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

Reading from a file

In our discussion of file descriptors we touched on one method of opening a file, fetching a file descriptor, and ultimately pushing or pulling data through that reference. Reading files is a common operation. Sometimes managing a read buffer precisely may be necessary, and Node allows byte-by-byte control. In other cases one simply wants a no-frills stream that is simple to use.

Reading byte by byte

The method is the most low-level way Node offers for reading files., buffer, offset, length, position, callback)

Files are composed of ordered bytes, and these bytes are addressable by their position, relative to the beginning of in the file (position zero [0]). Once we have a file descriptor fd, we can begin to read length number of bytes and insert those into a Buffer object buffer, insertion beginning at a given buffer offset. For example, to copy the 8366 bytes beginning at position 309 of readable file fd into a buffer beginning at an offset of 100, we...