# AbstractSessionHandler

abstract class AbstractSessionHandler implements SessionHandlerInterface, SessionUpdateTimestampHandlerInterface

This abstract session handler provides a generic implementation of the PHP 7.0 SessionUpdateTimestampHandlerInterface, enabling strict and lazy session handling.

## Methods

`public` | `` | `open($savePath, $sessionName)` | {@inheritdoc} |
`abstract protected` | `string` | `doRead(string $sessionId)` | No description |
`abstract protected` | `bool` | `doWrite(string $sessionId, string $data)` | No description |
`abstract protected` | `bool` | `doDestroy(string $sessionId)` | No description |
`public` | `` | `validateId($sessionId)` | {@inheritdoc} |
`public` | `` | `read($sessionId)` | {@inheritdoc} |
`public` | `` | `write($sessionId, $data)` | {@inheritdoc} |
`public` | `` | `destroy($sessionId)` | {@inheritdoc} |

## Details

at line 32

### `open()`

`public open($savePath, $sessionName)`

{@inheritdoc}

#### Parameters

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

at line 47

### `doRead()`

`abstract protected string doRead(string $sessionId)`

#### Parameters

`string` | `$sessionId` |

#### Return Value

`string` |

at line 55

### `doWrite()`

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

#### Parameters

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

#### Return Value

`bool` |

at line 62

### `doDestroy()`

`abstract protected bool doDestroy(string $sessionId)`

#### Parameters

`string` | `$sessionId` |

#### Return Value

`bool` |

at line 67

### `validateId()`

`public validateId($sessionId)`

{@inheritdoc}

#### Parameters

| `$sessionId` |

at line 78

### `read()`

`public read($sessionId)`

{@inheritdoc}

#### Parameters

| `$sessionId` |

at line 101

### `write()`

`public write($sessionId, $data)`

{@inheritdoc}

#### Parameters

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

at line 118

### `destroy()`

`public destroy($sessionId)`

{@inheritdoc}

#### Parameters

| `$sessionId` |

## 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;

    /**
     * This abstract session handler provides a generic implementation
     * of the PHP 7.0 SessionUpdateTimestampHandlerInterface,
     * enabling strict and lazy session handling.
     *
     * @author Nicolas Grekas <p@tchwork.com>
     */
    abstract class AbstractSessionHandler implements \SessionHandlerInterface, \SessionUpdateTimestampHandlerInterface
    {
        private $sessionName;
        private $prefetchId;
        private $prefetchData;
        private $newSessionId;
        private $igbinaryEmptyData;

        /**
         * {@inheritdoc}
         */
        public function open($savePath, $sessionName)
        {
            $this->sessionName = $sessionName;
            if (!headers_sent() && !ini_get('session.cache_limiter') && '0' !== ini_get('session.cache_limiter')) {
                header(sprintf('Cache-Control: max-age=%d, private, must-revalidate', 60 * (int) ini_get('session.cache_expire')));
            }

            return true;
        }

        /**
         * @param string $sessionId
         *
         * @return string
         */
        abstract protected function doRead($sessionId);

        /**
         * @param string $sessionId
         * @param string $data
         *
         * @return bool
         */
        abstract protected function doWrite($sessionId, $data);

        /**
         * @param string $sessionId
         *
         * @return bool
         */
        abstract protected function doDestroy($sessionId);

        /**
         * {@inheritdoc}
         */
        public function validateId($sessionId)
        {
            $this->prefetchData = $this->read($sessionId);
            $this->prefetchId = $sessionId;

            return '' !== $this->prefetchData;
        }

        /**
         * {@inheritdoc}
         */
        public function read($sessionId)
        {
            if (null !== $this->prefetchId) {
                $prefetchId = $this->prefetchId;
                $prefetchData = $this->prefetchData;
                $this->prefetchId = $this->prefetchData = null;

                if ($prefetchId === $sessionId || '' === $prefetchData) {
                    $this->newSessionId = '' === $prefetchData ? $sessionId : null;

                    return $prefetchData;
                }
            }

            $data = $this->doRead($sessionId);
            $this->newSessionId = '' === $data ? $sessionId : null;

            return $data;
        }

        /**
         * {@inheritdoc}
         */
        public function write($sessionId, $data)
        {
            if (null === $this->igbinaryEmptyData) {
                // see https://github.com/igbinary/igbinary/issues/146
                $this->igbinaryEmptyData = \function_exists('igbinary_serialize') ? igbinary_serialize(array()) : '';
            }
            if ('' === $data || $this->igbinaryEmptyData === $data) {
                return $this->destroy($sessionId);
            }
            $this->newSessionId = null;

            return $this->doWrite($sessionId, $data);
        }

        /**
         * {@inheritdoc}
         */
        public function destroy($sessionId)
        {
            if (!headers_sent() && ini_get('session.use_cookies')) {
                if (!$this->sessionName) {
                    throw new \LogicException(sprintf('Session name cannot be empty, did you forget to call "parent::open()" in "%s"?.', get_class($this)));
                }
                $sessionCookie = sprintf(' %s=', urlencode($this->sessionName));
                $sessionCookieWithId = sprintf('%s%s;', $sessionCookie, urlencode($sessionId));
                $sessionCookieFound = false;
                $otherCookies = array();
                foreach (headers_list() as $h) {
                    if (0 !== stripos($h, 'Set-Cookie:')) {
                        continue;
                    }
                    if (11 === strpos($h, $sessionCookie, 11)) {
                        $sessionCookieFound = true;

                        if (11 !== strpos($h, $sessionCookieWithId, 11)) {
                            $otherCookies[] = $h;
                        }
                    } else {
                        $otherCookies[] = $h;
                    }
                }
                if ($sessionCookieFound) {
                    header_remove('Set-Cookie');
                    foreach ($otherCookies as $h) {
                        header($h, false);
                    }
                } else {
                    setcookie($this->sessionName, '', 0, ini_get('session.cookie_path'), ini_get('session.cookie_domain'), ini_get('session.cookie_secure'), ini_get('session.cookie_httponly'));
                }
            }

            return $this->newSessionId === $sessionId || $this->doDestroy($sessionId);
        }
    }