QDB: Real-time Queuing Database

QDB is a lightweight, local-first Real-time Queuing Database designed to be a "Firebase-lite" for your Node.js projects. It combines a JSON-based database, a robust job queue, real-time WebSocket subscriptions, and an admin UI into a single zero-dependency (almost) package.

Features

• Store: Simple JSON-based tables with SQL-like queries (powered by SQLite).
• Queue: Built-in job queue with atomic enqueue, dequeue, ack, and fail operations.
• Real-time: WebSocket subscriptions to tables or specific topics. No polling required.
• Data Lifetime: Auto-expire data with a built-in TTL system.
• Migration: Tools to migrate schema and archive old data to keep things fast.
• UI Hosting: Serve your own React-based Admin UI directly from the database server.
• CLI: Native CLI for management (qdb init, qdb migrate, qdb start).

Installation

npm install queuedb

Quick Start (CLI)

Initialize and run QDB in seconds:

# Initialize a new database
npx qdb init my_project

# Start the server
npx qdb start my_project --port 3000

Core Usage (SDK)

import { QDB, QDBServer } from 'queuedb';

// 1. Setup Database
const db = new QDB("my_project", {});
await db.init(); // Creates tables and queue system

// 2. Queue Operations
await db.enqueue('email_notifications', { userId: 1, type: 'welcome' });

// 3. Worker / Consumer
const job = await db.dequeue('worker_client_1');
if (job.success && job.data) {
    console.log("Processing:", job.data);
    // ... work ...
    await db.ack(job.data.id);
}

// 4. Start Server for Realtime Access
const server = new QDBServer("main", { port: 3000 });
server.mountDb(db);
server.listen();

Real-time Subscriptions (WebSocket)

Clients can connect via WebSocket to receive updates instantly.

Connect: ws://localhost:3000

Subscribe: Send a JSON message:

{
    "type": "subscribe",
    "method": "GET",
    "route": "/my_project/users"
}

Receive Updates: You will receive a message whenever data changes in the subscribed route.

Admin UI

QDB can host a web-based Admin UI (e.g., a React app). By default, the middleware serves files from dist/ui at the /admin route.

CLI Commands

• qdb init <name>: Create new DB structure.
• qdb start <name>: Start the QDB server.
• qdb migrate <name>: Run schema migrations.
• qdb archive <name> <table> <days>: Move old data to archive files.

License

MIT