Rename 'kohana' to 'system' to conform to the Kohana filesystem layout. I'm comfortable with us not clearly drawing the distinction about the fact that it's Kohana.

6 files changed, 958 insertions, 0 deletions

diff --git a/system/libraries/drivers/Cache/Apc.php b/system/libraries/drivers/Cache/Apc.php
new file mode 100644
index 00000000..f7be048f
--- /dev/null
+++ b/system/libraries/drivers/Cache/Apc.php
@@ -0,0 +1,64 @@
+<?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * APC-based Cache driver.
+ *
+ * $Id: Apc.php 4046 2009-03-05 19:23:29Z Shadowhand $
+ *
+ * @package    Cache
+ * @author     Kohana Team
+ * @copyright  (c) 2007-2008 Kohana Team
+ * @license    http://kohanaphp.com/license.html
+ */
+class Cache_Apc_Driver implements Cache_Driver {
+
+	public function __construct()
+	{
+		if ( ! extension_loaded('apc'))
+			throw new Kohana_Exception('cache.extension_not_loaded', 'apc');
+	}
+
+	public function get($id)
+	{
+		return (($return = apc_fetch($id)) === FALSE) ? NULL : $return;
+	}
+
+	public function set($id, $data, array $tags = NULL, $lifetime)
+	{
+		if ( ! empty($tags))
+		{
+			Kohana::log('error', 'Cache: tags are unsupported by the APC driver');
+		}
+
+		return apc_store($id, $data, $lifetime);
+	}
+
+	public function find($tag)
+	{
+		Kohana::log('error', 'Cache: tags are unsupported by the APC driver');
+
+		return array();
+	}
+
+	public function delete($id, $tag = FALSE)
+	{
+		if ($tag === TRUE)
+		{
+			Kohana::log('error', 'Cache: tags are unsupported by the APC driver');
+			return FALSE;
+		}
+		elseif ($id === TRUE)
+		{
+			return apc_clear_cache('user');
+		}
+		else
+		{
+			return apc_delete($id);
+		}
+	}
+
+	public function delete_expired()
+	{
+		return TRUE;
+	}
+
+} // End Cache APC Driver
\ No newline at end of file
diff --git a/system/libraries/drivers/Cache/Eaccelerator.php b/system/libraries/drivers/Cache/Eaccelerator.php
new file mode 100644
index 00000000..a45616d5
--- /dev/null
+++ b/system/libraries/drivers/Cache/Eaccelerator.php
@@ -0,0 +1,66 @@
+<?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * Eaccelerator-based Cache driver.
+ *
+ * $Id: Eaccelerator.php 4046 2009-03-05 19:23:29Z Shadowhand $
+ *
+ * @package    Cache
+ * @author     Kohana Team
+ * @copyright  (c) 2007-2008 Kohana Team
+ * @license    http://kohanaphp.com/license.html
+ */
+class Cache_Eaccelerator_Driver implements Cache_Driver {
+
+	public function __construct()
+	{
+		if ( ! extension_loaded('eaccelerator'))
+			throw new Kohana_Exception('cache.extension_not_loaded', 'eaccelerator');
+	}
+
+	public function get($id)
+	{
+		return eaccelerator_get($id);
+	}
+
+	public function find($tag)
+	{
+		Kohana::log('error', 'tags are unsupported by the eAccelerator driver');
+
+		return array();
+	}
+
+	public function set($id, $data, array $tags = NULL, $lifetime)
+	{
+		if ( ! empty($tags))
+		{
+			Kohana::log('error', 'tags are unsupported by the eAccelerator driver');
+		}
+
+		return eaccelerator_put($id, $data, $lifetime);
+	}
+
+	public function delete($id, $tag = FALSE)
+	{
+		if ($tag === TRUE)
+		{
+			Kohana::log('error', 'tags are unsupported by the eAccelerator driver');
+			return FALSE;
+		}
+		elseif ($id === TRUE)
+		{
+			return eaccelerator_clean();
+		}
+		else
+		{
+			return eaccelerator_rm($id);
+		}
+	}
+
+	public function delete_expired()
+	{
+		eaccelerator_gc();
+
+		return TRUE;
+	}
+
+} // End Cache eAccelerator Driver
\ No newline at end of file
diff --git a/system/libraries/drivers/Cache/File.php b/system/libraries/drivers/Cache/File.php
new file mode 100644
index 00000000..cc9d48d3
--- /dev/null
+++ b/system/libraries/drivers/Cache/File.php
@@ -0,0 +1,261 @@
+<?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * File-based Cache driver.
