Book Image

Mastering Node.js

By : Sandro Pasquali
Book Image

Mastering Node.js

By: Sandro Pasquali

Overview of this book

Node.js is a modern development stack focused on providing an easy way to build scalable network software. Backed by a growing number of large companies and a rapidly increasing developer base, Node is revolutionizing the way that software is being built today. Powered by Google's V8 engine and built out of C++ modules, this is a JavaScript environment for the enterprise.Mastering Node.js will take the reader deep into this exciting development environment. Beginning with a comprehensive breakdown of its innovative non-blocking evented design, Node's structure is explained in detail, laying out how its blazingly fast I/O performance simplifies the creation of fast servers, scalable architectures, and responsive web applications.Mastering Node.js takes you through a concise yet thorough tour of Node's innovative evented non-blocking design, showing you how to build professional applications with the help of detailed examples.Learn how to integrate your applications with Facebook and Twitter, Amazon and Google, creating social apps and programs reaching thousands of collaborators on the cloud. See how the Express and Path frameworks make the creation of professional web applications painless. Set up one, two, or an entire server cluster with just a few lines of code, ready to scale as soon as you're ready to launch. Move data seamlessly between databases and file systems, between clients, and across network protocols, using a beautifully designed, consistent, and predictable set of tools.Mastering Node.js contains all of the examples and explanations you'll need to build applications in a short amount of time and at a low cost, running on a scale and speed that would have been nearly impossible just a few years ago.
Table of Contents (20 chapters)
Mastering Node.js
About the Author
About the Reviewers

Implementing callbacks

In keeping with the typical pattern of a Node program, add-ons also implement the notion of callbacks. As one might expect in a Node program, a C++ add-on performing an expensive and time-consuming operation should comprehend the notion of asynchronously executing functions.

The following code will expose a method that will pass back the current system time to any callback it is sent:

#include <node.h>
#include <ctime>

using namespace v8;

Handle<Value> GetTime(const Arguments& args) {
  HandleScope scope;

  Local<Function> cb = Local<Function>::Cast(args[0]);
  const unsigned argc = 1;
  time_t stamp = time(0);
  Local<Value> argv[argc] = { 
  cb->Call(Context::GetCurrent()->Global(), argc, argv);

  return scope.Close(Undefined());

void Init(Handle<Object> exports, Handle<Object> module) {

NODE_MODULE(callback, Init)

Here we include the ctime standard library, using its time method when setting up our GetTime handle. The magic happens within this handle, where your function argument is properly bound and called.

Once you have created your binding file and compiled everything, go ahead and run your callback module:

var timeNow = require('./build/Release/callback');

//  1481315296

Beginning with these tools you can start developing some equally simple add-ons, eventually moving into deeper territory.