Subversion-Projekte lars-tiefland.ci

<?php

/**

 * CodeIgniter

 *

 * An open source application development framework for PHP

 *

 * This content is released under the MIT License (MIT)

 *

 * Copyright (c) 2014 - 2017, British Columbia Institute of Technology

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 *

 * @package	CodeIgniter

 * @author	EllisLab Dev Team

 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)

 * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)

 * @license	http://opensource.org/licenses/MIT	MIT License

 * @link	https://codeigniter.com

 * @since	Version 1.0.0

 * @filesource

 */

defined('BASEPATH') OR exit('No direct script access allowed');

/**

 * Database Cache Class

 *

 * @category	Database

 * @author		EllisLab Dev Team

 * @link		https://codeigniter.com/user_guide/database/

 */

class CI_DB_Cache {

	/**

	 * CI Singleton

	 *

	 * @var	object

	 */

	public $CI;

	/**

	 * Database object

	 *

	 * Allows passing of DB object so that multiple database connections

	 * and returned DB objects can be supported.

	 *

	 * @var	object

	 */

	public $db;

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

	/**

	 * Constructor

	 *

	 * @param	object	&$db

	 * @return	void

	 */

	public function __construct(&$db)

	{

		// Assign the main CI object to $this->CI and load the file helper since we use it a lot

		$this->CI =& get_instance();

		$this->db =& $db;

		$this->CI->load->helper('file');

		$this->check_path();

	}

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

	/**

	 * Set Cache Directory Path

	 *

	 * @param	string	$path	Path to the cache directory

	 * @return	bool

	 */

	public function check_path($path = '')

	{

		if ($path === '')

		{

			if ($this->db->cachedir === '')

			{

				return $this->db->cache_off();

			}

			$path = $this->db->cachedir;

		}

		// Add a trailing slash to the path if needed

		$path = realpath($path)

			? rtrim(realpath($path), DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR

			: rtrim($path, '/').'/';

		if ( ! is_dir($path))

		{

			log_message('debug', 'DB cache path error: '.$path);

			// If the path is wrong we'll turn off caching

			return $this->db->cache_off();

		}

		if ( ! is_really_writable($path))

		{

			log_message('debug', 'DB cache dir not writable: '.$path);

			// If the path is not really writable we'll turn off caching

			return $this->db->cache_off();

		}

		$this->db->cachedir = $path;

		return TRUE;

	}

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

	/**

	 * Retrieve a cached query

	 *

	 * The URI being requested will become the name of the cache sub-folder.

	 * An MD5 hash of the SQL statement will become the cache file name.

	 *

	 * @param	string	$sql

	 * @return	string

	 */

	public function read($sql)

	{

		$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);

		$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);

		$filepath = $this->db->cachedir.$segment_one.'+'.$segment_two.'/'.md5($sql);

		if ( ! is_file($filepath) OR FALSE === ($cachedata = file_get_contents($filepath)))

		{

			return FALSE;

		}

		return unserialize($cachedata);

	}

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

	/**

	 * Write a query to a cache file

	 *

	 * @param	string	$sql

	 * @param	object	$object

	 * @return	bool

	 */

	public function write($sql, $object)

	{

		$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);

		$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);

		$dir_path = $this->db->cachedir.$segment_one.'+'.$segment_two.'/';

		$filename = md5($sql);

		if ( ! is_dir($dir_path) && ! @mkdir($dir_path, 0750))

		{

			return FALSE;

		}

		if (write_file($dir_path.$filename, serialize($object)) === FALSE)

		{

			return FALSE;

		}

		chmod($dir_path.$filename, 0640);

		return TRUE;

	}

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

	/**

	 * Delete cache files within a particular directory

	 *

	 * @param	string	$segment_one

	 * @param	string	$segment_two

	 * @return	void

	 */

	public function delete($segment_one = '', $segment_two = '')

	{

		if ($segment_one === '')

		{

			$segment_one  = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);

		}

		if ($segment_two === '')

		{

			$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);

		}

		$dir_path = $this->db->cachedir.$segment_one.'+'.$segment_two.'/';

		delete_files($dir_path, TRUE);

	}

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

	/**

	 * Delete all existing cache files

	 *

	 * @return	void

	 */

	public function delete_all()

	{

		delete_files($this->db->cachedir, TRUE, TRUE);

	}

}