+ *
+ * $Id: File.php 4046 2009-03-05 19:23:29Z Shadowhand $
+ *
+ * @package    Cache
+ * @author     Kohana Team
+ * @copyright  (c) 2007-2008 Kohana Team
+ * @license    http://kohanaphp.com/license.html
+ */
+class Cache_File_Driver implements Cache_Driver {
+
+	protected $directory = '';
+
+	/**
+	 * Tests that the storage location is a directory and is writable.
+	 */
+	public function __construct($directory)
+	{
+		// Find the real path to the directory
+		$directory = str_replace('\\', '/', realpath($directory)).'/';
+
+		// Make sure the cache directory is writable
+		if ( ! is_dir($directory) OR ! is_writable($directory))
+			throw new Kohana_Exception('cache.unwritable', $directory);
+
+		// Directory is valid
+		$this->directory = $directory;
+	}
+
+	/**
+	 * Finds an array of files matching the given id or tag.
+	 *
+	 * @param  string  cache id or tag
+	 * @param  bool    search for tags
+	 * @return array   of filenames matching the id or tag
+	 */
+	public function exists($id, $tag = FALSE)
+	{
+		if ($id === TRUE)
+		{
+			// Find all the files
+			return glob($this->directory.'*~*~*');
+		}
+		elseif ($tag === TRUE)
+		{
+			// Find all the files that have the tag name
+			$paths = glob($this->directory.'*~*'.$id.'*~*');
+
+			// Find all tags matching the given tag
+			$files = array();
+			foreach ($paths as $path)
+			{
+				// Split the files
+				$tags = explode('~', basename($path));
+
+				// Find valid tags
+				if (count($tags) !== 3 OR empty($tags[1]))
+					continue;
+
+				// Split the tags by plus signs, used to separate tags
+				$tags = explode('+', $tags[1]);
+
+				if (in_array($tag, $tags))
+				{
+					// Add the file to the array, it has the requested tag
+					$files[] = $path;
+				}
+			}
+
+			return $files;
+		}
+		else
+		{
+			// Find the file matching the given id
+			return glob($this->directory.$id.'~*');
+		}
+	}
+
+	/**
+	 * Sets a cache item to the given data, tags, and lifetime.
+	 *
+	 * @param   string   cache id to set
+	 * @param   string   data in the cache
+	 * @param   array    cache tags
+	 * @param   integer  lifetime
+	 * @return  bool
+	 */
+	public function set($id, $data, array $tags = NULL, $lifetime)
+	{
+		// Remove old cache files
+		$this->delete($id);
+
+		// Cache File driver expects unix timestamp
+		if ($lifetime !== 0)
+		{
+			$lifetime += time();
+		}
+
+		if ( ! empty($tags))
+		{
+			// Convert the tags into a string list
+			$tags = implode('+', $tags);
+		}
+
+		// Write out a serialized cache
+		return (bool) file_put_contents($this->directory.$id.'~'.$tags.'~'.$lifetime, serialize($data));
+	}
+
+	/**
+	 * Finds an array of ids for a given tag.
