Method WriteMetadata

cpp/src/arrow/ipc/feather.cc:472–507

struct ColumnMetadata {
  flatbuffers::Offset<void> WriteMetadata(FBB& fbb) {  // NOLINT
    switch (this->meta_type) {
      case ColumnType::PRIMITIVE:
        // flatbuffer void
        return 0;
      case ColumnType::CATEGORY: {
        auto cat_meta = fbs::CreateCategoryMetadata(
            fbb, GetPrimitiveArray(fbb, this->category_levels), this->category_ordered);
        return cat_meta.Union();
      }
      case ColumnType::TIMESTAMP: {
        // flatbuffer void
        flatbuffers::Offset<flatbuffers::String> tz = 0;
        if (!this->timezone.empty()) {
          tz = fbb.CreateString(this->timezone);
        }

        auto ts_meta =
            fbs::CreateTimestampMetadata(fbb, ToFlatbufferEnum(this->temporal_unit), tz);
        return ts_meta.Union();
      }
      case ColumnType::DATE: {
        auto date_meta = fbs::CreateDateMetadata(fbb);
        return date_meta.Union();
      }
      case ColumnType::TIME: {
        auto time_meta =
            fbs::CreateTimeMetadata(fbb, ToFlatbufferEnum(this->temporal_unit));
        return time_meta.Union();
      }
      default:
        // null
        DCHECK(false);
        return 0;
    }
  }

  ArrayMetadata values;
  ColumnType::type meta_type;