Understanding Node.js in Depth

This book examines the internal characteristics and structure of Node.js from several angles. Starting with an introduction to Node.js, it successively reveals the module mechanism, the implementation principles of asynchronous I/O, asynchronous programming styles, memory control, and the details of the binary data Buffer, and explains the basics of network programming in Node.js, web development, inter-process communication and message passing, unit testing, and the things to watch for when building products with Node.js. Appendices cover installing Node.js, debugging, coding conventions, and the NPM registry. The author, Piao Ling, is an active evangelist in China's Node.js community; the book does not stop at API usage but digs into source code and runtime mechanisms to explain why things are designed as they are—for example, the relationship between the event loop, observers, request objects, and callback execution; the loading and compiling flow of CommonJS modules; and the writing and loading of C/C++ addons. The language is plain and the book is rich in diagrams and sample code, and many Chinese developers regard it as a classic introduction to Node.js internals. Note that the book was written in 2013, based on the Node.js version and ecosystem of the time; some APIs, NPM usage, and engineering practices have since been updated, so read it alongside current official documentation.