StudipRedisCache.class.php

<?php
/**
 * Cache implementation using redis.
 *
 * @author      Jan-Hendrik Willms <tleilax+studip@gmail.com>
 * @license     GPL2 or any later version
 * @package     studip
 * @subpackage  cache
 * @since       Stud.IP 5.0
 */
class StudipRedisCache implements StudipCache
{
    use StudipCacheKeyTrait;

    private $redis;

    /**
     * @return string A translateable display name for this cache class.
     */
    public static function getDisplayName(): string
    {
        return _('Redis');
    }

    /**
     * Construct a cache instance.
     *
     * @param string $hostname Hostname of redis server
     * @param int    $port     Port of redis server
     * @param string $auth     Optional auth token/password
     */
    public function __construct($hostname, $port, string $auth = '')
    {
        if (!extension_loaded('redis')) {
            throw new Exception('Redis extension missing.');
        }

        $this->redis = new Redis();
        $status = $this->redis->connect($hostname, $port, 1);

        if (!$status) {
            throw new Exception('Could not add cache.');
        }

        if ($auth !== '') {
            $this->redis->auth($auth);
        }
    }

    /**
     * Returns the instance of the redis server connection.
     *
     * @return Redis instance
     */
    public function getRedis()
    {
        return $this->redis;
    }

    /**
     * Expire item from the cache.
     *
     * Example:
     *
     *   # expires foo
     *   $cache->expire('foo');
     *
     * @param   string $arg a single key.
     */
    public function expire($arg)