feature/session (#3073): Add Redis session driver
Seems like I forgot to 'git add' it in previous commit.
diff --git a/system/libraries/Session/drivers/Session_redis_driver.php b/system/libraries/Session/drivers/Session_redis_driver.php
new file mode 100644
index 0000000..6c013a6
--- /dev/null
+++ b/system/libraries/Session/drivers/Session_redis_driver.php
@@ -0,0 +1,311 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.2.4 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst. It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package CodeIgniter
+ * @author Andrey Andreev
+ * @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
+ * @license http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link http://codeigniter.com
+ * @since Version 3.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * CodeIgniter Session Redis Driver
+ *
+ * @package CodeIgniter
+ * @subpackage Libraries
+ * @category Sessions
+ * @author Andrey Andreev
+ * @link http://codeigniter.com/user_guide/libraries/sessions.html
+ */
+class CI_Session_redis_driver extends CI_Session_driver implements SessionHandlerInterface {
+
+ /**
+ * Save path
+ *
+ * @var string
+ */
+ protected $_save_path;
+
+ /**
+ * phpRedis instance
+ *
+ * @var resource
+ */
+ protected $_redis;
+
+ /**
+ * Key prefix
+ *
+ * @var string
+ */
+ protected $_key_prefix = 'ci_session:';
+
+ /**
+ * Lock key
+ *
+ * @var string
+ */
+ protected $_lock_key;
+
+ // ------------------------------------------------------------------------
+
+ /**
+ * Class constructor
+ *
+ * @param array $params Configuration parameters
+ * @return void
+ */
+ public function __construct(&$params)
+ {
+ parent::__construct($params);
+
+ if (empty($this->_save_path))
+ {
+ log_message('error', 'Session: No Redis save path configured.');
+ }
+ elseif (preg_match('#(?:tcp://)?([^:]+)(?:\:(\d+))?(\?.+)?#', $this->_save_path, $matches))
+ {
+ $this->_save_path = array(
+ 'host' => $matches[1],
+ 'port' => empty($matches[2]) ? NULL : $matches[2],
+ 'password' => preg_match('#auth=([^\s&]+)#', $matches[3], $match) ? $match[1] : NULL,
+ 'database' => preg_match('#database=(\d+)#', $matches[3], $match) ? (int) $match[1] : NULL,
+ 'timeout' => preg_match('#timeout=(\d+\.\d+)#', $matches[3], $match) ? (float) $match[1] : NULL
+ );
+
+ preg_match('#prefix=([^\s&]+)#', $matches[3], $match) && $this->_key_prefix = $match[1];
+ }
+ else
+ {
+ log_message('error', 'Session: Invalid Redis save path format: '.$this->_save_path);
+ }
+
+ if ($this->_match_ip === TRUE)
+ {
+ $this->_key_prefix .= $_SERVER['REMOTE_ADDR'].':';
+ }
+ }
+
+ // ------------------------------------------------------------------------
+
+ public function open($save_path, $name)
+ {
+ if (empty($this->_save_path))
+ {
+ return FALSE;
+ }
+
+ $redis = new Redis();
+ if ( ! $redis->connect($this->_save_path['host'], $this->_save_path['port'], $this->_save_path['timeout']))
+ {
+ log_message('error', 'Session: Unable to connect to Redis with the configured settings.');
+ }
+ elseif (isset($this->_save_path['password']) && ! $redis->auth($this->_save_path['password']))
+ {
+ log_message('error', 'Session: Unable to authenticate to Redis instance.');
+ }
+ elseif (isset($this->_save_path['database']) && ! $redis->select($this->_save_path['database']))
+ {
+ log_message('error', 'Session: Unable to select Redis database with index '.$this->_save_path['database']);
+ }
+ else
+ {
+ $this->_redis = $redis;
+ return TRUE;
+ }
+
+ return FALSE;
+ }
+
+ // ------------------------------------------------------------------------
+
+ public function read($session_id)
+ {
+ if (isset($this->_redis) && $this->_get_lock($session_id))
+ {
+ $session_data = (string) $this->_redis->get($this->_key_prefix.$session_id);
+ $this->_fingerprint = md5($session_data);
+ return $session_data;
+ }
+
+ return FALSE;
+ }
+
+ public function write($session_id, $session_data)
