1 files changed, 170 insertions, 0 deletions
diff --git a/phpBB/includes/class_loader.php b/phpBB/includes/class_loader.php
new file mode 100644
index 0000000000..02a2d584dc
--- /dev/null
+++ b/phpBB/includes/class_loader.php
@@ -0,0 +1,170 @@
+<?php
+/**
+*
+* @package phpBB3
+* @copyright (c) 2005 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* The class loader resolves class names to file system paths and loads them if
+* necessary.
+*
+* Classes have to be of the form phpbb_(dir_)*(classpart_)*, so directory names
+* must never contain underscores. Example: phpbb_dir_subdir_class_name is a
+* valid class name, while phpbb_dir_sub_dir_class_name is not.
+*
+* If every part of the class name is a directory, the last directory name is
+* also used as the filename, e.g. phpbb_dir would resolve to dir/dir.php.
+*
+* @package phpBB3
+*/
+class phpbb_class_loader
+{
+	private $prefix;
+	private $path;
+	private $php_ext;
+	private $cache;
+
+	/**
+	* A map of looked up class names to paths relative to $this->path.
+	* This map is stored in cache and looked up if the cache is available.
+	*
+	* @var array
+	*/
+	private $cached_paths = array();
+
+	/**
+	* Creates a new phpbb_class_loader, which loads files with the given
+	* file extension from the given path.
+	*
+	* @param string $prefix  Required class name prefix for files to be loaded
+	* @param string $path    Directory to load files from
+	* @param string $php_ext The file extension for PHP files
+	* @param phpbb_cache_driver_interface $cache An implementation of the phpBB cache interface.
+	*/
+	public function __construct($prefix, $path, $php_ext = 'php', phpbb_cache_driver_interface $cache = null)
+	{
+		$this->prefix = $prefix;
+		$this->path = $path;
+		$this->php_ext = $php_ext;
+
+		$this->set_cache($cache);
+	}
+
+	/**
+	* Provide the class loader with a cache to store paths. If set to null, the
+	* the class loader will resolve paths by checking for the existance of every
+	* directory in the class name every time.
+	*
+	* @param phpbb_cache_driver_interface $cache An implementation of the phpBB cache interface.
+	*/
+	public function set_cache(phpbb_cache_driver_interface $cache = null)
+	{
+		if ($cache)
+		{
+			$this->cached_paths = $cache->get('class_loader_' . $this->prefix);
+
+			if ($this->cached_paths === false)
+			{
+				$this->cached_paths = array();
+			}
+		}
+
+		$this->cache = $cache;
+	}
+
+	/**
+	* Registers the class loader as an autoloader using SPL.
+	*/
+	public function register()
+	{
+		spl_autoload_register(array($this, 'load_class'));
+	}
+
+	/**
+	* Removes the class loader from the SPL autoloader stack.
+	*/
+	public function unregister()
+	{
+		spl_autoload_unregister(array($this, 'load_class'));
+	}
+
+	/**
+	* Resolves a phpBB class name to a relative path which can be included.
+	*
+	* @param string       $class The class name to resolve, must have a phpbb_
+	*                            prefix
+	* @return string|bool        A relative path to the file containing the
+	*                            class or false if looking it up failed.
+	*/
+	public function resolve_path($class)
+	{
+		if (isset($this->cached_paths[$class]))
+		{
+			return $this->path . $this->cached_paths[$class] . '.' . $this->php_ext;
+		}
+
+		if (!preg_match('/^' . $this->prefix . '[a-zA-Z0-9_]+$/', $class))
+		{
+			return false;
+		}
+
+		$parts = explode('_', substr($class, strlen($this->prefix)));
+
+		$dirs = '';
+
+		for ($i = 0, $n = sizeof($parts); $i < $n && is_dir($this->path . $dirs . $parts[$i]); $i++)
+		{
+			$dirs .= $parts[$i] . '/';
+		}
+
+		// no file name left => use last dir name as file name
+		if ($i == sizeof($parts))
+		{
+			$parts[] = $parts[$i - 1];
+		}
+
+		$relative_path = $dirs . implode(array_slice($parts, $i, sizeof($parts) - $i), '_');
+
+		if (!file_exists($this->path . $relative_path . '.' . $this->php_ext))
+		{
+			return false;
+		}
+
+		if ($this->cache)
+		{
+			$this->cached_paths[$class] = $relative_path;
+			$this->cache->put('class_loader_' . $this->prefix, $this->cached_paths);
+		}
+
+		return $this->path . $relative_path . '.' . $this->php_ext;
+	}
+
+	/**
+	* Resolves a class name to a path and then includes it.
+	*
+	* @param string $class The class name which is being loaded.
+	*/
+	public function load_class($class)
+	{
+		if (substr($class, 0, strlen($this->prefix)) === $this->prefix)
+		{
+			$path = $this->resolve_path($class);
+
+			if ($path)
+			{
+				require $path;
+			}
+		}
+	}
+}