How NodeJS Works

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
6. None

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?