+	 *
+	 * @param  string  tag name
+	 * @return array   of ids that match the tag
+	 */
+	public function find($tag)
+	{
+		// An array will always be returned
+		$result = array();
+
+		if ($paths = $this->exists($tag, TRUE))
+		{
+			// Length of directory name
+			$offset = strlen($this->directory);
+
+			// Find all the files with the given tag
+			foreach ($paths as $path)
+			{
+				// Get the id from the filename
+				list($id, $junk) = explode('~', basename($path), 2);
+
+				if (($data = $this->get($id)) !== FALSE)
+				{
+					// Add the result to the array
+					$result[$id] = $data;
+				}
+			}
+		}
+
+		return $result;
+	}
+
+	/**
+	 * Fetches a cache item. This will delete the item if it is expired or if
+	 * the hash does not match the stored hash.
+	 *
+	 * @param   string  cache id
+	 * @return  mixed|NULL
+	 */
+	public function get($id)
+	{
+		if ($file = $this->exists($id))
+		{
+			// Use the first file
+			$file = current($file);
+
+			// Validate that the cache has not expired
+			if ($this->expired($file))
+			{
+				// Remove this cache, it has expired
+				$this->delete($id);
+			}
+			else
+			{
+				// Turn off errors while reading the file
+				$ER = error_reporting(0);
+
+				if (($data = file_get_contents($file)) !== FALSE)
+				{
+					// Unserialize the data
+					$data = unserialize($data);
+				}
+				else
+				{
+					// Delete the data
+					unset($data);
+				}
+
+				// Turn errors back on
+				error_reporting($ER);
+			}
+		}
+
+		// Return NULL if there is no data
+		return isset($data) ? $data : NULL;
+	}
+
+	/**
+	 * Deletes a cache item by id or tag
+	 *
+	 * @param   string   cache id or tag, or TRUE for "all items"
+	 * @param   boolean  use tags
+	 * @return  boolean
+	 */
+	public function delete($id, $tag = FALSE)
+	{
+		$files = $this->exists($id, $tag);
+
+		if (empty($files))
+			return FALSE;
+
+		// Disable all error reporting while deleting
+		$ER = error_reporting(0);
+
+		foreach ($files as $file)
+		{
+			// Remove the cache file
+			if ( ! unlink($file))
+				Kohana::log('error', 'Cache: Unable to delete cache file: '.$file);
+		}
+
+		// Turn on error reporting again
+		error_reporting($ER);
+
+		return TRUE;
+	}
+
+	/**
+	 * Deletes all cache files that are older than the current time.
+	 *
+	 * @return void
+	 */
+	public function delete_expired()
+	{
+		if ($files = $this->exists(TRUE))
+		{
+			// Disable all error reporting while deleting
+			$ER = error_reporting(0);
+
+			foreach ($files as $file)
+			{
+				if ($this->expired($file))
+				{
+					// The cache file has already expired, delete it
+					if ( ! unlink($file))
+						Kohana::log('error', 'Cache: Unable to delete cache file: '.$file);
+				}
+			}
+
+			// Turn on error reporting again
+			error_reporting($ER);
+		}
+	}
+
+	/**
+	 * Check if a cache file has expired by filename.
+	 *
+	 * @param  string  filename
+	 * @return bool
+	 */
+	protected function expired($file)
+	{
+		// Get the expiration time
+		$expires = (int) substr($file, strrpos($file, '~') + 1);
+
+		// Expirations of 0 are "never expire"
+		return ($expires !== 0 AND $expires <= time());
+	}
+
+} // End Cache File Driver
\ No newline at end of file
diff --git a/system/libraries/drivers/Cache/Memcache.php b/system/libraries/drivers/Cache/Memcache.php
new file mode 100644
index 00000000..d801de9c
--- /dev/null
+++ b/system/libraries/drivers/Cache/Memcache.php
@@ -0,0 +1,191 @@
+<?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * Memcache-based Cache driver.
