1<?php
2
3/*
4 * This file is part of Composer.
5 *
6 * (c) Nils Adermann <naderman@naderman.de>
7 *     Jordi Boggiano <j.boggiano@seld.be>
8 *
9 * For the full copyright and license information, please view the LICENSE
10 * file that was distributed with this source code.
11 */
12
13namespace Composer\Autoload;
14
15/**
16 * ClassLoader implements a PSR-0, PSR-4 and classmap class loader.
17 *
18 *     $loader = new \Composer\Autoload\ClassLoader();
19 *
20 *     // register classes with namespaces
21 *     $loader->add('Symfony\Component', __DIR__.'/component');
22 *     $loader->add('Symfony',           __DIR__.'/framework');
23 *
24 *     // activate the autoloader
25 *     $loader->register();
26 *
27 *     // to enable searching the include path (eg. for PEAR packages)
28 *     $loader->setUseIncludePath(true);
29 *
30 * In this example, if you try to use a class in the Symfony\Component
31 * namespace or one of its children (Symfony\Component\Console for instance),
32 * the autoloader will first look for the class under the component/
33 * directory, and it will then fallback to the framework/ directory if not
34 * found before giving up.
35 *
36 * This class is loosely based on the Symfony UniversalClassLoader.
37 *
38 * @author Fabien Potencier <fabien@symfony.com>
39 * @author Jordi Boggiano <j.boggiano@seld.be>
40 * @see    https://www.php-fig.org/psr/psr-0/
41 * @see    https://www.php-fig.org/psr/psr-4/
42 */
43class ClassLoader
44{
45    /** @var \Closure(string):void */
46    private static $includeFile;
47
48    /** @var string|null */
49    private $vendorDir;
50
51    // PSR-4
52    /**
53     * @var array<string, array<string, int>>
54     */
55    private $prefixLengthsPsr4 = array();
56    /**
57     * @var array<string, list<string>>
58     */
59    private $prefixDirsPsr4 = array();
60    /**
61     * @var list<string>
62     */
63    private $fallbackDirsPsr4 = array();
64
65    // PSR-0
66    /**
67     * List of PSR-0 prefixes
68     *
69     * Structured as array('F (first letter)' => array('Foo\Bar (full prefix)' => array('path', 'path2')))
70     *
71     * @var array<string, array<string, list<string>>>
72     */
73    private $prefixesPsr0 = array();
74    /**
75     * @var list<string>
76     */
77    private $fallbackDirsPsr0 = array();
78
79    /** @var bool */
80    private $useIncludePath = false;
81
82    /**
83     * @var array<string, string>
84     */
85    private $classMap = array();
86
87    /** @var bool */
88    private $classMapAuthoritative = false;
89
90    /**
91     * @var array<string, bool>
92     */
93    private $missingClasses = array();
94
95    /** @var string|null */
96    private $apcuPrefix;
97
98    /**
99     * @var array<string, self>
100     */
101    private static $registeredLoaders = array();
102
103    /**
104     * @param string|null $vendorDir
105     */
106    public function __construct($vendorDir = null)
107    {
108        $this->vendorDir = $vendorDir;
109        self::initializeIncludeClosure();
110    }
111
112    /**
113     * @return array<string, list<string>>
114     */
115    public function getPrefixes()
116    {
117        if (!empty($this->prefixesPsr0)) {
118            return call_user_func_array('array_merge', array_values($this->prefixesPsr0));
119        }
120
121        return array();
122    }
123
124    /**
125     * @return array<string, list<string>>
126     */
127    public function getPrefixesPsr4()
128    {
129        return $this->prefixDirsPsr4;
130    }
131
132    /**
133     * @return list<string>
134     */
135    public function getFallbackDirs()
136    {
137        return $this->fallbackDirsPsr0;
138    }
139
140    /**
141     * @return list<string>
142     */
143    public function getFallbackDirsPsr4()
144    {
145        return $this->fallbackDirsPsr4;
146    }
147
148    /**
149     * @return array<string, string> Array of classname => path
150     */
151    public function getClassMap()
152    {
153        return $this->classMap;
154    }
155
156    /**
157     * @param array<string, string> $classMap Class to filename map
158     *
159     * @return void
160     */
161    public function addClassMap(array $classMap)
162    {
163        if ($this->classMap) {
164            $this->classMap = array_merge($this->classMap, $classMap);
165        } else {
166            $this->classMap = $classMap;
167        }
168    }
169
170    /**
171     * Registers a set of PSR-0 directories for a given prefix, either
172     * appending or prepending to the ones previously set for this prefix.
