Dig Key-Value Store

A high-performance key-value cache library with both in-memory and persistent storage, written in Rust with Node.js bindings.

Features

• Dual-layer caching with in-memory LRU cache and SQLite persistent storage
• Configurable memory limits and cleanup intervals
• Optional time-to-live (TTL) for cache entries
• Asynchronous API for Node.js
• Written in Rust for high performance

Installation

npm install dig-key-value-store

Usage

const { JsCache } = require('dig-key-value-store');

async function example() {
  // Create a new cache instance
  const cache = new JsCache({
    maxMemoryMb: 100,         // Maximum memory usage in MB
    dbPath: './cache.db',     // Path to SQLite database file
    cleanupIntervalMs: 60000  // Cleanup interval in milliseconds (1 minute)
  });

  // Set a value
  const key = 'user:123';
  const value = Buffer.from(JSON.stringify({ name: 'John', age: 30 }));
  await cache.set(key, value);

  // Set a value with TTL (time-to-live)
  await cache.set('session:456', Buffer.from('session-data'), 3600000); // 1 hour TTL

  // Get a value
  const result = await cache.get(key);
  if (result) {
    const userData = JSON.parse(result.toString());
    console.log(userData); // { name: 'John', age: 30 }
  }

  // Delete a value
  await cache.delete(key);
}

example().catch(console.error);

API

JsCache

Constructor

new JsCache(options)

Creates a new cache instance.

Parameters:

• options (Object): Configuration options
  • maxMemoryMb (number): Maximum memory usage in megabytes
  • dbPath (string): Path to the SQLite database file
  • cleanupIntervalMs (number): Cleanup interval in milliseconds

Methods

set(key, value, ttlMs)

Sets a value in the cache.

Parameters:

• key (string): The key to store the value under
• value (Buffer): The value to store
• ttlMs (number, optional): Time-to-live in milliseconds

Returns: Promise

get(key)

Gets a value from the cache.

Parameters:

• key (string): The key to retrieve

Returns: Promise<Buffer | null> - The value if found, or null if not found or expired

delete(key)

Deletes a value from the cache.

Parameters:

• key (string): The key to delete

Returns: Promise

Development

Prerequisites

• Node.js 14+
• Rust 1.56+
• SQLite development libraries

Setup

1. Install sqlx-cli with cargo:

cargo install sqlx-cli

2. Install npm dependencies:

npm install

Building

npm run build

Testing

npm test

License

MIT