@prairielearn/cache

Utilities to help connect to and store information in a cache. This package does not load configurations directly. Instead, configs should be passed in when the package is initialized upon loading the application. Then, the package can be used in the throughout the application to interact with the cache.

Usage

First, you will need to initialize the library with the cache type that you are intending to use, a prefix that will be the start of all of your cache keys, and optionally, a Redis server URL if that is the cache type being used:

import { cache } from '@prairielearn/cache';

await cache.init({
  type: 'redis',
  keyPrefix: 'my-app:',
  redisUrl: 'redis://localhost:6379/',
});

Alternatively, you can create new instances of the Cache class instead of using the global cache object:

import { Cache } from '@prairielearn/cache';

const myCache = new Cache();

await myCache.init({
  type: 'redis',
  keyPrefix: 'my-app:',
  redisUrl: 'redis://localhost:6379/',
});

After initializing, you can use set, get, del, reset or close functions to interact with the cache. Note that set, get, and del have required arguments. Calling set will require the intended KEY, VALUE, and length of time to store the data (in milliseconds). Calling get or del will require the KEY for the intended result.

The following example will store foo: bar for 10 minutes:

await cache.set('foo', 'bar', 600000);

The following example will use the key foo to retrieve the value bar:

await cache.get('foo');
// returns bar

The following example will use the key foo to delete the key value pair foo: bar:

await cache.del('foo');

Using reset() will clear the currently stored data in the cache. Using close() will disable the currently used cache and, if using Redis, close the connection.