173     *
174     * @param string              $prefix  The prefix
175     * @param list<string>|string $paths   The PSR-0 root directories
176     * @param bool                $prepend Whether to prepend the directories
177     *
178     * @return void
179     */
180    public function add($prefix, $paths, $prepend = false)
181    {
182        $paths = (array) $paths;
183        if (!$prefix) {
184            if ($prepend) {
185                $this->fallbackDirsPsr0 = array_merge(
186                    $paths,
187                    $this->fallbackDirsPsr0
188                );
189            } else {
190                $this->fallbackDirsPsr0 = array_merge(
191                    $this->fallbackDirsPsr0,
192                    $paths
193                );
194            }
195
196            return;
197        }
198
199        $first = $prefix[0];
200        if (!isset($this->prefixesPsr0[$first][$prefix])) {
201            $this->prefixesPsr0[$first][$prefix] = $paths;
202
203            return;
204        }
205        if ($prepend) {
206            $this->prefixesPsr0[$first][$prefix] = array_merge(
207                $paths,
208                $this->prefixesPsr0[$first][$prefix]
209            );
210        } else {
211            $this->prefixesPsr0[$first][$prefix] = array_merge(
212                $this->prefixesPsr0[$first][$prefix],
213                $paths
214            );
215        }
216    }
217
218    /**
219     * Registers a set of PSR-4 directories for a given namespace, either
220     * appending or prepending to the ones previously set for this namespace.
221     *
222     * @param string              $prefix  The prefix/namespace, with trailing '\\'
223     * @param list<string>|string $paths   The PSR-4 base directories
224     * @param bool                $prepend Whether to prepend the directories
225     *
226     * @throws \InvalidArgumentException
227     *
228     * @return void
229     */
230    public function addPsr4($prefix, $paths, $prepend = false)
231    {
232        $paths = (array) $paths;
233        if (!$prefix) {
234            // Register directories for the root namespace.
235            if ($prepend) {
236                $this->fallbackDirsPsr4 = array_merge(
237                    $paths,
238                    $this->fallbackDirsPsr4
239                );
240            } else {
241                $this->fallbackDirsPsr4 = array_merge(
242                    $this->fallbackDirsPsr4,
243                    $paths
244                );
245            }
246        } elseif (!isset($this->prefixDirsPsr4[$prefix])) {
247            // Register directories for a new namespace.
248            $length = strlen($prefix);
249            if ('\\' !== $prefix[$length - 1]) {
250                throw new \InvalidArgumentException("A non-empty PSR-4 prefix must end with a namespace separator.");
251            }
252            $this->prefixLengthsPsr4[$prefix[0]][$prefix] = $length;
253            $this->prefixDirsPsr4[$prefix] = $paths;
254        } elseif ($prepend) {
255            // Prepend directories for an already registered namespace.
256            $this->prefixDirsPsr4[$prefix] = array_merge(
257                $paths,
258                $this->prefixDirsPsr4[$prefix]
259            );
260        } else {
261            // Append directories for an already registered namespace.
262            $this->prefixDirsPsr4[$prefix] = array_merge(
263                $this->prefixDirsPsr4[$prefix],
264                $paths
265            );
266        }
267    }
268
269    /**
270     * Registers a set of PSR-0 directories for a given prefix,
271     * replacing any others previously set for this prefix.
272     *
273     * @param string              $prefix The prefix
274     * @param list<string>|string $paths  The PSR-0 base directories
275     *
276     * @return void
277     */
278    public function set($prefix, $paths)
279    {
280        if (!$prefix) {
281            $this->fallbackDirsPsr0 = (array) $paths;
282        } else {
283            $this->prefixesPsr0[$prefix[0]][$prefix] = (array) $paths;
284        }
285    }
286
287    /**
288     * Registers a set of PSR-4 directories for a given namespace,
289     * replacing any others previously set for this namespace.
