InMemoryCache

InMemoryCache is a Cache implementation backed by an in-memory SQLite database (via Node.js built-in node:sqlite). Data does not survive process restarts.

import { InMemoryCache } from "@farbenmeer/tag-based-cache/in-memory-cache";

Constructor

new InMemoryCache()

No arguments required. Creates an in-memory SQLite database and starts automatic garbage collection for expired entries.

Usage

const cache = new InMemoryCache();

await cache.set({
  key: "book:1",
  data: { title: "Dune" },
  ttl: 300,
  tags: ["books", "book:1"],
});

const entry = await cache.get("book:1");
// { data: { title: "Dune" }, attachment: null }

// Invalidate by tag
await cache.delete(["book:1"]);

Garbage Collection

Expired entries are cleaned up automatically on a periodic timer. The interval adapts based on how many expired entries are found:

• Starts at 5 seconds.
• Decreases (down to 5s minimum) when many expired entries are found.
• Increases (up to 5 minutes maximum) when few expired entries are found.

When to Use

• Development and testing.
• Single-process production deployments where persistence is not needed.
• Scenarios where you want the fastest possible reads/writes with no I/O overhead.