text: <?php
  
  /*
   * 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
   *     $loader->register();
   *
   *     // 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    http://www.php-fig.org/psr/psr-0/
   * @see    http://www.php-fig.org/psr/psr-4/
   */
  class ClassLoader
  {
      // PSR-4
      private $prefixLengthsPsr4 = array();
      private $prefixDirsPsr4 = array();
      private $fallbackDirsPsr4 = array();
  
      // PSR-0
      private $prefixesPsr0 = array();
      private $fallbackDirsPsr0 = array();
  
      private $useIncludePath = false;
      private $classMap = array();
      private $classMapAuthoritative = false;
      private $missingClasses = array();
      private $apcuPrefix;
  
      public function getPrefixes()
      {
          if (!empty($this->prefixesPsr0)) {
              return call_user_func_array('array_merge', $this->prefixesPsr0);
          }
  
          return array();
      }
  
      public function getPrefixesPsr4()
      {
          return $this->prefixDirsPsr4;
      }
  
      public function getFallbackDirs()
      {
          return $this->fallbackDirsPsr0;
      }
  
      public function getFallbackDirsPsr4()
      {
          return $this->fallbackDirsPsr4;
      }
  
      public function getClassMap()
      {
          return $this->classMap;
      }
  
      /**
       * @param array $classMap Class to filename map
       */
      public function addClassMap(array $classMap)
      {
          if ($this->classMap) {
              $this->classMap = array_merge($this->classMap, $classMap);
          } else {
              $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, $prepend = false)
      {
          if (!$prefix) {
              if ($prepend) {
                  $this->fallbackDirsPsr0 = array_merge(
                      (array) $paths,
                      $this->fallbackDirsPsr0
                  );
              } else {
                  $this->fallbackDirsPsr0 = array_merge(
                      $this->fallbackDirsPsr0,
                      (array) $paths
                  );
              }
  
              return;
          }
  
          $first = $prefix[0];
          if (!isset($this->prefixesPsr0[$first][$prefix])) {
              $this->prefixesPsr0[$first][$prefix] = (array) $paths;
  
              return;
          }
          if ($prepend) {
              $this->prefixesPsr0[$first][$prefix] = array_merge(
                  (array) $paths,
                  $this->prefixesPsr0[$first][$prefix]
              );
          } else {
              $this->prefixesPsr0[$first][$prefix] = array_merge(
                  $this->prefixesPsr0[$first][$prefix],
                  (array) $paths
              );
          }
      }
  
      /**
       * 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, $prepend = false)
      {
          if (!$prefix) {
              // Register directories for the root namespace.
              if ($prepend) {
                  $this->fallbackDirsPsr4 = array_merge(
                      (array) $paths,
                      $this->fallbackDirsPsr4
                  );
              } else {
                  $this->fallbackDirsPsr4 = array_merge(
                      $this->fallbackDirsPsr4,
                      (array) $paths
                  );
              }
          } elseif (!isset($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) $paths;
          } elseif ($prepend) {
              // Prepend directories for an already registered namespace.
              $this->prefixDirsPsr4[$prefix] = array_merge(
                  (array) $paths,
                  $this->prefixDirsPsr4[$prefix]
              );
          } else {
              // Append directories for an already registered namespace.
              $this->prefixDirsPsr4[$prefix] = array_merge(
                  $this->prefixDirsPsr4[$prefix],
                  (array) $paths
              );
          }
      }
  
      /**
       * 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, $paths)
      {
          if (!$prefix) {
              $this->fallbackDirsPsr0 = (array) $paths;
          } else {
              $this->prefixesPsr0[$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, $paths)
      {
          if (!$prefix) {
              $this->fallbackDirsPsr4 = (array) $paths;
          } else {
              $length = strlen($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
       * for classes.
       *
       * @return bool
       */
      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?
       *
       * @return bool
       */
      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.
       *
       * @return string|null
       */
      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);
      }
  
      /**
       * Unregisters this instance as an autoloader.
       */
      public function unregister()
      {
          spl_autoload_unregister(array($this, 'loadClass'));
      }
  
      /**
       * Loads the given class or interface.
       *
       * @param  string    $class The name of the class
       * @return bool|null True if loaded, null otherwise
       */
      public function loadClass($class)
      {
          if ($file = $this->findFile($class)) {
              includeFile($file);
  
              return true;
          }
      }
  
      /**
       * 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)
      {
          // class map lookup
          if (isset($this->classMap[$class])) {
              return $this->classMap[$class];
          }
          if ($this->classMapAuthoritative || isset($this->missingClasses[$class])) {
              return false;
          }
          if (null !== $this->apcuPrefix) {
              $file = apcu_fetch($this->apcuPrefix.$class, $hit);
              if ($hit) {
                  return $file;
              }
          }
  
          $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);
          }
  
          if (false === $file) {
              // Remember that this class does not exist.
              $this->missingClasses[$class] = true;
          }
  
          return $file;
      }
  
      private function findFileWithExtension($class, $ext)
      {
          // PSR-4 lookup
          $logicalPathPsr4 = strtr($class, '\\', DIRECTORY_SEPARATOR) . $ext;
  
          $first = $class[0];
          if (isset($this->prefixLengthsPsr4[$first])) {
              $subPath = $class;
              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)) {
                              return $file;
                          }
                      }
                  }
              }
          }
  
          // PSR-4 fallback dirs
          foreach ($this->fallbackDirsPsr4 as $dir) {
              if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr4)) {
                  return $file;
              }
          }
  
          // PSR-0 lookup
          if (false !== $pos = strrpos($class, '\\')) {
              // namespaced class name
              $logicalPathPsr0 = substr($logicalPathPsr4, 0, $pos + 1)
                  . strtr(substr($logicalPathPsr4, $pos + 1), '_', DIRECTORY_SEPARATOR);
          } else {
              // PEAR-like class name
              $logicalPathPsr0 = strtr($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)) {
                              return $file;
                          }
                      }
                  }
              }
          }
  
          // PSR-0 fallback dirs
          foreach ($this->fallbackDirsPsr0 as $dir) {
              if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
                  return $file;
              }
          }
  
          // PSR-0 include paths.
          if ($this->useIncludePath && $file = stream_resolve_include_path($logicalPathPsr0)) {
              return $file;
          }
  
          return false;
      }
  }
  
  /**
   * Scope isolated include.
   *
   * Prevents access to $this/self from included files.
   */
  function includeFile($file)
  {
      include $file;
  }
  