class Twig_Loader_Filesystem

class Twig_Loader_Filesystem implements Twig_LoaderInterface {
  protected $paths;
  protected $cache;

  /**
   * Constructor.
   *
   * @param string|array $paths A path or an array of paths where to look for templates
   */
  public function __construct($paths) {
    $this
      ->setPaths($paths);
  }

  /**
   * Returns the paths to the templates.
   *
   * @return array The array of paths where to look for templates
   */
  public function getPaths() {
    return $this->paths;
  }

  /**
   * Sets the paths where templates are stored.
   *
   * @param string|array $paths A path or an array of paths where to look for templates
   */
  public function setPaths($paths) {
    if (!is_array($paths)) {
      $paths = array(
        $paths,
      );
    }
    $this->paths = array();
    foreach ($paths as $path) {
      $this
        ->addPath($path);
    }
  }

  /**
   * Adds a path where templates are stored.
   *
   * @param string $path A path where to look for templates
   */
  public function addPath($path) {

    // invalidate the cache
    $this->cache = array();
    if (!is_dir($path)) {
      throw new Twig_Error_Loader(sprintf('The "%s" directory does not exist.', $path));
    }
    $this->paths[] = rtrim($path, '/\\');
  }

  /**
   * Gets the source code of a template, given its name.
   *
   * @param string $name The name of the template to load
   *
   * @return string The template source code
   */
  public function getSource($name) {
    return file_get_contents($this
      ->findTemplate($name));
  }

  /**
   * Gets the cache key to use for the cache for a given template name.
   *
   * @param string $name The name of the template to load
   *
   * @return string The cache key
   */
  public function getCacheKey($name) {
    return $this
      ->findTemplate($name);
  }

  /**
   * Returns true if the template is still fresh.
   *
   * @param string    $name The template name
   * @param timestamp $time The last modification time of the cached template
   */
  public function isFresh($name, $time) {
    return filemtime($this
      ->findTemplate($name)) <= $time;
  }
  protected function findTemplate($name) {

    // normalize name
    $name = preg_replace('#/{2,}#', '/', strtr($name, '\\', '/'));
    if (isset($this->cache[$name])) {
      return $this->cache[$name];
    }
    $this
      ->validateName($name);
    foreach ($this->paths as $path) {
      if (is_file($path . '/' . $name)) {
        return $this->cache[$name] = $path . '/' . $name;
      }
    }
    throw new Twig_Error_Loader(sprintf('Unable to find template "%s" (looked into: %s).', $name, implode(', ', $this->paths)));
  }
  protected function validateName($name) {
    if (false !== strpos($name, "\0")) {
      throw new Twig_Error_Loader('A template name cannot contain NUL bytes.');
    }
    $parts = explode('/', $name);
    $level = 0;
    foreach ($parts as $part) {
      if ('..' === $part) {
        --$level;
      }
      elseif ('.' !== $part) {
        ++$level;
      }
      if ($level < 0) {
        throw new Twig_Error_Loader(sprintf('Looks like you try to load a template outside configured directories (%s).', $name));
      }
    }
  }

}