+ *
+ * $Id: Memcache.php 4102 2009-03-19 12:55:54Z Shadowhand $
+ *
+ * @package    Cache
+ * @author     Kohana Team
+ * @copyright  (c) 2007-2008 Kohana Team
+ * @license    http://kohanaphp.com/license.html
+ */
+class Cache_Memcache_Driver implements Cache_Driver {
+
+	const TAGS_KEY = 'memcache_tags_array';
+
+	// Cache backend object and flags
+	protected $backend;
+	protected $flags;
+
+	// Tags array
+	protected static $tags;
+
+	// Have the tags been changed?
+	protected static $tags_changed = FALSE;
+
+	public function __construct()
+	{
+		if ( ! extension_loaded('memcache'))
+			throw new Kohana_Exception('cache.extension_not_loaded', 'memcache');
+
+		$this->backend = new Memcache;
+		$this->flags = Kohana::config('cache_memcache.compression') ? MEMCACHE_COMPRESSED : FALSE;
+
+		$servers = Kohana::config('cache_memcache.servers');
+
+		foreach ($servers as $server)
+		{
+			// Make sure all required keys are set
+			$server += array('host' => '127.0.0.1', 'port' => 11211, 'persistent' => FALSE);
+
+			// Add the server to the pool
+			$this->backend->addServer($server['host'], $server['port'], (bool) $server['persistent'])
+				or Kohana::log('error', 'Cache: Connection failed: '.$server['host']);
+		}
+
+		// Load tags
+		self::$tags = $this->backend->get(self::TAGS_KEY);
+
+		if ( ! is_array(self::$tags))
+		{
+			// Create a new tags array
+			self::$tags = array();
+
+			// Tags have been created
+			self::$tags_changed = TRUE;
+		}
+	}
+
+	public function __destruct()
+	{
+		if (self::$tags_changed === TRUE)
+		{
+			// Save the tags
+			$this->backend->set(self::TAGS_KEY, self::$tags, $this->flags, 0);
+
+			// Tags are now unchanged
+			self::$tags_changed = FALSE;
+		}
+	}
+
+	public function find($tag)
+	{
+		if (isset(self::$tags[$tag]) AND $results = $this->backend->get(self::$tags[$tag]))
+		{
+				// Return all the found caches
+				return $results;
+		}
+		else
+		{
+			// No matching tags
+			return array();
+		}
+	}
+
+	public function get($id)
+	{
+		return (($return = $this->backend->get($id)) === FALSE) ? NULL : $return;
+	}
+
+	public function set($id, $data, array $tags = NULL, $lifetime)
+	{
+		if ( ! empty($tags))
+		{
+			// Tags will be changed
+			self::$tags_changed = TRUE;
+
+			foreach ($tags as $tag)
+			{
+				// Add the id to each tag
+				self::$tags[$tag][$id] = $id;
+			}
+		}
+
+		if ($lifetime !== 0)
+		{
+			// Memcache driver expects unix timestamp
+			$lifetime += time();
+		}
+
+		// Set a new value
+		return $this->backend->set($id, $data, $this->flags, $lifetime);
+	}
+
+	public function delete($id, $tag = FALSE)
+	{
+		// Tags will be changed
+		self::$tags_changed = TRUE;
+
+		if ($id === TRUE)
+		{
+			if ($status = $this->backend->flush())
+			{
+				// Remove all tags, all items have been deleted
+				self::$tags = array();
+
+				// We must sleep after flushing, or overwriting will not work!
