* This file is part of Composer.
* (c) Nils Adermann <naderman@naderman.de>
* Jordi Boggiano <j.boggiano@seld.be>
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
namespace Composer\Autoload;
* ClassLoader implements a PSR-0, PSR-4 and classmap class loader.
* $loader = new \Composer\Autoload\ClassLoader();
* // register classes with namespaces
* $loader->add('Symfony\Component', __DIR__.'/component');
* $loader->add('Symfony', __DIR__.'/framework');
* // activate the autoloader
* // to enable searching the include path (eg. for PEAR packages)
* $loader->setUseIncludePath(true);
* In this example, if you try to use a class in the Symfony\Component
* namespace or one of its children (Symfony\Component\Console for instance),
* the autoloader will first look for the class under the component/
* directory, and it will then fallback to the framework/ directory if not
* found before giving up.
* This class is loosely based on the Symfony UniversalClassLoader.
* @author Fabien Potencier <fabien@symfony.com>
* @author Jordi Boggiano <j.boggiano@seld.be>
* @see https://www.php-fig.org/psr/psr-0/
* @see https://www.php-fig.org/psr/psr-4/
private $prefixLengthsPsr4 = array();
private $prefixDirsPsr4 = array();
private $fallbackDirsPsr4 = array();
private $prefixesPsr0 = array();
private $fallbackDirsPsr0 = array();
private $useIncludePath = false;
private $classMap = array();
private $classMapAuthoritative = false;
private $missingClasses = array();
private static $registeredLoaders = array();
public function __construct($vendorDir = null)
$this->vendorDir = $vendorDir;
public function getPrefixes()
if (!empty($this->prefixesPsr0)) {
return call_user_func_array('array_merge', array_values($this->prefixesPsr0));
public function getPrefixesPsr4()
return $this->prefixDirsPsr4;
public function getFallbackDirs()
return $this->fallbackDirsPsr0;
public function getFallbackDirsPsr4()
return $this->fallbackDirsPsr4;
public function getClassMap()
* @param array $classMap Class to filename map
public function addClassMap(array $classMap)
$this->classMap = array_merge($this->classMap, $classMap);
$this->classMap = $classMap;
* Registers a set of PSR-0 directories for a given prefix, either
* appending or prepending to the ones previously set for this prefix.
* @param string $prefix The prefix
* @param array|string $paths The PSR-0 root directories
* @param bool $prepend Whether to prepend the directories
public function add($prefix, $paths, $prepend = false)
$this->fallbackDirsPsr0 = array_merge(
$this->fallbackDirsPsr0 = array_merge(
if (!isset($this->prefixesPsr0[$first][$prefix])) {
$this->prefixesPsr0[$first][$prefix] = (array) $paths;
$this->prefixesPsr0[$first][$prefix] = array_merge(
$this->prefixesPsr0[$first][$prefix]
$this->prefixesPsr0[$first][$prefix] = array_merge(
$this->prefixesPsr0[$first][$prefix],
* Registers a set of PSR-4 directories for a given namespace, either
* appending or prepending to the ones previously set for this namespace.
* @param string $prefix The prefix/namespace, with trailing '\\'
* @param array|string $paths The PSR-4 base directories
* @param bool $prepend Whether to prepend the directories
* @throws \InvalidArgumentException
public function addPsr4($prefix, $paths, $prepend = false)
// Register directories for the root namespace.
$this->fallbackDirsPsr4 = array_merge(
$this->fallbackDirsPsr4 = array_merge(
} elseif (!isset($this->prefixDirsPsr4[$prefix])) {
// Register directories for a new namespace.
$length = strlen($prefix);
if ('\\' !== $prefix[$length - 1]) {
throw new \InvalidArgumentException("A non-empty PSR-4 prefix must end with a namespace separator.");
$this->prefixLengthsPsr4[$prefix[0]][$prefix] = $length;
$this->prefixDirsPsr4[$prefix] = (array) $paths;
// Prepend directories for an already registered namespace.
$this->prefixDirsPsr4[$prefix] = array_merge(
$this->prefixDirsPsr4[$prefix]
// Append directories for an already registered namespace.
$this->prefixDirsPsr4[$prefix] = array_merge(
$this->prefixDirsPsr4[$prefix],
* Registers a set of PSR-0 directories for a given prefix,
* replacing any others previously set for this prefix.
* @param string $prefix The prefix
* @param array|string $paths The PSR-0 base directories
public function set($prefix, $paths)
$this->fallbackDirsPsr0 = (array) $paths;
$this->prefixesPsr0[$prefix[0]][$prefix] = (array) $paths;
* Registers a set of PSR-4 directories for a given namespace,
* replacing any others previously set for this namespace.
