lock (O)
            {
                try
                {
                    if (File.Exists(wholePath))
                    {
                        _stream = new FileStream(wholePath, FileMode.Open);
                        MD5 mdValue = new MD5CryptoServiceProvider();

                        _md5FileName = wholePath.Remove(wholePath.LastIndexOf(".")) + ".md5";

                        byte[] cryptResult = mdValue.ComputeHash(_stream);
                        var b = new StringBuilder();
                        for (int i = 0; i < cryptResult.Length; i++)
                            b.Append(cryptResult[i].ToString("x2"));

                        if(!File.Exists(_md5FileName))
                             File.Create(_md5FileName ).Close();

                        _inputStream = new StreamWriter(_md5FileName, false);
                        _inputStream.WriteLine(b.ToString());
                        _inputStream.Flush();
                    }
                }
                catch (Exception e)
                {
                    Console.WriteLine(e.Message);
                }
                finally
                {
                    if(_stream != null)
                        _stream.Close();
                    if(_inputStream != null)
                        _inputStream.Close();
                }
            }