290     *
291     * @param string              $prefix The prefix/namespace, with trailing '\\'
292     * @param list<string>|string $paths  The PSR-4 base directories
293     *
294     * @throws \InvalidArgumentException
295     *
296     * @return void
297     */
298    public function setPsr4($prefix, $paths)
299    {
300        if (!$prefix) {
301            $this->fallbackDirsPsr4 = (array) $paths;
302        } else {
303            $length = strlen($prefix);
304            if ('\\' !== $prefix[$length - 1]) {
305                throw new \InvalidArgumentException("A non-empty PSR-4 prefix must end with a namespace separator.");
306            }
307            $this->prefixLengthsPsr4[$prefix[0]][$prefix] = $length;
308            $this->prefixDirsPsr4[$prefix] = (array) $paths;
309        }
310    }
311
312    /**
313     * Turns on searching the include path for class files.
314     *
315     * @param bool $useIncludePath
316     *
317     * @return void
318     */
319    public function setUseIncludePath($useIncludePath)
320    {
321        $this->useIncludePath = $useIncludePath;
322    }
323
324    /**
325     * Can be used to check if the autoloader uses the include path to check
326     * for classes.
327     *
328     * @return bool
329     */
330    public function getUseIncludePath()
331    {
332        return $this->useIncludePath;
333    }
334
335    /**
336     * Turns off searching the prefix and fallback directories for classes
337     * that have not been registered with the class map.
338     *
339     * @param bool $classMapAuthoritative
340     *
341     * @return void
342     */
343    public function setClassMapAuthoritative($classMapAuthoritative)
344    {
345        $this->classMapAuthoritative = $classMapAuthoritative;
346    }
347
348    /**
349     * Should class lookup fail if not found in the current class map?
350     *
351     * @return bool
352     */
353    public function isClassMapAuthoritative()
354    {
355        return $this->classMapAuthoritative;
356    }
357
358    /**
359     * APCu prefix to use to cache found/not-found classes, if the extension is enabled.
360     *
361     * @param string|null $apcuPrefix
362     *
363     * @return void
364     */
365    public function setApcuPrefix($apcuPrefix)
366    {
367        $this->apcuPrefix = function_exists('apcu_fetch') && filter_var(ini_get('apc.enabled'), FILTER_VALIDATE_BOOLEAN) ? $apcuPrefix : null;
368    }
369
370    /**
371     * The APCu prefix in use, or null if APCu caching is not enabled.
372     *
373     * @return string|null
374     */
375    public function getApcuPrefix()
376    {
377        return $this->apcuPrefix;
378    }
379
380    /**
381     * Registers this instance as an autoloader.
382     *
383     * @param bool $prepend Whether to prepend the autoloader or not
384     *
385     * @return void
386     */
387    public function register($prepend = false)
388    {
389        spl_autoload_register(array($this, 'loadClass'), true, $prepend);
390
391        if (null === $this->vendorDir) {
392            return;
393        }
394
395        if ($prepend) {
396            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
397        } else {
398            unset(self::$registeredLoaders[$this->vendorDir]);
399            self::$registeredLoaders[$this->vendorDir] = $this;
400        }
401    }
402
403    /**
404     * Unregisters this instance as an autoloader.
405     *
406     * @return void
407     */
408    public function unregister()
409    {
410        spl_autoload_unregister(array($this, 'loadClass'));
411
412        if (null !== $this->vendorDir) {
413            unset(self::$registeredLoaders[$this->vendorDir]);
414        }
415    }
416
417    /**
418     * Loads the given class or interface.
419     *
420     * @param  string    $class The name of the class
421     * @return true|null True if loaded, null otherwise
422     */
423    public function loadClass($class)
424    {
425        if ($file = $this->findFile($class)) {
426            $includeFile = self::$includeFile;
427            $includeFile($file);
428
429            return true;
430        }
431
432        return null;
433    }
434
435    /**
436     * Finds the path to the file where the class is defined.
