Book Image

Node Cookbook - Third Edition

By : Matteo Collina, David Mark Clements, Elger, Mathias Buus Madsen
Book Image

Node Cookbook - Third Edition

By: Matteo Collina, David Mark Clements, Elger, Mathias Buus Madsen

Overview of this book

Today's web demands efficient real-time applications and scalability. Asynchronous event-driven programming is ideal for this, and this is where Node.js comes in. Server-side JavaScript has been here since the 90s, but Node got it right. With Node for tooling and server-side logic, and a browser-based client-side UI, everything is JavaScript. This leads to rapid, fluid development cycles. The full-stack, single language experience means less context-switching between languages for developers, architects and whole teams. This book shows you how to build fast, efficient, and scalable client-server solutions using the latest versions of Node. The book begins with debugging tips and tricks of the trade, and how to write your own modules. Then you'll learn the fundamentals of streams in Node.js, discover I/O control, and how to implement the different web protocols. You'll find recipes for integrating databases such as MongoDB, MySQL/MariaDB, Postgres, Redis, and LevelDB. We also cover the options for building web application with Express, Hapi and Koa. You will then learn about security essentials in Node.js and advanced optimization tools and techniques. By the end of the book you will have acquired the level of expertise to build production-ready and scalable Node.js systems. The techniques and skills you will learn in this book are based on the best practices developed by nearForm, one of the leaders in Node implementations, who supported the work of the authors on this book.
Table of Contents (12 chapters)

Piping streams in production

The pipe method is one of the most well-known features of streams. It allows us to compose advanced streaming pipelines as a single line of code.

As a part of Node core it can be useful for cases where process uptime isn't important (such as CLI tools).

Unfortunately, however, it lacks a very important feature: error handling.

If one of the streams in a pipeline composed with pipe fails, the pipeline is simply unpiped. It is up to us to detect the error and then afterwards destroy the remaining streams so they do not leak any resources. This can easily lead to memory leaks.

Let's consider the following example:

const http = require('http') 
const fs = require('fs')

const server = http.createServer((req, res) => {
fs.createReadStream('big.file').pipe(res)
})

server.listen(8080)

A simple, straightforward...