Here is the updated README for sysdb, reflecting the final minimal API (get() + set() only), with no commit() and no direct data access.

sysdb

A lightweight, in-memory JSON database for Node.js designed for speed and simplicity. Intended for single-process environments only. Clustered or multi-process usage is not supported.

sysdb keeps all data in memory and persists snapshots to disk asynchronously. Reads are synchronous and fast; writes are debounced and persisted in the background.

Optimized for smaller datasets, typically up to ~100,000 records.

Features

• Mongo-style Queries: $gt, $lt, $gte, $lte, $ne, $in, $nin, $regex
• In-memory Authority: All reads operate on in-memory data
• Atomic Persistence: Snapshots written via .tmp + rename
• Date Support: Automatic normalization and comparison of Date values
• Pagination: Built-in limit and skip
• Minimal API: Only get() and set()

Installation

npm i sysdb

Usage

var sysdb = require('sysdb')

// Single database / collection
var db = sysdb('./sysdb.json')

var users = db.get({ type: 'user' })

// Multiple logical tables
var db = {
  users: sysdb('./users.json'),
  projects: sysdb('./projects.json'),
}

var users = db.users.get({})
var projects = db.projects.get({})

Usage Examples

1. Inserting Data

Passing a single object inserts a new document. A UUID id is generated automatically if missing.

await db.set({
  name: 'Project Alpha',
  status: 'pending',
  priority: 1,
  createdAt: new Date()
})

2. Querying with Operators

// Find high priority tasks
var tasks = db.get({
  priority: { $gte: 5 },
  status: { $ne: 'archived' }
})

// Regex and array operators
var results = db.get({
  name: { $regex: /^Project/i },
  tags: { $in: ['urgent', 'active'] }
})

3. Updating Data

// Update all pending tasks
await db.set({ status: 'pending' }, { status: 'active' })

// Update by ID
await db.set({ id: 'some-uuid' }, { progress: 100 })

4. Deleting Data

// Delete a single record
await db.set({ id: 'some-uuid' }, null)

// Delete all completed tasks
await db.set({ status: 'completed' }, null)

// Clear entire database
await db.set({}, null)

5. Pagination

var page = db.get({ type: 'log' }, {
  limit: 10,
  skip: 10
})

Persistence Model

• Data is stored in memory
• Writes are debounced (5 ms) and snapshotted to disk
• Persistence is eventual
• On process exit before snapshot, recent writes may be lost

There is no explicit flush or commit operation.

API Reference

| Method | Description | | ----------------------- | ------------------------------------------------------------- | | get(query, [options]) | Returns matching documents. Supports { limit, skip, sort }. | | set(query, [values]) | Insert, update, or delete documents. |

Limitations

• Single process only
• No multi-process safety
• No transactional guarantees
• No live reload of external file changes

For multi-process or crash-durable use cases, use unitdb instead.

License

ISC.

Acknowledgements

Created by Vidar Eldøy, Tekki AS.