teeny-perf

Performance and benchmarking utilities for Node

Table of Content

• Installation
• API
  • Benchmark
  • HighResTimer
  • Performance
• License

Installation

> cd your-project
> npm install teeny-perf

API

Benchmark

Benchmark is a class that provides a simple benchmarking tool for node, relying on the original benchmark module that use to power the now-defunct jsPerf website, and heavily inspired by the great benny.

Constructor

The constructor requires a string: the name for the benchmark suite. It also takes an optional second argument: an object defining if the test should be verbose (default) or not.

To make a test silent, instantiate a benchmark suite as follows:

const { Benchmark } = require("teeny-js-utilities");
const bench = new Benchmark("My test suite", { verbose: false });

Methods

add(name, function)

Adds a test to the suite.

Argument	Type	Default	Description
name	string		the name of the test
function	Function		The function to run

async run() => {results}

Runs the Benchmark suite.

Examples

const { Benchmark } = require("teeny-js-utilities");
const bench = new Benchmark("My test suite");

bench.add("Regex", () => {
  /o/.test("Hello World!");
});
bench.add("IndexOf", () => {
  "Hello World!".indexOf("o") > -1;
});
// if setup is required, the test should be wrapped
bench.add("Cached Regex", () => {
  // Some setup:
  const re = /o/;
  // Benchmarked code wrapped in a function:
  return () => re.test("Hello World!");
});

const results = bench.run();

/**
 * Because the test suite is verbose by default, it would
 * print something like:
 *
 * ┌──────────────┬─────────────┬────────────────┬─────────────────┬─────────┐
 * │ Name         │     Ops/sec │ Percent slower │ Margin of error │    Rank │
 * ├──────────────┼─────────────┼────────────────┼─────────────────┼─────────┤
 * │ Regex        │  49,106,105 │         94.65% │          ±1.16% │ Slowest │
 * ├──────────────┼─────────────┼────────────────┼─────────────────┼─────────┤
 * │ IndexOf      │ 917,842,104 │             0% │          ±1.26% │ Fastest │
 * ├──────────────┼─────────────┼────────────────┼─────────────────┼─────────┤
 * │ Cached Regex │  56,337,056 │         93.86% │          ±1.16% │         │
 * └──────────────┴─────────────┴────────────────┴─────────────────┴─────────┘
 *
 */

HighResTimer

HighResTimer is a class that provides a high-resolution timer based on process.hrtime.bigint() and a nodejs polyfill for window.requestAnimationFrame().

Constructor

The constructor requires a number: the time in milliseconds for the timer to run.

Methods

Method	Description
start	Start the timer
cancel	Cancel the timer before its time is due

Events

Name	Description
EVENT_CANCEL	Event sent when the timer is cancelled
EVENT_COMPLETE	Event sent when the timer has terminated
EVENT_START	Event sent when the timer starts
EVENT_TICK	Event sent at each process.tick

Examples

const {
  HighResTimer,
  EVENT_START,
  EVENT_TICK,
  EVENT_COMPLETE,
} = require("teeny-perf");

const timer = new HighResTimer(250);
timer
  .on(EVENT_START, () => {
    console.log("-> Timer has started");
  })
  .on(EVENT_TICK, () => {
    console.log("-> tick...");
  })
  .on(EVENT_COMPLETE, () => {
    console.log("-> Timer is done!");
  })
  .start();

Performance

Performance is a wrapper around nodejs Performance measurement APIs.

It provides a highly simplified class for an extremely simple case:

• start performance monitoring
• do something that takes a while
• stop performance monitoring
• read how much time passed between start and stop (in milliseconds)
• rinse and repeat

Methods

Method	Description
start	Starts measuring performance
stop	Stops measuring performance and store the result

Getter	Type	Description
results	Object
results.duration	Number	Time in milliseconds

Examples

Basic performance gathering

const { Performance } = require("teeny-js-utilities");
const perf = new Performance();

// somewhere in your code, you want to start measuring performance:
perf.start();
// do long lasting actions
(...)
// when done, tell performance to stop:
perf.stop();
// the duration can now be found in the Performance class getter `results`:
console.log(`It took ${perf.results.duration} milliseconds to run...`);

Multiple performance gatherings

const { Performance } = require("teeny-js-utilities");
const perf = new Performance();

// somewhere in your code, you want to start measuring performance:
perf.start();
// do long lasting actions
(...)
// when done, tell performance to stop:
perf.stop();
// Save the results
const res1 = perf.results.duration;

// further down in your code, start measuring another performance:
perf.start();
// do other long lasting actions
(...)
// when done, tell performance to stop:
perf.stop();
// Save the results
const res2 = perf.results.duration;

// -> res1 and res2 will have 2 different duration results.

License

MIT © Arno Versini