Simple Cache Interface

CacheInterface.php

<?php
interface Cache
{
    /**
     * Does cache exist for the key?
     *
     * @param string $key Key value used to store cache
     *
     * @return bool
     */
    public function exists($key);

    /**
     * Get cache for the key
     *
     * @param string $key Key value used to store cache
     *
     * @return mixed
     */
    public function get($key);

    /**
     * Remove cache entry for the specified key
     *
     * @param string $key Key value used to store cache
     *
     * @return bool
     */
    public function delete($key);

    /**
     * Save data in cache using the key value provided
     *
     * @param string $key   Key value for the cache entry
     * @param mixed  $data  Value to store as a cache entry
     * @param int    $ttl   Time To live in seconds
     *
     * @return bool
     */
    public function put($key, $value, $ttl = 0);

}