437     *
438     * @param string $class The name of the class
439     *
440     * @return string|false The path if found, false otherwise
441     */
442    public function findFile($class)
443    {
444        // class map lookup
445        if (isset($this->classMap[$class])) {
446            return $this->classMap[$class];
447        }
448        if ($this->classMapAuthoritative || isset($this->missingClasses[$class])) {
449            return false;
450        }
451        if (null !== $this->apcuPrefix) {
452            $file = apcu_fetch($this->apcuPrefix.$class, $hit);
453            if ($hit) {
454                return $file;
455            }
456        }
457
458        $file = $this->findFileWithExtension($class, '.php');
459
460        // Search for Hack files if we are running on HHVM
461        if (false === $file && defined('HHVM_VERSION')) {
462            $file = $this->findFileWithExtension($class, '.hh');
463        }
464
465        if (null !== $this->apcuPrefix) {
466            apcu_add($this->apcuPrefix.$class, $file);
467        }
468
469        if (false === $file) {
470            // Remember that this class does not exist.
471            $this->missingClasses[$class] = true;
472        }
473
474        return $file;
475    }
476
477    /**
478     * Returns the currently registered loaders keyed by their corresponding vendor directories.
479     *
480     * @return array<string, self>
481     */
482    public static function getRegisteredLoaders()
483    {
484        return self::$registeredLoaders;
485    }
486
487    /**
488     * @param  string       $class
489     * @param  string       $ext
490     * @return string|false
491     */
492    private function findFileWithExtension($class, $ext)
493    {
494        // PSR-4 lookup
495        $logicalPathPsr4 = strtr($class, '\\', DIRECTORY_SEPARATOR) . $ext;
496
497        $first = $class[0];
498        if (isset($this->prefixLengthsPsr4[$first])) {
499            $subPath = $class;
500            while (false !== $lastPos = strrpos($subPath, '\\')) {
501                $subPath = substr($subPath, 0, $lastPos);
502                $search = $subPath . '\\';
503                if (isset($this->prefixDirsPsr4[$search])) {
504                    $pathEnd = DIRECTORY_SEPARATOR . substr($logicalPathPsr4, $lastPos + 1);
505                    foreach ($this->prefixDirsPsr4[$search] as $dir) {
506                        if (file_exists($file = $dir . $pathEnd)) {
507                            return $file;
508                        }
509                    }
510                }
511            }
512        }
513
514        // PSR-4 fallback dirs
515        foreach ($this->fallbackDirsPsr4 as $dir) {
516            if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr4)) {
517                return $file;
518            }
519        }
520
521        // PSR-0 lookup
522        if (false !== $pos = strrpos($class, '\\')) {
523            // namespaced class name
524            $logicalPathPsr0 = substr($logicalPathPsr4, 0, $pos + 1)
525                . strtr(substr($logicalPathPsr4, $pos + 1), '_', DIRECTORY_SEPARATOR);
526        } else {
527            // PEAR-like class name
528            $logicalPathPsr0 = strtr($class, '_', DIRECTORY_SEPARATOR) . $ext;
529        }
530
531        if (isset($this->prefixesPsr0[$first])) {
532            foreach ($this->prefixesPsr0[$first] as $prefix => $dirs) {
533                if (0 === strpos($class, $prefix)) {
534                    foreach ($dirs as $dir) {
535                        if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
536                            return $file;
537                        }
538                    }
539                }
540            }
541        }
542
543        // PSR-0 fallback dirs
544        foreach ($this->fallbackDirsPsr0 as $dir) {
545            if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
546                return $file;
547            }
548        }
549
550        // PSR-0 include paths.
551        if ($this->useIncludePath && $file = stream_resolve_include_path($logicalPathPsr0)) {
552            return $file;
553        }
554
555        return false;
556    }
557
558    /**
559     * @return void
560     */
561    private static function initializeIncludeClosure()
562    {
563        if (self::$includeFile !== null) {
564            return;
565        }
566
567        /**
568         * Scope isolated include.
569         *
570         * Prevents access to $this/self from included files.
571         *
572         * @param  string $file
573         * @return void
574         */
575        self::$includeFile = \Closure::bind(static function($file) {
576            include $file;
577        }, null, null);
578    }
579}
580