+				// @see http://php.net/manual/en/function.memcache-flush.php#81420
+				sleep(1);
+			}
+
+			return $status;
+		}
+		elseif ($tag === TRUE)
+		{
+			if (isset(self::$tags[$id]))
+			{
+				foreach (self::$tags[$id] as $_id)
+				{
+					// Delete each id in the tag
+					$this->backend->delete($_id);
+				}
+
+				// Delete the tag
+				unset(self::$tags[$id]);
+			}
+
+			return TRUE;
+		}
+		else
+		{
+			foreach (self::$tags as $tag => $_ids)
+			{
+				if (isset(self::$tags[$tag][$id]))
+				{
+					// Remove the id from the tags
+					unset(self::$tags[$tag][$id]);
+				}
+			}
+
+			return $this->backend->delete($id);
+		}
+	}
+
+	public function delete_expired()
+	{
+		// Tags will be changed
+		self::$tags_changed = TRUE;
+
+		foreach (self::$tags as $tag => $_ids)
+		{
+			foreach ($_ids as $id)
+			{
+				if ( ! $this->backend->get($id))
+				{
+					// This id has disappeared, delete it from the tags
+					unset(self::$tags[$tag][$id]);
+				}
+			}
+
+			if (empty(self::$tags[$tag]))
+			{
+				// The tag no longer has any valid ids
+				unset(self::$tags[$tag]);
+			}
+		}
+
+		// Memcache handles garbage collection internally
+		return TRUE;
+	}
+
+} // End Cache Memcache Driver
diff --git a/system/libraries/drivers/Cache/Sqlite.php b/system/libraries/drivers/Cache/Sqlite.php
new file mode 100644
index 00000000..9458d851
--- /dev/null
+++ b/system/libraries/drivers/Cache/Sqlite.php
@@ -0,0 +1,257 @@
+<?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * SQLite-based Cache driver.
+ *
+ * $Id: Sqlite.php 4046 2009-03-05 19:23:29Z Shadowhand $
+ *
+ * @package    Cache
+ * @author     Kohana Team
+ * @copyright  (c) 2007-2008 Kohana Team
+ * @license    http://kohanaphp.com/license.html
+ */
+class Cache_Sqlite_Driver implements Cache_Driver {
+
+	// SQLite database instance
+	protected $db;
+
+	// Database error messages
+	protected $error;
+
+	/**
+	 * Logs an SQLite error.
+	 */
+	protected static function log_error($code)
+	{
+		// Log an error
+		Kohana::log('error', 'Cache: SQLite error: '.sqlite_error_string($error));
+	}
+
+	/**
+	 * Tests that the storage location is a directory and is writable.
+	 */
+	public function __construct($filename)
+	{
+		// Get the directory name
+		$directory = str_replace('\\', '/', realpath(pathinfo($filename, PATHINFO_DIRNAME))).'/';
+
+		// Set the filename from the real directory path
+		$filename = $directory.basename($filename);
+
+		// Make sure the cache directory is writable
+		if ( ! is_dir($directory) OR ! is_writable($directory))
+			throw new Kohana_Exception('cache.unwritable', $directory);
+
+		// Make sure the cache database is writable
+		if (is_file($filename) AND ! is_writable($filename))
+			throw new Kohana_Exception('cache.unwritable', $filename);
+
+		// Open up an instance of the database
+		$this->db = new SQLiteDatabase($filename, '0666', $error);
+
+		// Throw an exception if there's an error
+		if ( ! empty($error))
+			throw new Kohana_Exception('cache.driver_error', sqlite_error_string($error));
+
+		$query  = "SELECT name FROM sqlite_master WHERE type = 'table' AND name = 'caches'";
+		$tables = $this->db->query($query, SQLITE_BOTH, $error);
+
+		// Throw an exception if there's an error
+		if ( ! empty($error))
+			throw new Kohana_Exception('cache.driver_error', sqlite_error_string($error));
+
+		if ($tables->numRows() == 0)
+		{
+			Kohana::log('error', 'Cache: Initializing new SQLite cache database');
+
+			// Issue a CREATE TABLE command
+			$this->db->unbufferedQuery(Kohana::config('cache_sqlite.schema'));
+		}
+	}
+
+	/**
+	 * Checks if a cache id is already set.
+	 *
+	 * @param  string   cache id
+	 * @return boolean
+	 */
+	public function exists($id)
+	{
+		// Find the id that matches
+		$query = "SELECT id FROM caches WHERE id = '$id'";
+
+		return ($this->db->query($query)->numRows() > 0);
+	}
+
+	/**
+	 * Sets a cache item to the given data, tags, and lifetime.
