs.writeFileSync(`${title}.cpuprofile`, result);
    profile.delete();
  });
}, 5 * 60 * 1000);

take heapsnapshot

'use strict';
const v8Profiler = require('v8-profiler-next');
const snapshot = v8Profiler.takeSnapshot();
// 1. not as stream
snapshot.export(function (error, result) {
    if (error){
        console.error(error);
        return;
    }
    console.log(result);
    snapshot.delete();
});
// 2. as stream
const transform = snapshot.export();
transform.pipe(process.stdout);
transform.on('finish', snapshot.delete.bind(snapshot));

take allocation profile

Attention: If node version < v12.x, please use sampling heap profiling alone without cpu profiling or taking snapshot.

'use strict';
const v8Profiler = require('v8-profiler-next');
// set a leak array
const arraytest = [];
setInterval(() => {
  arraytest.push(new Array(1e2).fill('*').join());
}, 20);
// start 1min sampling profile
v8Profiler.startSamplingHeapProfiling();
setTimeout(() => {
    // stop and get allocation profile
    const profile = v8Profiler.stopSamplingHeapProfiling();
    // upload shf.heapprofile into chrome dev tools -> Memory -> ALLOCATION PRODILES
  require('fs').writeFileSync('./shf.heapprofile', JSON.stringify(profile));
    console.log(profile);
}, 60 * 1000);

II. License

MIT License

Copyright (c) 2018 team of v8-profiler, hyj1991

V8 Profiler Next

node bindings for the v8 profiler

V8 Profiler Next Info

⭐ Stars 113
🔗 Source Code github.com
🕒 Last Update 8 months ago
🕒 Created 5 years ago
🐞 Open Issues 2
➗ Star-Issue Ratio 57
😎 Author hyj1991