You are previewing Smashing Node.js: JavaScript Everywhere, 2nd Edition.

Smashing Node.js: JavaScript Everywhere, 2nd Edition

Cover of Smashing Node.js: JavaScript Everywhere, 2nd Edition by Guillermo Rauch Published by John Wiley & Sons
  1. Cover
  2. Table of Contents
  3. Title Page
  4. Foreword
  5. Part I: Getting Started: Setup and Concepts
    1. Chapter 1: The Setup
      1. Installing on Windows
      2. Installing on OS X
      3. Installing on Linux
      4. The Node REPL
      5. Executing a file
      6. NPM
      7. Summary
    2. Chapter 2: Javascript: An Overview
      1. Introduction
      2. Basic JavaScript
      3. v8 JavaScript
      4. Summary
    3. Chapter 3: Blocking and Non-blocking IO
      1. With great power comes great responsibility
      2. Summary
    4. Chapter 4: Node JavaScript
      1. The global object
      2. The module system
      3. Exposing APIs
      4. Events
      5. Buffers
      6. Summary
  6. Part II: Essential Node APIs
    1. Chapter 5: CLI and FS APIs: Your First Application
      1. Requirements
      2. Writing your first program
      3. Exploring the CLI
      4. Exploring the fs module
      5. Summary
    2. Chapter 6: TCP
      1. What are the characteristics of TCP?
      2. Telnet
      3. A TCP chat program
      4. An IRC Client program
      5. Summary
    3. Chapter 7: HTTP
      1. The structure of HTTP
      2. Headers
      3. Connections
      4. A simple web server
      5. A twitter web client
      6. A superagent to the rescue
      7. Reloading HTTP servers with up
      8. Summary
  7. Part III: Web Development
    1. Chapter 8: Connect
      1. A simple website with HTTP
      2. A simple website with Connect
      3. Middleware
      4. Summary
    2. Chapter 9: Express
      1. A simple express app
      2. Settings
      3. Template engines
      4. Error handling
      5. Convenience methods
      6. Routes
      7. Middleware
      8. Organization strategies
      9. Summary
    3. Chapter 10: WebSocket
      1. AJAX
      2. HTML5 WebSocket
      3. An Echo Example
      4. Mouse cursors
      5. The Challenges Ahead
      6. Summary
    4. Chapter 11: Socket.IO
      1. Transports
      2. A chat program
      3. A DJ-by-turns application
      4. Summary
  8. Part IV: Databases
    1. Chapter 12: MongoDB
      1. Installation
      2. Accessing MongoDB: A user authentication example
      3. Introducing Mongoose
      4. A mongoose example
      5. Summary
    2. Chapter 13: MySQL
      1. node-mysql
      2. sequelize
      3. Summary
    3. Chapter 14: Redis
      1. Installing Redis
      2. The Redis Query Language
      3. Data types
      4. Redis and Node
      5. Summary
  9. Part V: Testing
    1. Chapter 15: Code Sharing
      1. What can be shared?
      2. Writing compatible JavaScript
      3. Putting it all together: browserbuild
      4. Summary
    2. Chapter 16: Testing
      1. Simple testing
      2. Expect.JS
      3. Mocha
      4. Summary

Chapter 3: Blocking and Non-blocking IO

Much of the discussion about Node.JS is centered around its capabilities to handle a lot of concurrency. In simple terms, Node is a framework that offers developers a powerful way to design networking applications that will perform really well in comparison to other mainstream solutions, provided that they understand the tradeoffs and what makes Node programs perform well.

With great power comes great responsibility

Node introduces a complexity to JavaScript that you’re probably not really used to managing much in the browser: shared-state concurrency. As a matter of fact, this complexity is also inexistent in traditional models for making web applications like Apache and mod_php or Nginx and FastCGI.

In less technical terms, in Node you have to be careful about how your callbacks modify the variables around them (state) that are currently in memory. Thus, you need to be especially careful about how you handle errors that can potentially alter this state in unexpected ways and potentially render the entire process unusable.

To fully understand this, imagine the following function, which gets executed every time the user makes a request to the URL /books. Imagine also that the “state” is a collection of books that you’ll ultimately use to return an HTML list of books.

var books = [


  , ‘Crime and punishment’


function serveBooks () {

  // I’m going to serve some HTML to the client

  var html = ‘<b>’ + books.join(‘</b><br><b>’) ...

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