= stat(::File.join(path, basename))
        next unless stat

        url = ::File.join(*url_head + [Utils.escape_path(basename)])
        mtime = stat.mtime.httpdate
        if stat.directory?
          type = 'directory'
          size = '-'
          url << '/'
          if basename == '..'
            basename = 'Parent Directory'
          else
            basename << '/'
          end
        else
          type = Mime.mime_type(::File.extname(basename))
          size = filesize_format(stat.size)
        end

        [ url, basename, size, type, mtime ]
      end)

      [ 200, { CONTENT_TYPE => 'text/html; charset=utf-8' }, body ]
    end

    # File::Stat for the given path, but return nil for missing/bad entries.
    def stat(path)
      ::File.stat(path)
    rescue Errno::ENOENT, Errno::ELOOP
      return nil
    end

    # Rack response to use for files and directories under the root.
    # Unreadable and non-file, non-directory entries will get a 404 response.
    def list_path(env, path, path_info, script_name)
      if (stat = stat(path)) && stat.readable?
        return @app.call(env) if stat.file?
        return list_directory(path_info, path, script_name) if stat.directory?
      end

      entity_not_found(path_info)
    end

    # Rack response to use for unreadable and non-file, non-directory entries.
    def entity_not_found(path_info)
      body = "Entity not found: #{path_info}\n"
      [404, { CONTENT_TYPE => "text/plain",
        CONTENT_LENGTH => body.bytesize.to_s,
        "X-Cascade" => "pass" }, [body]]
    end

    # Stolen from Ramaze
    FILESIZE_FORMAT = [
      ['%.1fT', 1 << 40],
      ['%.1fG', 1 << 30],
      ['%.1fM', 1 << 20],
      ['%.1fK', 1 << 10],
    ]

    # Provide human readable file sizes
    def filesize_format(int)
      FILESIZE_FORMAT.each do |format, size|
        return format % (int.to_f / size) if int >= size
      end

      "#{int}B"
    end
  end
end
