Method seekToRowGroup

c++/src/Reader.cc:550–571

  }

  void RowReaderImpl::seekToRowGroup(uint32_t rowGroupEntryId) {
    // store positions for selected columns
    std::list<std::list<uint64_t>> positions;
    // store position providers for selected colimns
    std::unordered_map<uint64_t, PositionProvider> positionProviders;

    for (auto rowIndex = rowIndexes_.cbegin(); rowIndex != rowIndexes_.cend(); ++rowIndex) {
      uint64_t colId = rowIndex->first;
      const proto::RowIndexEntry& entry =
          rowIndex->second.entry(static_cast<int32_t>(rowGroupEntryId));

      // copy index positions for a specific column
      positions.push_back({});
      auto& position = positions.back();
      for (int pos = 0; pos != entry.positions_size(); ++pos) {
        position.push_back(entry.positions(pos));
      }
      positionProviders.insert(std::make_pair(colId, PositionProvider(position)));
    }

    reader_->seekToRowGroup(positionProviders);
  }

  const FileContents& RowReaderImpl::getFileContents() const {
    return *contents_;