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