node-cache-plus

node-cache-plus is a wrapper around the popular library node-cache with additional features such as tag-based invalidation, factory functions, and other helpers for in-memory caching in Node.js applications.

Installation

To install node-cache-plus, use your preferred package manager:

npm install node-cache-plus

Usage

node-cache-plus is a drop-in replacement for node-cache. It provides the same API as node-cache with additional features. Refer to the node-cache documentation for more information on the basic usage and initialisation options.

TypeDoc reference is available here.

Basic Usage

import { Cache } from "node-cache-plus";

const cache = new Cache();

// Set a value with a TTL of 60 seconds
cache.set("key", "value", 60);

// Get the value
const value = cache.get("key");
console.log(value); // Output: "value"

// Delete the value
cache.del("key");

Tag-based Invalidation

Invalidate a single tag

invalidateTag method invalidates all keys with a specific tag.

// Set values with tags
cache.set("key1", "value1", 60, ["tag1"]);
cache.set("key2", "value2", 60, ["tag2"]);
cache.set("key3", "value3", 60, ["tag1", "tag2"]);

// Invalidate all keys with a specific tag
cache.invalidateTag("tag1"); // i.e. Invalidates keys "key1" and "key3"

cache.get("key1"); // Output: undefined
cache.get("key2"); // Output: "value2"
cache.get("key3"); // Output: undefined

Invalidate Intersection of Tags

invalidateTagsIntersection method invalidates keys that have all specified tags.

// Set values with tags
cache.set("key1", "value1", 60, ["tag1"]);
cache.set("key2", "value2", 60, ["tag2"]);
cache.set("key3", "value3", 60, ["tag1", "tag2"]);

// Invalidate keys that have all specified tags
cache.invalidateTagsIntersection(["tag1", "tag2"]); // i.e. Invalidates key "key3"

cache.get("key1"); // Output: "value1"
cache.get("key2"); // Output: "value2"
cache.get("key3"); // Output: undefined

Invalidate Union of Tags

invalidateTagsUnion method invalidates keys that have at least one of the specified tags.

// Set values with tags
cache.set("key1", "value1", 60, ["tag1"]);
cache.set("key2", "value2", 60, ["tag2"]);
cache.set("key3", "value3", 60, ["tag1", "tag2"]);

// Invalidate keys that have at least one of the specified tags
cache.invalidateTagsUnion(["tag1", "tag2"]); // i.e. Invalidates all keys

cache.get("key1"); // Output: undefined
cache.get("key2"); // Output: undefined
cache.get("key3"); // Output: undefined

withCache Helper Function

import { withCache } from "node-cache-plus";

async function fetchData(param: string): Promise<string> {
  return new Promise((resolve) => {
    setTimeout(() => {
      resolve(`data_${param}`);
    }, 500);
  });
}

const cachedFetchData = withCache(fetchData, { ttl: 600, tags: ["data"] });

const data = await cachedFetchData("param1");
console.log(data); // Output: "data_param1"

Note: This function uses the default cache, see details in the Configuring Default Cache section below. You can also pass a custom cache instance as a prop to the withCache helper

cachedCall Helper Function

import { cachedCall } from "node-cache-plus";

async function fetchData(param: string): Promise<string> {
  return new Promise((resolve) => {
    setTimeout(() => {
      resolve(`data_${param}`);
    }, 500);
  });
}

const data = await cachedCall(
  fetchData,
  { ttl: 600, tags: ["data"] },
  "param1"
);
console.log(data); // Output: "data_param1"

Note: This function uses the default cache, see details in the Configuring Default Cache section below. You can also pass a custom cache instance as a prop to the cachedCall helper

Configuring Default Cache

The helper functions withCache and cachedCall use a default cache instance. You can configure the default cache instance by using theconfigureDefaultCache function.

import { configureDefaultCache, getDefaultCache } from "node-cache-plus";

// Configure the default cache with custom options
configureDefaultCache({ stdTTL: 100, checkperiod: 120 });

// Get the default cache instance
const defaultCache = getDefaultCache();

// Use the default cache instance
defaultCache.set("key", "value", 60);
const value = defaultCache.get("key");
console.log(value); // Output: "value"