Exploring the Cache API in Drupal 8

Drupal 8 comes with many improvements over its predecessor we have grown to both love and hate. Next to prominent systems such as Views in core, configuration management or a useful translation service, there are also less known changes but that are equally important to know and use. One such improvement has been the cache API that solves many performance problems we have in Drupal 7.

In this article, I want to shine a bit of light over the new cache API. To this end, we are going to look at how we can use it in our custom modules as we are encouraged to do so much more in Drupal 8.

Additionally, I have prepared a little demonstration in the shape of a module you can install for testing the impact of the cache API. It’s a simple page that in its rendering logic makes an external API call (to a dummy JSON endpoint) and caches its results. The page then displays the actual time it takes for this to happen, contrasting the external call time vs. the cached version time.

The new cache API

Bins

The new cache API (with the default DatabaseBackend storage) is stored in multiple bins which map to tables that start with the prefix cache_. When interacting with the cache, we always start by requesting a cache bin:

$cache = \Drupal::cache(); 

Where $cache will be an instance of the DatabaseBackend object that represents the default bin (cache_default). To request a particular bin we pass in the name in the constructor:

$render_cache = \Drupal::cache('render'); 

Where $render_cache will represent the render cache bin (which is new in Drupal 8 and is supposed to improve render performance across the board).

Continue reading %Exploring the Cache API in Drupal 8%

by Daniel Sipos via SitePoint