How NodeJS Works

A short overview of how NodeJS actually works for CNTU students.

Transcript

1. How NodeJS Works? Volodymyr Rudyi
2. Intro CEO @ AgileVision Software Engineer Studied at CNTU some time ago ;)
3. A bit of JavaScript history • Created in 1993 • First standard in 1996 • Latest standard in 2017 • Used on clients and servers
4. What’s NodeJS then?
5. Execution environments 101 • Allows executing JavaScript code • Works on a particular platform/set of platforms • Provides an additional API to interact with the platform
7. Other well-known execution environments •Web browsers
8. NodeJS Provides tools for • Interaction with file systems (fs) • Console (console.log) • Timer (setTimeout) • Debugging and profiling (Inspector/Chrome Dev Tools) • Thousands of other stuff • These features are called NodeJS API
9. APIs are written in
10. How it works? console.log() C++ code NodeJS
11. Fun fact NodeJS doesn’t know how to execute JavaScript
12. … but V8 knows It’s like little Yoda inside a spaceship…
13. V8 • Not a Mustang GT • A JavaScript Engine developed by Google • Written in C++ • Knows how to parse and execute JavaScript code • Knows nothing about browsers, files, operating systems
14. How it really works then? JavaScript Code API (Written in C+++) NodeJS V8
15. Summary • Programmer writes JavaScript code and passes it to the NodeJS(Execution Environment) • Execution environment passes the code to the V8 engine • V8 engine parses code and executes it • Each time API is used, V8 calls the corresponding code from the execution environment (using so-called “bindings”)
16. Idea • It’s possible to create your own custom execution environment • It’s should be easy
17. Options Embed V8 Embed Mozilla Rhino
18. Embedding V8 - Pros • Wide set of features • Performance • Inspection/analysis using Chrome Dev Tools protocol • It’s native
19. Embedding V8 - Cons • You need to know C++ • It’s native
20. Embedding Rhino - Pros • Java-based API • Can be almost instantly embedded to some platforms, like Android • Non-native code running in JVM
21. Embedding Rhino - Cons • Java-based API • Won’t work on platforms like iOS
22. Questions?