MemcachedSessionHandler.php

<?php


/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace Symfony\Component\HttpFoundation\Session\Storage\Handler;


/**
 * Memcached based session storage handler based on the Memcached class
 * provided by the PHP memcached extension.
 *
 * @see https://php.net/memcached
 *
 * @author Drak <drak@zikula.org>
 */
class MemcachedSessionHandler extends AbstractSessionHandler {
    
    /**
     * Time to live in seconds.
     */
    private int|\Closure|null $ttl;
    
    /**
     * Key prefix for shared environments.
     */
    private string $prefix;
    
    /**
     * Constructor.
     *
     * List of available options:
     *  * prefix: The prefix to use for the memcached keys in order to avoid collision
     *  * ttl: The time to live in seconds.
     *
     * @throws \InvalidArgumentException When unsupported options are passed
     */
    public function __construct(\Memcached $memcached, array $options = []) {
        if ($diff = array_diff(array_keys($options), [
            'prefix',
            'expiretime',
            'ttl',
        ])) {
            throw new \InvalidArgumentException(\sprintf('The following options are not supported "%s".', implode(', ', $diff)));
        }
        $this->ttl = $options['expiretime'] ?? $options['ttl'] ?? null;
        $this->prefix = $options['prefix'] ?? 'sf2s';
    }
    public function close() : bool {
        return $this->memcached
            ->quit();
    }
    protected function doRead(string $sessionId) : string {
        return $this->memcached
            ->get($this->prefix . $sessionId) ?: '';
    }
    public function updateTimestamp(string $sessionId, string $data) : bool {
        $this->memcached
            ->touch($this->prefix . $sessionId, $this->getCompatibleTtl());
        return true;
    }
    protected function doWrite(string $sessionId, string $data) : bool {
        return $this->memcached
            ->set($this->prefix . $sessionId, $data, $this->getCompatibleTtl());
    }
    private function getCompatibleTtl() : int {
        $ttl = ($this->ttl instanceof \Closure ? ($this->ttl)() : $this->ttl) ?? \ini_get('session.gc_maxlifetime');
        // If the relative TTL that is used exceeds 30 days, memcached will treat the value as Unix time.
        // We have to convert it to an absolute Unix time at this point, to make sure the TTL is correct.
        if ($ttl > 60 * 60 * 24 * 30) {
            $ttl += time();
        }
        return $ttl;
    }
    protected function doDestroy(string $sessionId) : bool {
        $result = $this->memcached
            ->delete($this->prefix . $sessionId);
        return $result || \Memcached::RES_NOTFOUND == $this->memcached
            ->getResultCode();
    }
    public function gc(int $maxlifetime) : int|false {
        // not required here because memcached will auto expire the records anyhow.
        return 0;
    }
    
    /**
     * Return a Memcached instance.
     */
    protected function getMemcached() : \Memcached {
        return $this->memcached;
    }

}