+	 *
+	 * @param   string   cache id to set
+	 * @param   string   data in the cache
+	 * @param   array    cache tags
+	 * @param   integer  lifetime
+	 * @return  bool
+	 */
+	public function set($id, $data, array $tags = NULL, $lifetime)
+	{
+		// Serialize and escape the data
+		$data = sqlite_escape_string(serialize($data));
+
+		if ( ! empty($tags))
+		{
+			// Escape the tags, adding brackets so the tag can be explicitly matched
+			$tags = sqlite_escape_string('<'.implode('>,<', $tags).'>');
+		}
+
+		// Cache Sqlite driver expects unix timestamp
+		if ($lifetime !== 0)
+		{
+			$lifetime += time();
+		}
+
+		$query = $this->exists($id)
+			? "UPDATE caches SET tags = '$tags', expiration = '$lifetime', cache = '$data' WHERE id = '$id'"
+			: "INSERT INTO caches VALUES('$id', '$tags', '$lifetime', '$data')";
+
+		// Run the query
+		$this->db->unbufferedQuery($query, SQLITE_BOTH, $error);
+
+		if ( ! empty($error))
+		{
+			self::log_error($error);
+			return FALSE;
+		}
+		else
+		{
+			return TRUE;
+		}
+	}
+
+	/**
+	 * Finds an array of ids for a given tag.
+	 *
+	 * @param  string  tag name
+	 * @return array   of ids that match the tag
+	 */
+	public function find($tag)
+	{
+		$query = "SELECT id,cache FROM caches WHERE tags LIKE '%<{$tag}>%'";
+		$query = $this->db->query($query, SQLITE_BOTH, $error);
+
+		// An array will always be returned
+		$result = array();
+
+		if ( ! empty($error))
+		{
+			self::log_error($error);
+		}
+		elseif ($query->numRows() > 0)
+		{
+			// Disable notices for unserializing
+			$ER = error_reporting(~E_NOTICE);
+
+			while ($row = $query->fetchObject())
+			{
+				// Add each cache to the array
+				$result[$row->id] = unserialize($row->cache);
+			}
+
+			// Turn notices back on
+			error_reporting($ER);
+		}
+
+		return $result;
+	}
+
+	/**
+	 * Fetches a cache item. This will delete the item if it is expired or if
+	 * the hash does not match the stored hash.
+	 *
+	 * @param  string  cache id
+	 * @return mixed|NULL
+	 */
+	public function get($id)
+	{
+		$query = "SELECT id, expiration, cache FROM caches WHERE id = '$id' LIMIT 0, 1";
+		$query = $this->db->query($query, SQLITE_BOTH, $error);
+
+		if ( ! empty($error))
+		{
+			self::log_error($error);
+		}
+		elseif ($cache = $query->fetchObject())
+		{
+			// Make sure the expiration is valid and that the hash matches
+			if ($cache->expiration != 0 AND $cache->expiration <= time())
+			{
+				// Cache is not valid, delete it now
+				$this->delete($cache->id);
+			}
+			else
+			{
+				// Disable notices for unserializing
+				$ER = error_reporting(~E_NOTICE);
+				
+				// Return the valid cache data
+				$data = $cache->cache;
+
+				// Turn notices back on
+				error_reporting($ER);
+			}
+		}
+
+		// No valid cache found
+		return NULL;
+	}
+
+	/**
+	 * Deletes a cache item by id or tag
+	 *
+	 * @param  string  cache id or tag, or TRUE for "all items"
+	 * @param  bool    delete a tag
+	 * @return bool
+	 */
+	public function delete($id, $tag = FALSE)
+	{
+		if ($id === TRUE)
+		{
+			// Delete all caches
+			$where = '1';
+		}
+		elseif ($tag === TRUE)
+		{
+			// Delete by tag
+			$where = "tags LIKE '%<{$id}>%'";
+		}
+		else
+		{
+			// Delete by id
+			$where = "id = '$id'";
+		}
+
+		$this->db->unbufferedQuery('DELETE FROM caches WHERE '.$where, SQLITE_BOTH, $error);
+
+		if ( ! empty($error))
+		{
+			self::log_error($error);
+			return FALSE;
+		}
+		else
+		{
+			return TRUE;
+		}
+	}
+
+	/**
+	 * Deletes all cache files that are older than the current time.
