Method Partition

Common/ExecutionModel/vtkExtentRCBPartitioner.cxx:58–123

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

//------------------------------------------------------------------------------
void vtkExtentRCBPartitioner::Partition()
{
  // Short-circuit here since the given global extent has already been
  // partitioned
  if (this->ExtentIsPartitioned)
  {
    return;
  }

  // STEP 0: Get the data description according to the given global extent
  this->AcquireDataDescription();
  if (this->DataDescription == vtkStructuredData::VTK_STRUCTURED_EMPTY ||
    this->DataDescription == vtkStructuredData::VTK_STRUCTURED_SINGLE_POINT)
  {
    return;
  }

  // STEP 1: Insert the global extent to the workQueue
  vtkPriorityQueue* wrkQueue = vtkPriorityQueue::New();
  assert("pre: work queue is nullptr" && (wrkQueue != nullptr));

  this->AddExtent(this->GlobalExtent);
  wrkQueue->Insert(this->GetNumberOfNodes(this->GlobalExtent), 0);

  int ex[6]; // temporary buffer to store the current extent
  int s1[6]; // temporary buffer to store the sub-extent s1
  int s2[6]; // temporary buffer to store the sub-extent s2

  // STEP 2: Loop until number of partitions is attained
  while (this->NumExtents < this->NumberOfPartitions)
  {
    vtkIdType extentIdx = wrkQueue->Pop(wrkQueue->GetNumberOfItems() - 1);
    this->GetExtent(extentIdx, ex);
    int ldim = this->GetLongestDimension(ex);

    this->SplitExtent(ex, s1, s2, ldim);
    this->ReplaceExtent(extentIdx, s1);
    this->AddExtent(s2);

    wrkQueue->Insert(this->GetNumberOfNodes(s1), extentIdx);
    wrkQueue->Insert(this->GetNumberOfNodes(s2), this->NumExtents - 1);
  }

  // STEP 3: Clear priority data-structures
  wrkQueue->Delete();

  // STEP 4: Loop through all the extents and add ghost layers
  if (this->NumberOfGhostLayers > 0)
  {
    int ext[6];
    for (int i = 0; i < this->NumExtents; ++i)
    {
      this->GetExtent(i, ext);
      this->ExtendGhostLayers(ext);
      this->ReplaceExtent(i, ext);
    } // END for all extents
  }