Engines are of several types:
- Cache
- DB
- Storage
They are created to provide simple unified interfaces for working with different Cache/DataBase/Storage types.
For example if you want to get some item from cache you can just write:
<?php
$Cache = \cs\Cache::instance();
$item = $Cache->item;and it doesn't matter what type of cache driver is used.
Every driver directory contain files with classes (files names are the same as classes names). Each class inherits _Abstract class of the same directory. _Abstract class is, obviously, abstract and provides interface for its driver type. Some methods have realization, but may be redefined, other methods are abstract and must be defined in inherited classes in order to provide unified interface.
All drivers are located in directory core/drivers