+	 */
+	public function delete_expired()
+	{
+		// Delete all expired caches
+		$query = 'DELETE FROM caches WHERE expiration != 0 AND expiration <= '.time();
+
+		$this->db->unbufferedQuery($query);
+
+		return TRUE;
+	}
+
+} // End Cache SQLite Driver
\ No newline at end of file
diff --git a/system/libraries/drivers/Cache/Xcache.php b/system/libraries/drivers/Cache/Xcache.php
new file mode 100644
index 00000000..6254bbb6
--- /dev/null
+++ b/system/libraries/drivers/Cache/Xcache.php
@@ -0,0 +1,119 @@
+<?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * Xcache Cache driver.
+ *
+ * $Id: Xcache.php 4046 2009-03-05 19:23:29Z Shadowhand $
+ *
+ * @package    Cache
+ * @author     Kohana Team
+ * @copyright  (c) 2007-2008 Kohana Team
+ * @license    http://kohanaphp.com/license.html
+ */
+class Cache_Xcache_Driver implements Cache_Driver {
+
+	public function __construct()
+	{
+		if ( ! extension_loaded('xcache'))
+			throw new Kohana_Exception('cache.extension_not_loaded', 'xcache');
+	}
+
+	public function get($id)
+	{
+		if (xcache_isset($id))
+			return xcache_get($id);
+
+		return NULL;
+	}
+
+	public function set($id, $data, array $tags = NULL, $lifetime)
+	{
+		if ( ! empty($tags))
+		{
+			Kohana::log('error', 'Cache: tags are unsupported by the Xcache driver');
+		}
+
+		return xcache_set($id, $data, $lifetime);
+	}
+
+	public function find($tag)
+	{
+		Kohana::log('error', 'Cache: tags are unsupported by the Xcache driver');
+		return FALSE;
+	}
+
+	public function delete($id, $tag = FALSE)
+	{
+		if ($tag !== FALSE)
+		{
+			Kohana::log('error', 'Cache: tags are unsupported by the Xcache driver');
+			return TRUE;
+		}
+		elseif ($id !== TRUE)
+		{
+			if (xcache_isset($id))
+				return xcache_unset($id);
+
+			return FALSE;
+		}
+		else
+		{
+			// Do the login
+			$this->auth();
+			$result = TRUE;
+			for ($i = 0, $max = xcache_count(XC_TYPE_VAR); $i < $max; $i++)
+			{
+				if (xcache_clear_cache(XC_TYPE_VAR, $i) !== NULL)
+				{
+					$result = FALSE;
+					break;
+				}
+			}
+
+			// Undo the login
+			$this->auth(TRUE);
+			return $result;
+		}
+
+		return TRUE;
+	}
+
+	public function delete_expired()
+	{
+		return TRUE;
+	}
+
+	private function auth($reverse = FALSE)
+	{
+		static $backup = array();
+
+		$keys = array('PHP_AUTH_USER', 'PHP_AUTH_PW');
+
+		foreach ($keys as $key)
+		{
+			if ($reverse)
+			{
+				if (isset($backup[$key]))
+				{
+					$_SERVER[$key] = $backup[$key];
+					unset($backup[$key]);
+				}
+				else
+				{
+					unset($_SERVER[$key]);
+				}
+			}
+			else
+			{
+				$value = getenv($key);
+
+				if ( ! empty($value))
+				{
+					$backup[$key] = $value;
+				}
+
+				$_SERVER[$key] = Kohana::config('cache_xcache.'.$key);
+			}
+		}
+	}
+
+} // End Cache Xcache Driver