Method ReorganizeData

Filters/Parallel/vtkPExtractDataArraysOverTime.cxx:108–206

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//------------------------------------------------------------------------------
void vtkPExtractDataArraysOverTime::ReorganizeData(vtkMultiBlockDataSet* dataset)
{
  // 1. Send all blocks to 0.
  // 2. Rank 0 then reorganizes blocks. This is done as follows:
  //    i. If blocks form different ranks have same names, then we check if they
  //       are referring to the same global-id. If so, the tables are merged
  //       into one. If not, we the tables separately, with their names
  //       uniquified with rank number.
  // 3. Rank 0 send info about number blocks and their names to everyone
  // 4. Satellites, then, simply initialize their output to and make it match
  //    the structure reported by rank 0.

  const int myRank = this->Controller->GetLocalProcessId();
  const int numRanks = this->Controller->GetNumberOfProcesses();
  if (myRank != 0)
  {
    std::vector<vtkSmartPointer<vtkDataObject>> recvBuffer;
    this->Controller->Gather(dataset, recvBuffer, 0);

    vtkMultiProcessStream stream;
    this->Controller->Broadcast(stream, 0);

    dataset->Initialize();
    while (!stream.Empty())
    {
      std::string name;
      stream >> name;

      auto idx = dataset->GetNumberOfBlocks();
      dataset->SetBlock(idx, nullptr);
      dataset->GetMetaData(idx)->Set(vtkCompositeDataSet::NAME(), name.c_str());
    }
  }
  else
  {
    std::vector<vtkSmartPointer<vtkDataObject>> recvBuffer;
    this->Controller->Gather(dataset, recvBuffer, 0);

    assert(static_cast<int>(recvBuffer.size()) == numRanks);

    recvBuffer[myRank] = dataset;

    std::map<std::string, std::map<int, vtkSmartPointer<vtkTable>>> collection;
    for (int rank = 0; rank < numRanks; ++rank)
    {
      if (auto mb = vtkMultiBlockDataSet::SafeDownCast(recvBuffer[rank]))
      {
        for (unsigned int cc = 0, max = mb->GetNumberOfBlocks(); cc < max; ++cc)
        {
          const char* name = mb->GetMetaData(cc)->Get(vtkCompositeDataSet::NAME());
          vtkTable* subblock = vtkTable::SafeDownCast(mb->GetBlock(cc));
          if (name && subblock)
          {
            collection[name][rank] = subblock;
          }
        }
      }
    }