Book Image

Node.js Design Patterns - Second Edition

By : Luciano Mammino, Purra, Mario Casciaro
Book Image

Node.js Design Patterns - Second Edition

By: Luciano Mammino, Purra, Mario Casciaro

Overview of this book

Node.js is a massively popular software platform that lets you use JavaScript to easily create scalable server-side applications. It allows you to create efficient code, enabling a more sustainable way of writing software made of only one language across the full stack, along with extreme levels of reusability, pragmatism, simplicity, and collaboration. Node.js is revolutionizing the web and the way people and companies create their software. In this book, we will take you on a journey across various ideas and components, and the challenges you would commonly encounter while designing and developing software using the Node.js platform. You will also discover the "Node.js way" of dealing with design and coding decisions. The book kicks off by exploring the basics of Node.js describing it's asynchronous single-threaded architecture and the main design patterns. It then shows you how to master the asynchronous control flow patterns,and the stream component and it culminates into a detailed list of Node.js implementations of the most common design patterns as well as some specific design patterns that are exclusive to the Node.js world.Lastly, it dives into more advanced concepts such as Universal Javascript, and scalability' and it's meant to conclude the journey by giving the reader all the necessary concepts to be able to build an enterprise grade application using Node.js.
Table of Contents (12 chapters)

Running CPU-bound tasks


The totalSales() API, even though expensive in terms of resources, was not affecting the ability of the server to accept concurrent requests. What we learned about the event loop in Chapter 1, Welcome to the Node.js Platform, should provide an explanation for this behavior: invoking an asynchronous operation causes the stack to unwind back to the event loop, leaving it free to handle other requests.

However, what happens when we run a long, synchronous task that never gives back the control to the event loop? This kind of task is also known as CPU-bound, because its main characteristic is that it is heavy on CPU utilization rather than being heavy on I/O operations.

Let's work immediately on an example to see how these types of task behave in Node.js.

Solving the subset sum problem

Let's now choose a computationally expensive problem to use as a base for our experiment. A good candidate is the subset sum problem that consists of deciding whether a set (or multiset) of...