+ {
+ if (isset($this->_redis, $this->_lock_key))
+ {
+ $this->_redis->setTimeout($this->_lock_key, 10, time());
+ if ($this->_fingerprint !== ($fingerprint = md5($session_data)))
+ {
+ if ($this->_redis->set($this->_key_prefix.$session_id, $session_data, $this->_expiration))
+ {
+ $this->_fingerprint = $fingerprint;
+ return TRUE;
+ }
+
+ return FALSE;
+ }
+
+ return $this->_redis->setTimeout($this->_key_prefix.$session_id, $this->_expiration);
+ }
+
+ return FALSE;
+ }
+
+ // ------------------------------------------------------------------------
+
+ public function close()
+ {
+ if (isset($this->_redis))
+ {
+ try {
+ if ($this->_redis->ping() === '+PONG')
+ {
+ isset($this->_lock_key) && $this->_redis->delete($this->_lock_key);
+ if ( ! $this->_redis->close())
+ {
+ return FALSE;
+ }
+ }
+ }
+ catch (RedisException $e)
+ {
+ log_message('error', 'Session: Got RedisException on close(): '.$e->getMessage());
+ }
+
+ $this->_redis = NULL;
+ return TRUE;
+ }
+
+ return FALSE;
+ }
+
+ // ------------------------------------------------------------------------
+
+ public function destroy($session_id)
+ {
+ if (isset($this->_redis, $this->_lock_key))
+ {
+ if ($this->_redis->delete($this->_key_prefix.$session_id) !== 1)
+ {
+ log_message('debug', 'Session: Redis::delete() expected to return 1, got '.var_export($result, TRUE).' instead.');
+ }
+
+ return ($this->_cookie_destroy() && $this->close());
+ }
+
+ return $this->close();
+ }
+
+ // ------------------------------------------------------------------------
+
+ public function gc($maxlifetime)
+ {
+ // TODO: keys()/getKeys() is said to be performance-intensive,
+ // although it supports patterns (*, [charlist] at the very least).
+ // scan() seems to be recommended, but requires redis 2.8
+ // Not sure if we need any of these though, as we set keys with expire times
+ return TRUE;
+ }
+
+ // ------------------------------------------------------------------------
+
+ protected function _get_lock($session_id)
+ {
+ if (isset($this->_lock_key))
+ {
+ return $this->_redis->setTimeout($this->_lock_key, 5);
+ }
+
+ $lock_key = $this->_key_prefix.$session_id.':lock';
+ if (($ttl = $this->_redis->ttl($lock_key)) < 1)
+ {
+ if ( ! $this->_redis->setex($lock_key, 5, time()))
+ {
+ log_message('error', 'Session: Error while trying to obtain lock for '.$this->_key_prefix.$session_id);
+ return FALSE;
+ }
+
+ $this->_lock_key = $lock_key;
+
+ if ($ttl === -1)
+ {
+ log_message('debug', 'Session: Lock for '.$this->_key_prefix.$session_id.' had no TTL, overriding.');
+ }
+
+ $this->_lock = TRUE;
+ return TRUE;
+ }
+
+ // Another process has the lock, we'll try to wait for it to free itself ...
+ $attempt = 0;
+ while ($attempt++ < 5)
+ {
+ usleep(($ttl * 1000000) - 20000);
+ if (($ttl = $this->_redis->ttl($lock_key)) > 0)
+ {
+ continue;
+ }
+
+ if ( ! $this->_redis->setex($lock_key, 5, time()))
+ {
+ log_message('error', 'Session: Error while trying to obtain lock for '.$this->_key_prefix.$session_id);
+ return FALSE;
+ }
+
+ $this->_lock_key = $lock_key;
+ break;
+ }
+
+ if ($attempt === 5)
+ {
+ log_message('error', 'Session: Unable to obtain lock for '.$this->_key_prefix.$session_id.' after 5 attempts, aborting.');
+ return FALSE;
+ }
+
+ $this->_lock = TRUE;
+ return TRUE;
+ }
+
+ // ------------------------------------------------------------------------
+
+ protected function _release_lock()
+ {
+ if (isset($this->_redis, $this->_lock_key) && $this->_lock)
+ {
+ if ( ! $this->_redis->delete($this->_lock_key))
+ {
+ log_message('error', 'Session: Error while trying to free lock for '.$this->_key_prefix.$session_id);
+ return FALSE;
+ }
+
+ $this->_lock_key = NULL;
+ $this->_lock = FALSE;
+ }
+
+ return TRUE;
+ }
+
+}
+
+/* End of file Session_redis_driver.php */
+/* Location: ./system/libraries/Session/drivers/Session_redis_driver.php */
\ No newline at end of file