Method Finalize

cpp/src/arrow/compute/kernels/hash_aggregate.cc:2164–2176

  }

  Result<Datum> Finalize() override {
    std::unique_ptr<ArrayBuilder> builder;
    RETURN_NOT_OK(MakeBuilder(ctx_->memory_pool(), list(null()), &builder));
    auto list_builder = checked_cast<ListBuilder*>(builder.get());
    auto value_builder = checked_cast<NullBuilder*>(list_builder->value_builder());
    const int64_t* counts = counts_.data();

    for (int64_t group = 0; group < num_groups_; ++group) {
      RETURN_NOT_OK(list_builder->Append(true));
      RETURN_NOT_OK(value_builder->AppendNulls(counts[group]));
    }
    return list_builder->Finish();
  }

  std::shared_ptr<DataType> out_type() const override { return list(null()); }