https://github.com/kryptonbd/realtime-in-js
Implementing polling, HTTP/2, WebSockets, and Socket.IO for real-time communication using Javascript
https://github.com/kryptonbd/realtime-in-js
chat http2 javascript polling realtime realtime-chat socket-io websocket
Last synced: 4 months ago
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Implementing polling, HTTP/2, WebSockets, and Socket.IO for real-time communication using Javascript
- Host: GitHub
- URL: https://github.com/kryptonbd/realtime-in-js
- Owner: KryptonBD
- Created: 2025-06-14T12:04:18.000Z (7 months ago)
- Default Branch: master
- Last Pushed: 2025-06-14T12:25:43.000Z (7 months ago)
- Last Synced: 2025-09-09T04:44:12.684Z (4 months ago)
- Topics: chat, http2, javascript, polling, realtime, realtime-chat, socket-io, websocket
- Language: JavaScript
- Homepage:
- Size: 36.1 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
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README
# Real-time Communication in JavaScript
A comprehensive study of real-time web communication methods through progressive JavaScript implementation of chat applications.
## Overview
This repository demonstrates four fundamental approaches to real-time web communication, each building upon the previous to illustrate the evolution of techniques and trade-offs in modern web development. Each implementation serves as both a working example and educational resource.
## Architecture Progression
```
HTTP Polling → HTTP/2 Streaming → WebSocket Protocol → WebSocket Abstraction
↓ ↓ ↓ ↓
Basic Timing → Server Push → Bidirectional Protocol → Production Library
```
## Implementation Details
### 1. Polling Implementation
**Directory**: `01. polling/`
Demonstrates traditional HTTP polling with two distinct approaches:
- `setTimeout` recursive polling pattern
- `requestAnimationFrame` based polling for improved resource management
**Core Concepts:**
- Request/response cycle fundamentals
- Client-side timing mechanisms
- Exponential backoff for error handling
- Browser resource optimization
**Use Cases:** Legacy system integration, simple requirements, universal compatibility
---
### 2. HTTP/2 Streaming
**Directory**: `02. http2/`
Leverages HTTP/2's multiplexing capabilities for server-sent events:
- Persistent connection management
- Server-initiated data streaming
- SSL/TLS requirement handling
**Core Concepts:**
- HTTP/2 stream multiplexing
- Server-sent events protocol
- Connection lifecycle management
- HTTPS certificate handling
**Use Cases:** Modern web applications, unidirectional real-time data, REST API enhancement
---
### 3. Raw WebSocket Implementation
**Directory**: `03. websocket-raw/`
Ground-up WebSocket protocol implementation without external libraries:
- Custom handshake protocol handling
- Frame parsing and message encoding
- Connection state management
- Binary protocol implementation
**Core Concepts:**
- WebSocket handshake mechanics
- Frame structure and masking
- Opcode handling for different message types
- Connection upgrade process
**Use Cases:** Protocol understanding, custom implementations, performance optimization
---
### 4. Socket.IO Integration
**Directory**: `04. websocket-socket.io/`
Production-ready implementation using Socket.IO:
- Automatic transport selection
- Built-in reconnection strategies
- Event-driven communication patterns
- Fallback mechanism handling
**Core Concepts:**
- Abstraction layer benefits
- Event-driven architecture
- Automatic failover mechanisms
- Production deployment considerations
**Use Cases:** Production applications, rapid development, cross-browser compatibility
## Technical Comparison
| Implementation | Latency | Complexity | Server Resources | Development Time |
| ----------------- | ----------- | ---------- | ---------------- | ---------------- |
| **Polling** | 1-5 seconds | Low | High | Short |
| **HTTP/2** | <100ms | Medium | Medium | Medium |
| **Raw WebSocket** | <50ms | High | Low | Long |
| **Socket.IO** | <50ms | Low | Low | Short |
## Development Setup
Each project includes independent setup instructions. General requirements:
```bash
# Project-specific dependencies
cd [project-directory]
npm install
npm run dev
```
**HTTP/2 specific requirements:**
```bash
# SSL certificate generation
openssl req -new -newkey rsa:2048 -nodes -keyout key.pem -out csr.pem
openssl x509 -req -days 365 -in csr.pem -signkey key.pem -out server.crt
```
## Learning Objectives
### Fundamental Concepts
- **Connection Management**: Understanding persistent vs ephemeral connections
- **Protocol Mechanics**: HTTP upgrade process and WebSocket handshake
- **Error Handling**: Network failures, timeouts, and recovery strategies
- **Resource Optimization**: CPU usage, memory management, and network efficiency
### Advanced Topics
- **Transport Selection**: Choosing appropriate real-time communication method
- **Scalability Considerations**: Connection limits and server architecture
- **Security Implications**: CORS, authentication, and data validation
- **Performance Optimization**: Minimizing latency and maximizing throughput
## Project Structure
```
real-time-communication/
├── 01. polling/
│ ├── frontend/
│ ├── backend/
│ └── README.md
├── 02. http2/
│ ├── frontend/
│ ├── backend/
│ └── README.md
├── 03. websocket-raw/
│ ├── frontend/
│ ├── backend/
│ └── README.md
├── 04. websocket-socket.io/
│ ├── frontend/
│ ├── backend/
│ └── README.md
└── README.md
```
## Future Exploration
### WebRTC Implementation
WebRTC enables peer-to-peer communication directly between browsers, bypassing server infrastructure for data transfer. This implementation would explore direct browser-to-browser data channels, ICE candidate exchange, and STUN/TURN server integration. Use cases include gaming, file sharing, and video conferencing where low latency and reduced server load are critical.