Function stringToStreampos

src/openms/source/FORMAT/HANDLERS/IndexedMzMLDecoder.cpp:27–63

  namespace IndexedMzMLUtils
  {
    std::streampos stringToStreampos(const std::string& s)
    {
      // Try to cast the string to a type that can hold the integer value
      // stored in the std::streampos type (which can vary from 32 to 128 bits
      // depending on the system).
      //
      // long long has a minimal size of 64 bits and can address a range up to
      // 16 Exbibit (or 2 Exbibyte), we can hopefully expect our files to be
      // smaller than an Exabyte and should be safe.
      std::streampos res;
      try
      {

        res = boost::lexical_cast< unsigned long long >(s);
        // TESTING CAST: res = (int) res; // use this only when emulating 32 bit systems

      }
      catch (boost::bad_lexical_cast&)
      {
        std::cerr << "Trying to convert corrupted / unreadable value to std::streampos : " << s << std::endl;
        std::cerr << "This can also happen if the value exceeds 63 bits, please check your input." << std::endl;
        throw Exception::ConversionError(__FILE__, __LINE__, OPENMS_PRETTY_FUNCTION,
            String("Could not convert string '") + s + "' to a 64 bit integer.");
      }

      // Check if the value can fit into std::streampos
      if ( std::abs( boost::lexical_cast< long double >(s) - res) > 0.1)
      {
        std::cerr << "Your system may not support addressing a file of this size,"
          << " only addresses that fit into a " << sizeof(std::streamsize)*8 <<
          " bit integer are supported on your system." << std::endl;
        throw Exception::ConversionError(__FILE__, __LINE__, OPENMS_PRETTY_FUNCTION,
            String("Could not convert string '") + s + "' to an integer on your system.");
      }

      return res;
    }
  }

  int IndexedMzMLDecoder::parseOffsets(const String& filename, std::streampos indexoffset, OffsetVector& spectra_offsets, OffsetVector& chromatograms_offsets)