Method OpenAndReadMetaData

IO/ADIOS2/vtkADIOS2CoreImageReader.cxx:323–400

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
bool vtkADIOS2CoreImageReader::OpenAndReadMetaData()
{
  // Is name valid
  if (!this->CanReadFile(this->FileName))
  {
    vtkErrorMacro("cannot read file" << this->FileName);
    return false;
  }

  // Initialize the ADIOS2 data structures
  if (!this->Impl->Adios)
  {
#if VTK_MODULE_ENABLE_VTK_ParallelMPI
    // Make sure the ADIOS subsystem is initialized before processing any
    // sort of request.
    if (!this->Controller)
    {
      vtkErrorMacro("The reader is built with MPI support but the application is not launched in "
                    "parallel mode. Abort reading.");
      return false;
    }
    vtkMPICommunicator* comm =
      static_cast<vtkMPICommunicator*>(this->Controller->GetCommunicator());

    this->Impl->Adios.reset(new adios2::ADIOS(*comm->GetMPIComm()->GetHandle()));
#else
    // Make sure the ADIOS subsystem is initialized before processing any
    // sort of request.

    this->Impl->Adios.reset(new adios2::ADIOS());
    // Before processing any request, read the meta data first
#endif
  }
  // Before processing any request, read the meta data first
  try
  {
#if IOADIOS2_BP5_RANDOM_ACCESS
    auto mode = adios2::Mode::ReadRandomAccess;
#else
    auto mode = adios2::Mode::Read;
#endif
    this->Impl->AdiosIO = this->Impl->Adios->DeclareIO("vtkADIOS2ImageRead");
    if (vtksys::SystemTools::StringEndsWith(this->FileName, ".bp") ||
      vtksys::SystemTools::StringEndsWith(this->FileName, ".bp4") ||
      vtksys::SystemTools::StringEndsWith(this->FileName, ".bp5"))
    {
      this->Impl->AdiosIO.SetEngine("BPFile");
      this->Impl->BpReader = this->Impl->AdiosIO.Open(this->FileName, mode);
    }
    else if (vtksys::SystemTools::StringEndsWith(this->FileName, "md.idx"))
    {
      this->Impl->AdiosIO.SetEngine("BP4");
      this->Impl->BpReader =
        this->Impl->AdiosIO.Open(this->FileName.substr(0, this->FileName.size() - 6), mode);
    }
    else
    {
      throw std::runtime_error("Unsupported file extension");