How to Implement Caching with Koa

How to Implement Caching with Koa

What is Koa?

Koa is a web framework from the team behind Express that offers a smaller, more expressive, more robust foundation for APIs and web applications. Koa's use of async functions removes the need for callbacks and increases error handling. A Koa Context combines a node request and response object into a single object providing numerous helpful methods for writing APIs and web apps.

What is a Cache?

A cache is a short-term, high-speed data storage layer that stores a subset of data, enabling it to be retrieved faster than accessing it from its primary storage location. Caching allows you to reuse previously retrieved data efficiently.

Caching Support in Keyv

Caching will work in memory by default. However, users can also install a Keyv storage adapter that is initialized with a connection string or any other storage that implements the Map API.

Example - Add Cache Support Using Koa

import keyv from 'keyv';

// ...
const cache = new Keyv();
const cacheTTL = 1000 * 60 * 60 * 24; // 24 hours

app.use(async ctx => {
    // this response is already cashed if `true` is returned,
    // so this middleware will automatically serve this response from cache
    if (await keyv.get(ctx.url)) {
        return keyv.get(ctx.url);
    }

    // set the response body here
    ctx.body = 'hello world!';
    // cache the response
    await keyv.set(ctx.url, ctx.body. cacheTTL);
});