phpBB/phpbb/class_loader.php


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164

<?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 existance 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;
			}
		}
	}
}