commitall

system/database/DB_cache.php

@@ -0,0 +1,221 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014 - 2019, 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 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
+ * @license	https://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);
+	}
+
+}