Drupal 8 Cache API

Get the default cache bin

$cache = \Drupal::cache();

To get a particular cache bin (here 'render'):

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

Save / Cache itmes

Example:

$my_object = 'A stdClass';

Drupal::cache()->set('my_cache_key', $my_object, CacheBackendInterface::CACHE_PERMANENT, array('my_first_tag', 'my_second_tag'));

Read a cached item

$cache = \Drupal::cache()->get('my_cache_key');

Cache remove and invalidation

You can remove cache manually using following methods:

invalidate(), invalidateMultiple(), invalidateAll(), delete(), deleteMultiple() or deleteAll();

And also using cache tags

Example: To invalidate cach with tags 'node:5' and/or 'my_first_tag'

\Drupal\Core\Cache\Cache::invalidateTags(array('node:5', 'my_first_tag'));

Delete Cache (by CID)

$cids = ['cid1', 'cid2',];

\Drupal::cache()->delete($cids);

Cache contex

https://www.drupal.org/docs/8/api/cache-api/cache-contexts