node-perf-timer

Measuring elapsed time in Node, made simple.

Motivation

Node's native timing function – process.hrtime() – is extremely precise, but low-level and messy to use for profiling without any abstraction on top of it.

node-perf-timer aims to provide a simple API to provide a more intuitive developer experience when measuring elapsed time in Node applications.

Requirements

• Node v4.x or higher

Installation

npm i --save-dev node-perf-timer

or

yarn add node-perf-timer --dev

Usage

const perfTimer = require('node-perf-timer')

// start a timer
perfTimer.start();

functionToBeMeasured();

// returns diff in nanoseconds & logs (by default):
// Message: functionToBeMeasured()
// Duration: 0 s, 3.589862 ms
const nsDiff = perfTimer.stopAndDiff('functionToBeMeasured()');

Configuration

By default, the configuration object takes the following shape:

const opts = {
  shouldPrint: true, // should diffs be logged to the console?
  precision: undefined, // e.g. `4`; how many decimal places to use for millisecond formatting
  defaultMessage: undefined, // e.g. `"hello bottleneck!"`; default message for each diff being logged
};

API

• config(configObj) - Adjust default opts for all future perfTimer calls.
• start() - Starts a new timer and returns the absolute start time in nanoseconds.
• stop() - Stops the current timer and returns the absolute end time in nanoseconds.
• diff(nsStartTime, nsEndTime) - Accepts a start & end time in nanoseconds and returns the difference.
• stopAndDiff(message?) - Combines stop() & diff(). If opts.shouldPrint is set, the diff is logged to the console with message, opts.defaultMessage or simply the duration.
• stopAndRestart() - Stops timer, starts a new one and returns the nanosecond diff of the stopped timer.

Full API Documentation

Examples

Examples for a number of common use cases can be found here (WIP).

License

MIT