* @param string $prefix The prefix/namespace, with trailing '\\'
* @param array|string $paths The PSR-4 base directories
* @throws \InvalidArgumentException
public function setPsr4($prefix, $paths)
$this->fallbackDirsPsr4 = (array) $paths;
$length = strlen($prefix);
if ('\\' !== $prefix[$length - 1]) {
throw new \InvalidArgumentException("A non-empty PSR-4 prefix must end with a namespace separator.");
$this->prefixLengthsPsr4[$prefix[0]][$prefix] = $length;
$this->prefixDirsPsr4[$prefix] = (array) $paths;
* Turns on searching the include path for class files.
* @param bool $useIncludePath
public function setUseIncludePath($useIncludePath)
$this->useIncludePath = $useIncludePath;
* Can be used to check if the autoloader uses the include path to check
public function getUseIncludePath()
return $this->useIncludePath;
* Turns off searching the prefix and fallback directories for classes
* that have not been registered with the class map.
* @param bool $classMapAuthoritative
public function setClassMapAuthoritative($classMapAuthoritative)
$this->classMapAuthoritative = $classMapAuthoritative;
* Should class lookup fail if not found in the current class map?
public function isClassMapAuthoritative()
return $this->classMapAuthoritative;
* APCu prefix to use to cache found/not-found classes, if the extension is enabled.
* @param string|null $apcuPrefix
public function setApcuPrefix($apcuPrefix)
$this->apcuPrefix = function_exists('apcu_fetch') && filter_var(ini_get('apc.enabled'), FILTER_VALIDATE_BOOLEAN) ? $apcuPrefix : null;
* The APCu prefix in use, or null if APCu caching is not enabled.
public function getApcuPrefix()
return $this->apcuPrefix;
* Registers this instance as an autoloader.
* @param bool $prepend Whether to prepend the autoloader or not
public function register($prepend = false)
spl_autoload_register(array($this, 'loadClass'), true, $prepend);
if (null === $this->vendorDir) {
self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
unset(self::$registeredLoaders[$this->vendorDir]);
self::$registeredLoaders[$this->vendorDir] = $this;
* Unregisters this instance as an autoloader.
public function unregister()
spl_autoload_unregister(array($this, 'loadClass'));
if (null !== $this->vendorDir) {
unset(self::$registeredLoaders[$this->vendorDir]);
* Loads the given class or interface.
* @param string $class The name of the class
* @return true|null True if loaded, null otherwise
public function loadClass($class)
if ($file = $this->findFile($class)) {
* Finds the path to the file where the class is defined.
* @param string $class The name of the class
* @return string|false The path if found, false otherwise
public function findFile($class)
if (isset($this->classMap[$class])) {
return $this->classMap[$class];
if ($this->classMapAuthoritative || isset($this->missingClasses[$class])) {
if (null !== $this->apcuPrefix) {
$file = apcu_fetch($this->apcuPrefix.$class, $hit);
$file = $this->findFileWithExtension($class, '.php');
// Search for Hack files if we are running on HHVM
if (false === $file && defined('HHVM_VERSION')) {
$file = $this->findFileWithExtension($class, '.hh');
if (null !== $this->apcuPrefix) {
apcu_add($this->apcuPrefix.$class, $file);
// Remember that this class does not exist.
$this->missingClasses[$class] = true;
* Returns the currently registered loaders indexed by their corresponding vendor directories.
public static function getRegisteredLoaders()
return self::$registeredLoaders;
private function findFileWithExtension($class, $ext)
$logicalPathPsr4 = strtr($class, '\\', DIRECTORY_SEPARATOR) . $ext;
if (isset($this->prefixLengthsPsr4[$first])) {
while (false !== $lastPos = strrpos($subPath, '\\')) {
$subPath = substr($subPath, 0, $lastPos);
$search = $subPath . '\\';
if (isset($this->prefixDirsPsr4[$search])) {
$pathEnd = DIRECTORY_SEPARATOR . substr($logicalPathPsr4, $lastPos + 1);
foreach ($this->prefixDirsPsr4[$search] as $dir) {
if (file_exists($file = $dir . $pathEnd)) {
foreach ($this->fallbackDirsPsr4 as $dir) {
if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr4)) {
if (false !== $pos = strrpos($class, '\\')) {
$logicalPathPsr0 = substr($logicalPathPsr4, 0, $pos + 1)
. strtr(substr($logicalPathPsr4, $pos + 1), '_', DIRECTORY_SEPARATOR);
$logicalPathPsr0 = strtr($class, '_', DIRECTORY_SEPARATOR) . $ext;
if (isset($this->prefixesPsr0[$first])) {
foreach ($this->prefixesPsr0[$first] as $prefix => $dirs) {
if (0 === strpos($class, $prefix)) {
foreach ($dirs as $dir) {
if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
foreach ($this->fallbackDirsPsr0 as $dir) {
if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
if ($this->useIncludePath && $file = stream_resolve_include_path($logicalPathPsr0)) {
* Scope isolated include.
* Prevents access to $this/self from included files.
function includeFile($file)