# RedisSessionHandler

class RedisSessionHandler extends AbstractSessionHandler

Redis based session storage handler based on the Redis class provided by the PHP redis 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(Redis|RedisArray|RedisCluster|Client $redis, array $options = array())` | List of available options: * prefix: The prefix to use for the keys in order to avoid collision on the Redis server. |
`public` | `bool` | `close()` | {@inheritdoc} |
`public` | `bool` | `gc($maxlifetime)` | {@inheritdoc} |
`public` | `` | `updateTimestamp($sessionId, $data)` | {@inheritdoc} |

## Details

in AbstractSessionHandler at line 32

### `open()`

`public open($savePath, $sessionName)`

{@inheritdoc}

#### Parameters

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

at line 57

### `doRead()`

`protected string doRead(string $sessionId)`

#### Parameters

`string` | `$sessionId` |

#### Return Value

`string` |

at line 65

### `doWrite()`

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

#### Parameters

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

#### Return Value

`bool` |

at line 75

### `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 40

### `__construct()`

`public __construct(Redis|RedisArray|RedisCluster|Client $redis, array $options = array())`

List of available options: * prefix: The prefix to use for the keys in order to avoid collision on the Redis server.

#### Parameters

`Redis|RedisArray|RedisCluster|Client` | `$redis` |
`array` | `$options` | An associative array of options

#### Exceptions

InvalidArgumentException | When unsupported client or options are passed

at line 85

### `close()`

`public bool close()`

{@inheritdoc}

#### Return Value

`bool` |

at line 93

### `gc()`

`public bool gc($maxlifetime)`

{@inheritdoc}

#### Parameters

| `$maxlifetime` |

#### Return Value

`bool` |

at line 101

### `updateTimestamp()`

`public updateTimestamp($sessionId, $data)`

{@inheritdoc}

#### Parameters

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

## 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;

    use Predis\Response\ErrorInterface;

    /**
     * Redis based session storage handler based on the Redis class
     * provided by the PHP redis extension.
     *
     * @author Dalibor Karlović <dalibor@flexolabs.io>
     */
    class RedisSessionHandler extends AbstractSessionHandler
    {
        private $redis;

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

        /**
         * List of available options:
         *  * prefix: The prefix to use for the keys in order to avoid collision on the Redis server.
         *
         * @param \Redis|\RedisArray|\RedisCluster|\Predis\Client $redis
         * @param array                                           $options An associative array of options
         *
         * @throws \InvalidArgumentException When unsupported client or options are passed
         */
        public function __construct($redis, array $options = array())
        {
            if (!$redis instanceof \Redis && !$redis instanceof \RedisArray && !$redis instanceof \Predis\Client && !$redis instanceof RedisProxy) {
                throw new \InvalidArgumentException(sprintf('%s() expects parameter 1 to be Redis, RedisArray, RedisCluster or Predis\Client, %s given', __METHOD__, is_object($redis) ? get_class($redis) : gettype($redis)));
            }

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

            $this->redis = $redis;
            $this->prefix = $options['prefix'] ?? 'sf_s';
        }

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

        /**
         * {@inheritdoc}
         */
        protected function doWrite($sessionId, $data): bool
        {
            $result = $this->redis->setEx($this->prefix.$sessionId, (int) ini_get('session.gc_maxlifetime'), $data);

            return $result && !$result instanceof ErrorInterface;
        }

        /**
         * {@inheritdoc}
         */
        protected function doDestroy($sessionId): bool
        {
            $this->redis->del($this->prefix.$sessionId);

            return true;
        }

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

        /**
         * {@inheritdoc}
         */
        public function gc($maxlifetime): bool
        {
            return true;
        }

        /**
         * {@inheritdoc}
         */
        public function updateTimestamp($sessionId, $data)
        {
            return $this->redis->expire($this->prefix.$sessionId, (int) ini_get('session.gc_maxlifetime'));
        }
    }