<?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		EllisLab Dev Team
 * @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 Redis Caching Class
 *
 * @package	   CodeIgniter
 * @subpackage Libraries
 * @category   Core
 * @author	   Anton Lindqvist <anton@qvister.se>
 * @link
 */
class CI_Cache_redis extends CI_Driver
{
	/**
	 * The name of the Redis set that is to store keys of serialized values.
	 */
	const KEY_SET_FOR_SERIALIZATION = '_ci_redis_serialization_set';

	/**
	 * Default config
	 *
	 * @static
	 * @var	array
	 */
	protected static $_default_config = array(
		'socket_type' => 'tcp',
		'host' => '127.0.0.1',
		'password' => NULL,
		'port' => 6379,
		'timeout' => 0
	);

	/**
	 * Redis connection
	 *
	 * @var	Redis
	 */
	protected $_redis;

	/**
	 * An internal cache for storing keys of serialized values.
	 *
	 * @var	array
	 */
	protected $_serialized;

	// ------------------------------------------------------------------------

	/**
	 * Get cache
	 *
	 * @param	string	Cache ID
	 * @return	mixed
	 */
	public function get($key)
	{
		$value = $this->_redis->get($key);

		if ($value !== FALSE && in_array($key, $this->_serialized, TRUE))
		{
			return unserialize($value);
		}

		return $value;
	}

	// ------------------------------------------------------------------------

	/**
	 * Save cache
	 *
	 * @param	string	$id	Cache ID
	 * @param	mixed	$data	Data to save
	 * @param	int	$ttl	Time to live in seconds
	 * @param	bool	$raw	Whether to store the raw value (unused)
	 * @return	bool	TRUE on success, FALSE on failure
	 */
	public function save($id, $data, $ttl = 60, $raw = FALSE)
	{
		if (is_array($data) OR is_object($data))
		{
			$data = serialize($data);

			if (($index_key = array_search($id, $this->_serialized, TRUE)) === FALSE)
			{
				$this->_serialized[] = $id;
			}

			$this->_redis->sAdd(self::KEY_SET_FOR_SERIALIZATION, $id);
		}
		else
		{
			if (($index_key = array_search($id, $this->_serialized, TRUE)) !== FALSE)
			{
				unset($this->_serialized[$index_key]);
			}

			$this->_redis->sRemove(self::KEY_SET_FOR_SERIALIZATION, $id);
		}

		return ($ttl)
			? $this->_redis->setex($id, $ttl, $data)
			: $this->_redis->set($id, $data);
	}

	// ------------------------------------------------------------------------

	/**
	 * Delete from cache
	 *
	 * @param	string	Cache key
	 * @return	bool
	 */
	public function delete($key)
	{
		if (($index_key = array_search($key, $this->_serialized, TRUE)) !== FALSE)
		{
			unset($this->_serialized[$index_key]);
		}

		$this->_redis->sRemove(self::KEY_SET_FOR_SERIALIZATION, $key);

		return ($this->_redis->delete($key) === 1);
	}

	// ------------------------------------------------------------------------

	/**
	 * Increment a raw value
	 *
	 * @param	string	$id	Cache ID
	 * @param	int	$offset	Step/value to add
	 * @return	mixed	New value on success or FALSE on failure
	 */
	public function increment($id, $offset = 1)
	{
		return $this->_redis->incr($id, $offset);
	}

	// ------------------------------------------------------------------------

	/**
	 * Decrement a raw value
	 *
	 * @param	string	$id	Cache ID
	 * @param	int	$offset	Step/value to reduce by
	 * @return	mixed	New value on success or FALSE on failure
	 */
	public function decrement($id, $offset = 1)
	{
		return $this->_redis->decr($id, $offset);
	}

	// ------------------------------------------------------------------------

	/**
	 * Clean cache
	 *
	 * @return	bool
	 * @see		Redis::flushDB()
	 */
	public function clean()
	{
		return $this->_redis->flushDB();
	}

	// ------------------------------------------------------------------------

	/**
	 * Get cache driver info
	 *
	 * @param	string	Not supported in Redis.
	 *			Only included in order to offer a
	 *			consistent cache API.
	 * @return	array
	 * @see		Redis::info()
	 */
	public function cache_info($type = NULL)
	{
		return $this->_redis->info();
	}

	// ------------------------------------------------------------------------

	/**
	 * Get cache metadata
	 *
	 * @param	string	Cache key
	 * @return	array
	 */
	public function get_metadata($key)
	{
		$value = $this->get($key);

		if ($value)
		{
			return array(
				'expire' => time() + $this->_redis->ttl($key),
				'data' => $value
			);
		}

		return FALSE;
	}

	// ------------------------------------------------------------------------

	/**
	 * Check if Redis driver is supported
	 *
	 * @return	bool
	 */
	public function is_supported()
	{
		if (extension_loaded('redis'))
		{
			return $this->_setup_redis();
		}
		else
		{
			log_message('debug', 'The Redis extension must be loaded to use Redis cache.');
			return FALSE;
		}
	}

	// ------------------------------------------------------------------------

	/**
	 * Setup Redis config and connection
	 *
	 * Loads Redis config file if present. Will halt execution
	 * if a Redis connection can't be established.
	 *
	 * @return	bool
	 * @see		Redis::connect()
	 */
	protected function _setup_redis()
	{
		$config = array();
		$CI =& get_instance();

		if ($CI->config->load('redis', TRUE, TRUE))
		{
			$config += $CI->config->item('redis');
		}

		$config = array_merge(self::$_default_config, $config);

		$this->_redis = new Redis();

		try
		{
			if ($config['socket_type'] === 'unix')
			{
				$success = $this->_redis->connect($config['socket']);
			}
			else // tcp socket
			{
				$success = $this->_redis->connect($config['host'], $config['port'], $config['timeout']);
			}

			if ( ! $success)
			{
				log_message('debug', 'Cache: Redis connection refused. Check the config.');
				return FALSE;
			}
		}
		catch (RedisException $e)
		{
			log_message('debug', 'Cache: Redis connection refused ('.$e->getMessage().')');
			return FALSE;
		}

		if (isset($config['password']))
		{
			$this->_redis->auth($config['password']);
		}

		// Initialize the index of selialized values.
		$this->_serialized = $this->_redis->sMembers(self::KEY_SET_FOR_SERIALIZATION);

		if (empty($this->_serialized))
		{
			// On error FALSE is returned, ensure array type for empty index.
			$this->_serialized = array();
		}

		return TRUE;
	}

	// ------------------------------------------------------------------------

	/**
	 * Class destructor
	 *
	 * Closes the connection to Redis if present.
	 *
	 * @return	void
	 */
	public function __destruct()
	{
		if ($this->_redis)
		{
			$this->_redis->close();
		}
	}

}

/* End of file Cache_redis.php */
/* Location: ./system/libraries/Cache/drivers/Cache_redis.php */