<?php
/**
*
* This file is part of the phpBB Forum Software package.
*
* @copyright (c) phpBB Limited <https://www.phpbb.com>
* @license GNU General Public License, version 2 (GPL-2.0)
*
* For full copyright and license information, please see
* the docs/CREDITS.txt file.
*
*/
namespace phpbb;
/**
* 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.
*/
class class_loader
{
private $namespace;
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 $namespace Required namespace 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\driver_interface $cache An implementation of the phpBB cache interface.
*/
public function __construct($namespace, $path, $php_ext = 'php', \phpbb\cache\driver\driver_interface $cache = null)
{
if ($namespace[0] !== '\\')
{
$namespace = '\\' . $namespace;
}
$this->namespace = $namespace;
$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 existence of every
* directory in the class name every time.
*
* @param \phpbb\cache\driver\driver_interface $cache An implementation of the phpBB cache interface.
*/
public function set_cache(\phpbb\cache\driver\driver_interface $cache = null)
{
if ($cache)
{
$this->cached_paths = $cache->get('class_loader_' . str_replace('\\', '__', $this->namespace));
if ($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 $class The class name to resolve, must be in the
* namespace the loader was constructed with.
* Has to begin with \
* @return string|bool A relative path to the file containing the
* class or false if looking it up failed.
*/
public function resolve_path($class)
{
if (isset($this->cached_paths[$class]))
{
return $this->path . $this->cached_paths[$class] . '.' . $this->php_ext;
}
if (!preg_match('/^' . preg_quote($this->namespace, '/') . '[a-zA-Z0-9_\\\\]+$/', $class))
{
return false;
}
$relative_path = str_replace('\\', '/', substr($class, strlen($this->namespace)));
if (!file_exists($this->path . $relative_path . '.' . $this->php_ext))
{
return false;
}
if ($this->cache)
{
$this->cached_paths[$class] = $relative_path;
$this->cache->put('class_loader_' . str_replace('\\', '__', $this->namespace), $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)
{
// In general $class is not supposed to contain a leading backslash,
// but sometimes it does. See tickets PHP-50731 and HHVM-1840.
if ($class[0] !== '\\')
{
$class = '\\' . $class;
}
if (substr($class, 0, strlen($this->namespace)) === $this->namespace)
{
$path = $this->resolve_path($class);
if ($path)
{
require $path;
}
}
}
}