Method RequestData

Filters/Parallel/vtkHyperTreeGridGhostCellsGenerator.cxx:175–272

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

//------------------------------------------------------------------------------
int vtkHyperTreeGridGhostCellsGenerator::RequestData(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  this->UpdateProgress(0.);

  vtkInformation* info = outputVector->GetInformationObject(0);
  int currentPiece = info->Get(vtkStreamingDemandDrivenPipeline::UPDATE_PIECE_NUMBER());

  // Make sure input is either a HTG or a PartitionedDataSet that contains a HTG piece.
  vtkHyperTreeGrid* inputHTG = vtkHyperTreeGrid::GetData(inputVector[0], 0);
  vtkPartitionedDataSet* inputPDS = vtkPartitionedDataSet::GetData(inputVector[0], 0);

  if (!inputPDS && !inputHTG)
  {
    vtkErrorMacro("Input data is neither HTG or PartitionedDataSet. Cannot proceed with ghost cell "
                  "generation.");
    return 0;
  }

  vtkHyperTreeGrid* outputHTG = vtkHyperTreeGrid::GetData(outputVector, 0);
  vtkPartitionedDataSet* outputPDS = vtkPartitionedDataSet::GetData(outputVector, 0);
  if (outputPDS)
  {
    outputPDS->CopyStructure(inputPDS);
  }

  // When the filter receives a PartitionedDataSet, the data for the current rank can be in either
  // partition, depending on the data generation method. We survey the partitions to find the one
  // that contains the actual data. There should be exactly one non-null HTG partition in each
  // piece. If we find multiple, the HTG structure is not capable of merging multiple grids, so we
  // simply use the last one.
  if (inputPDS && outputPDS)
  {
    for (unsigned int partId = 0; partId < inputPDS->GetNumberOfPartitions(); partId++)
    {
      auto partHTG = vtkHyperTreeGrid::SafeDownCast(inputPDS->GetPartitionAsDataObject(partId));
      if (partHTG)
      {
        if (inputHTG)
        {
          vtkWarningMacro("Found more than one non-null HTG in the partitioned dataset for piece "
            << currentPiece << ". Generating ghost data only for partition " << partId);
        }
        inputHTG = partHTG;
        vtkNew<vtkHyperTreeGrid> newOutputHTG;
        outputPDS->SetPartition(partId, newOutputHTG);
        outputHTG = newOutputHTG; // Not dangling, outputPDS maintains a reference.
      }
    }
  }

  if (!outputHTG && !outputPDS)
  {
    vtkErrorMacro("No output available. Cannot proceed with hyper tree grid algorithm.");
    return 0;
  }

  if (!inputHTG)