StoreInterface.php

<?php
/**
 * Interface that MUST be implemented by supported Cache Stores.
 *
 * @package SugiPHP.Cache
 * @author  Plamen Popov <tzappa@gmail.com>
 * @license http://opensource.org/licenses/mit-license.php (MIT License)
 */

namespace SugiPHP\Cache;

/**
 * Cache Store Interface
 */
interface StoreInterface
{
    /**
     * Stores an item in the cache for a specified period of time only if it is not already stored.
     * StoreInterface::add() is similar to StoreInterface::set(), but the operation fails if the key
     * already exists.
     *
     * @param string  $key
     * @param mixed  $value The value to be stored.
     * @param integer $ttl Time to live in seconds. 0 means to store it for a maximum time possible
     *
     * @return boolean TRUE if the value is set, FALSE on failure
     */
    public function add($key, $value, $ttl = 0);

    /**
     * Stores an item in the cache for a specified period of time.
     * StoreInterface::set() is similar to StoreInterface::add(), but the operation will not fail if
     * the key already exist.
     *
     * @param string $key
     * @param mixed $value The value to be stored.
     * @param integer $ttl Time to live in seconds. 0 means to store it for a maximum time possible
     *
     * @return boolean TRUE if the value is set, FALSE if storing failed
     */
    public function set($key, $value, $ttl = 0);

    /**
     * Retrieve an item from the cache.
     *
     * @param string $key
     *
     * @return mixed The value that was stored, or NULL if the value was not set or expired or not
     *         available for some other reason
     */
    public function get($key);

    /**
     * Determine if an item exists in the cache.
     *
     * @param string $key
     *
     * @return boolean
     */
    public function has($key);

    /**
     * Removes an item from the cache.
     *
     * @param string $key
     *
     * @return void
     */
    public function delete($key);

    /**
     * Removes all items from the cache.
     *
     * @return void
     */
    public function flush();
}