1 files changed, 187 insertions, 0 deletions

diff --git a/system/database/DB_cache.php b/system/database/DB_cache.php
new file mode 100644
index 000000000..135be3ce9
--- /dev/null
+++ b/system/database/DB_cache.php
@@ -0,0 +1,187 @@
+<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * Code Igniter
+ *
+ * An open source application development framework for PHP 4.3.2 or newer
+ *
+ * @package		CodeIgniter
+ * @author		Rick Ellis
+ * @copyright	Copyright (c) 2006, pMachine, Inc.
+ * @license		http://www.codeignitor.com/user_guide/license.html 
+ * @link		http://www.codeigniter.com
+ * @since		Version 1.0
+ * @filesource
+ */
+
+// ------------------------------------------------------------------------
+
+/**
+ * Database Cache Class
+ *
+ * @category	Database
+ * @author		Rick Ellis
+ * @link		http://www.codeigniter.com/user_guide/database/
+ */
+class CI_DB_Cache {
+
+	var $obj;
+
+	/**
+	 * Constructor
+	 *
+	 * Grabs the CI super object instance so we can access it.
+	 *
+	 */	
+	function CI_DB_Cache()
+	{
+		// Assign the main CI object to $this->obj
+		// and load the file helper since we use it a lot
+		$this->obj =& get_instance();
+		$this->obj->load->helper('file');	
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set Cache Directory Path
+	 *
+	 * @access	public
+	 * @param	string	the path to the cache directory
+	 * @return	bool
+	 */		
+	function check_path($path = '')
+	{
+		if ($path == '')
+		{
+			if ($this->obj->db->cachedir == '')
+			{
+				return $this->obj->db->cache_off();
+			}
+		
+			$path = $this->obj->db->cachedir;
+		}
+	
+		// Add a trailing slash to the path if needed
+		$path = preg_replace("/(.+?)\/*$/", "\\1/",  $path);
+	
+		if ( ! is_dir($path) OR ! is_writable($path))
+		{
+			if ($this->obj->db->db_debug)
+			{
+				return $this->obj->db->display_error('db_invalid_cache_path');
+			}
+			
+			// If the path is wrong we'll turn off caching
+			return $this->obj->db->cache_off();
+		}
+		
+		$this->obj->db->cachedir = $path;
+		return TRUE;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Retreive a cached query
+	 *
+	 * The URI being requested will become the name of the cache sub-folder.
+	 * An MD5 hash of the SQL statement will become the cache file name
+	 *
+	 * @access	public
+	 * @return	string
+	 */
+	function read($sql)
+	{
+		if ( ! $this->check_path())
+		{
+			return $this->obj->db->cache_off();
+		}
+	
+		$uri  = ($this->obj->uri->segment(1) == FALSE) ? 'base'  : $this->obj->uri->segment(2);
+		$uri .= ($this->obj->uri->segment(2) == FALSE) ? 'index' : $this->obj->uri->segment(2);
+		
+		$filepath = md5($uri).'/'.md5($sql);
+		
+		if (FALSE === ($cachedata = read_file($this->obj->db->cachedir.$filepath)))
+		{	
+			return FALSE;
+		}
+		
+		return unserialize($cachedata);			
+	}	
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Write a query to a cache file
+	 *
+	 * @access	public
+	 * @return	bool
+	 */
+	function write($sql, $object)
+	{
+		if ( ! $this->check_path())
+		{
+			return $this->obj->db->cache_off();
+		}
+
+		$uri  = ($this->obj->uri->segment(1) == FALSE) ? 'base'  : $this->obj->uri->segment(2);
+		$uri .= ($this->obj->uri->segment(2) == FALSE) ? 'index' : $this->obj->uri->segment(2);
+		
+		$dir_path = $this->obj->db->cachedir.md5($uri).'/';
+		
+		$filename = md5($sql);
+	
+		if ( ! @is_dir($dir_path))
+		{
+			if ( ! @mkdir($dir_path, 0777))
+			{
+				return FALSE;
+			}
+			
+			@chmod($dir_path, 0777);			
+		}
+		
+		if (write_file($dir_path.$filename, serialize($object)) === FALSE)
+		{
+			return FALSE;
+		}
+		
+		@chmod($dir_path.$filename, 0777);
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Delete cache files within a particular directory
+	 *
+	 * @access	public
+	 * @return	bool
+	 */
+	function delete()
+	{
+		$uri  = ($this->obj->uri->segment(1) == FALSE) ? 'base'  : $this->obj->uri->segment(2);
+		$uri .= ($this->obj->uri->segment(2) == FALSE) ? 'index' : $this->obj->uri->segment(2);
+		
+		$dir_path = $this->obj->db->cachedir.md5($uri).'/';
+		
+		delete_files($dir_path, TRUE);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Delete all existing cache files
+	 *
+	 * @access	public
+	 * @return	bool
+	 */
+	function delete_all()
+	{
+		delete_files($this->obj->db->cachedir, TRUE);
+	}
+
+}
+
+?>
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