Method Write

cpp/src/parquet/arrow/writer.cc:158–191

Writes out all leaf parquet columns to the RowGroupWriter that this object was constructed with. Each leaf column is written fully before the next column is written (i.e. no buffering is assumed). Columns are written in DFS order.

  //
  // Columns are written in DFS order.
  Status Write(ArrowWriteContext* ctx) {
    for (int leaf_idx = 0; leaf_idx < leaf_count_; leaf_idx++) {
      ColumnWriter* column_writer;
      if (row_group_writer_->buffered()) {
        const int column_index = start_leaf_column_index_ + leaf_idx;
        PARQUET_CATCH_NOT_OK(column_writer = row_group_writer_->column(column_index));
      } else {
        PARQUET_CATCH_NOT_OK(column_writer = row_group_writer_->NextColumn());
      }
      for (auto& level_builder : level_builders_) {
        RETURN_NOT_OK(level_builder->Write(
            leaf_idx, ctx, [&](const MultipathLevelBuilderResult& result) {
              size_t visited_component_size = result.post_list_visited_elements.size();
              DCHECK_GT(visited_component_size, 0);
              if (visited_component_size != 1) {
                return Status::NotImplemented(
                    "Lists with non-zero length null components are not supported");
              }
              const ElementRange& range = result.post_list_visited_elements[0];
              std::shared_ptr<Array> values_array =
                  result.leaf_array->Slice(range.start, range.Size());

              return column_writer->WriteArrow(result.def_levels, result.rep_levels,
                                               result.def_rep_level_count, *values_array,
                                               ctx, result.leaf_is_nullable);
            }));
      }

      if (!row_group_writer_->buffered()) {
        PARQUET_CATCH_NOT_OK(column_writer->Close());
      }
    }
    return Status::OK();
  }

  // Make a new object by converting each chunk in |data| to a MultipathLevelBuilder.
  //