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V8 Engine, libuv, C++ bindings. Single-threaded event loop model. Node.js vs Deno vs Bun. Development history, use cases. node --inspect, V8 flags.

Node.js Core: From Basics to Advanced

Part 1: Node.js Internals

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1. What is Node.js?

Node.js is a JavaScript runtime built on Chrome's V8 Engine, allowing to run JavaScript on the server side. Launched in 2009 by Ryan Dahl, Node.js has completely changed the way the world thinks about JavaScript.

Ingredients	Role
V8 Engine	JS compilation → machine code, memory management
libuv	Event loop, async I/O, thread pool, cross-platform
C++ Bindings	Connect JS to system-level APIs (fs, net, crypto)
Node.js API	JavaScript APIs (http, paths, events, streams…)

2. Node.js architecture

┌─────────────────────────┐
│     Your JavaScript     │
├─────────────────────────┤
│     Node.js APIs        │
│  (http, fs, crypto…)    │
├─────────────────────────┤
│    C++ Bindings         │
├──────────┬──────────────┤
│  V8      │    libuv     │
│  Engine  │  (event loop)│
└──────────┴──────────────┘
│       Operating System       │

3. Node.js vs Deno vs Bun

Features	Node.js	Deno	Bun
Engine	V8	V8	JavaScriptCore
Language	C++	Rust	Zig
TypeScript	--experimental-strip-types	Native	Native
Package Manager	npm/pnpm/yarn	deno add	bun install
Ecosystem	Largest (3M+ packages)	npm compatible	npm compatible
Security	Full access	Permissions	Full access

4. Installation & Setup

# Cài Node.js qua nvm
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.0/install.sh | bash
nvm install 22
nvm use 22
node --version  # v22.x.x

# Cài pnpm
corepack enable
corepack prepare pnpm@latest --activate

# Khởi tạo project
mkdir my-node-project && cd my-node-project
pnpm init

5. V8 Engine Flags

# Xem tất cả V8 flags
node --v8-options | head -50

# Giới hạn memory
node --max-old-space-size=4096 app.js

# Inspect debugger
node --inspect app.js        # Chrome DevTools tại chrome://inspect
node --inspect-brk app.js    # Break ở dòng đầu tiên

# V8 profiling
node --prof app.js
node --prof-process isolate-*.log > processed.txt

6. Hello World & REPL

// hello.ts
const message: string = 'Hello from Node.js!'
console.log(message)
console.log(`Node.js version: ${process.version}`)
console.log(`Platform: ${process.platform}`)
console.log(`Architecture: ${process.arch}`)
console.log(`PID: ${process.pid}`)
console.log(`Memory: ${JSON.stringify(process.memoryUsage())}`)

# Chạy TypeScript trực tiếp (Node.js 22+)
node --experimental-strip-types hello.ts

# Hoặc dùng tsx
npx tsx hello.ts