socket.io-streamr

A Socket.IO streaming module that enables efficient file streaming between Socket.IO servers using various adapters. This module is particularly useful for distributed systems where file transfers need to occur across different Socket.IO instances. This module is inspired by socket.io-stream but supports redis streams.

Features

• Stream files between Socket.IO servers and clients
• Support for multiple adapters
• Progress tracking for file transfers
• Memory-efficient streaming

Supported Adapters

• [x] Redis
• [x] Redis Streams
• [ ] Mongo (test included but not tested)

Installation

npm install socket.io-streamr

Basic Usage

Server Side

const { Server } = require('socket.io');
const ss = require('socket.io-streamr');
const Redis = require('ioredis');
const { createAdapter } = require('socket.io-redis');

// Setup Socket.IO server
const io = new Server(server);

// Configure Redis adapter
const pubClient = new Redis('redis://localhost:6379');
const subClient = pubClient.duplicate();
io.adapter(createAdapter(pubClient, subClient));

// Handle file streaming
io.on('connection', (socket) => {
  const stream = ss(socket).createStream();
  
  // Emit file through Redis
  io.emit('file', stream, {
    name: 'example.txt',
    size: fileSize
  });
  
  // Pipe file to stream
  fileStream.pipe(stream);
});

Client Side

const { io } = require('socket.io-client');
const ss = require('socket.io-streamr');

const socket = io('http://localhost:3000');

ss(socket).on('file', (stream, data) => {
  // Handle incoming file stream
  let received = 0;
  
  stream.on('data', (chunk) => {
    received += chunk.length;
    const progress = (received / data.size * 100).toFixed(2);
    console.log(`Download progress: ${progress}%`);
  });
  
  // Pipe to destination
  stream.pipe(fs.createWriteStream(data.name));
});

API Reference

Server-side Methods

• ss(socket).createStream(options): Creates a new stream for file transfer
• ss(socket).emit(event, stream, data): Emits a stream with associated metadata

Client-side Methods

• ss(socket).on(event, callback): Listens for incoming streams
• stream.on('data', callback): Handles chunks of incoming data
• stream.on('end', callback): Triggered when stream ends

Note about Client and Server

Either side can be used as the source or destination of the stream. The Client and Server usage is just an example but works either way

Testing

npm install
npm test

Debugging

To see the debug logs, set the environment variable DEBUG to socket.io-streamr:* example: DEBUG=socket.io-streamr:* npm test

License

This project is licensed under the Apache License - see the LICENSE file for details.

Acknowledgments

• socket.io-stream for the original idea