# MemcachedSessionHandler

class MemcachedSessionHandler extends AbstractSessionHandler

Memcached based session storage handler based on the Memcached class provided by the PHP memcached extension.

## Methods

`public` | `` | `open($savePath, $sessionName)` | {@inheritdoc} | from AbstractSessionHandler
`protected` | `string` | `doRead(string $sessionId)` | No description |
`protected` | `bool` | `doWrite(string $sessionId, string $data)` | No description |
`protected` | `bool` | `doDestroy(string $sessionId)` | No description |
`public` | `` | `validateId($sessionId)` | {@inheritdoc} | from AbstractSessionHandler
`public` | `` | `read($sessionId)` | {@inheritdoc} | from AbstractSessionHandler
`public` | `` | `write($sessionId, $data)` | {@inheritdoc} | from AbstractSessionHandler
`public` | `` | `destroy($sessionId)` | {@inheritdoc} | from AbstractSessionHandler
`public` | `` | `__construct(Memcached $memcached, array $options = array())` | Constructor. |
`public` | `` | `close()` | {@inheritdoc} |
`public` | `` | `updateTimestamp($sessionId, $data)` | {@inheritdoc} |
`public` | `` | `gc($maxlifetime)` | {@inheritdoc} |
`protected` | `Memcached` | `getMemcached()` | Return a Memcached instance. |

## Details

in AbstractSessionHandler at line 32

### `open()`

`public open($savePath, $sessionName)`

{@inheritdoc}

#### Parameters

| `$savePath` |
| `$sessionName` |

at line 73

### `doRead()`

`protected string doRead(string $sessionId)`

#### Parameters

`string` | `$sessionId` |

#### Return Value

`string` |

at line 91

### `doWrite()`

`protected bool doWrite(string $sessionId, string $data)`

#### Parameters

`string` | `$sessionId` |
`string` | `$data` |

#### Return Value

`bool` |

at line 99

### `doDestroy()`

`protected bool doDestroy(string $sessionId)`

#### Parameters

`string` | `$sessionId` |

#### Return Value

`bool` |

in AbstractSessionHandler at line 67

### `validateId()`

`public validateId($sessionId)`

{@inheritdoc}

#### Parameters

| `$sessionId` |

in AbstractSessionHandler at line 78

### `read()`

`public read($sessionId)`

{@inheritdoc}

#### Parameters

| `$sessionId` |

in AbstractSessionHandler at line 101

### `write()`

`public write($sessionId, $data)`

{@inheritdoc}

#### Parameters

| `$sessionId` |
| `$data` |

in AbstractSessionHandler at line 118

### `destroy()`

`public destroy($sessionId)`

{@inheritdoc}

#### Parameters

| `$sessionId` |

at line 48

### `__construct()`

`public __construct(Memcached $memcached, array $options = array())`

Constructor.

List of available options: * prefix: The prefix to use for the memcached keys in order to avoid collision * expiretime: The time to live in seconds.

#### Parameters

`Memcached` | `$memcached` | A \Memcached instance
`array` | `$options` | An associative array of Memcached options

#### Exceptions

InvalidArgumentException | When unsupported options are passed

at line 65

### `close()`

`public close()`

{@inheritdoc}

at line 81

### `updateTimestamp()`

`public updateTimestamp($sessionId, $data)`

{@inheritdoc}

#### Parameters

| `$sessionId` |
| `$data` |

at line 109

### `gc()`

`public gc($maxlifetime)`

{@inheritdoc}

#### Parameters

| `$maxlifetime` |

at line 120

### `getMemcached()`

`protected Memcached getMemcached()`

Return a Memcached instance.

#### Return Value

`Memcached` |

## Source code

    <?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 http://php.net/memcached
     *
     * @author Drak <drak@zikula.org>
     */
    class MemcachedSessionHandler extends AbstractSessionHandler
    {
        private $memcached;

        /**
         * @var int Time to live in seconds
         */
        private $ttl;

        /**
         * @var string Key prefix for shared environments
         */
        private $prefix;

        /**
         * Constructor.
         *
         * List of available options:
         *  * prefix: The prefix to use for the memcached keys in order to avoid collision
         *  * expiretime: The time to live in seconds.
         *
         * @param \Memcached $memcached A \Memcached instance
         * @param array      $options   An associative array of Memcached options
         *
         * @throws \InvalidArgumentException When unsupported options are passed
         */
        public function __construct(\Memcached $memcached, array $options = array())
        {
            $this->memcached = $memcached;

            if ($diff = array_diff(array_keys($options), array('prefix', 'expiretime'))) {
                throw new \InvalidArgumentException(sprintf(
                    'The following options are not supported "%s"', implode(', ', $diff)
                ));
            }

            $this->ttl = isset($options['expiretime']) ? (int) $options['expiretime'] : 86400;
            $this->prefix = isset($options['prefix']) ? $options['prefix'] : 'sf2s';
        }

        /**
         * {@inheritdoc}
         */
        public function close()
        {
            return true;
        }

        /**
         * {@inheritdoc}
         */
        protected function doRead($sessionId)
        {
            return $this->memcached->get($this->prefix.$sessionId) ?: '';
        }

        /**
         * {@inheritdoc}
         */
        public function updateTimestamp($sessionId, $data)
        {
            $this->memcached->touch($this->prefix.$sessionId, time() + $this->ttl);

            return true;
        }

        /**
         * {@inheritdoc}
         */
        protected function doWrite($sessionId, $data)
        {
            return $this->memcached->set($this->prefix.$sessionId, $data, time() + $this->ttl);
        }

        /**
         * {@inheritdoc}
         */
        protected function doDestroy($sessionId)
        {
            $result = $this->memcached->delete($this->prefix.$sessionId);

            return $result || \Memcached::RES_NOTFOUND == $this->memcached->getResultCode();
        }

        /**
         * {@inheritdoc}
         */
        public function gc($maxlifetime)
        {
            // not required here because memcached will auto expire the records anyhow.
            return true;
        }

        /**
         * Return a Memcached instance.
         *
         * @return \Memcached
         */
        protected function getMemcached()
        {
            return $this->memcached;
        }
    }