@satyajeetsahoo/cache

A flexible, production-ready caching module with support for Local (in-memory) and Redis strategies.

Why use this package?

When building scalable applications, you often start with in-memory caching but eventually need to migrate to Redis when deploying multiple server instances. This package abstracts the caching engine, allowing you to seamlessly switch between Local Memory and Redis without changing a single line of your application logic.

Features

• Unified API: Identical methods for both memory and Redis.
• Counters: Built-in atomic increments for rate limiting.
• TTL Support: Automatic expiration of stale data.

Installation

npm install @satyajeetsahoo/cache

Configuration & Strategies

Local (Memory) Strategy

Ideal for local development or single-instance deployments.

import { CacheService } from '@satyajeetsahoo/cache';
export const cache = CacheService.createCache('local');

Redis Strategy

Ideal for production multi-instance clusters.

import Redis from 'ioredis';
import { CacheService } from '@satyajeetsahoo/cache';

const redis = new Redis(process.env.REDIS_URL);
export const cache = CacheService.createCache('redis', { client: redis });

Usage Examples

1. Storing and Retrieving JSON Data

Objects are automatically serialized and deserialized.

await cache.set('user:1', { name: 'Satyajeet', role: 'admin' }, 300); // Expires in 5 minutes

const user = await cache.get('user:1');
// => { name: 'Satyajeet', role: 'admin' }

2. Rate Limiting with Counters

The increment method is atomic, making it perfect for tracking login attempts.

const attempts = await cache.increment('login:attempts:user1', 900); // 15 minute TTL
if (attempts > 5) {
  throw new Error('Too many login attempts');
}

API Reference

• set(key, value, ttlSeconds): Stores a value.
• get(key): Retrieves a parsed value.
• exists(key): Returns boolean indicating if key exists.
• increment(key, ttlSeconds): Atomically increments a counter and returns the new value.
• delete(key): Removes a key.
• clear(): Clears all cache (requires a prefix for Redis).