Method Generate

cpp/src/arrow/testing/generator.h:332–344

    StepGenerator(T start, T step) : start_(start), step_(step) {}

    Result<std::shared_ptr<Array>> Generate(int64_t num_rows) override {
      TypedBufferBuilder<T> builder;
      ARROW_RETURN_NOT_OK(builder.Reserve(num_rows));
      T val = start_;
      for (int64_t i = 0; i < num_rows; i++) {
        builder.UnsafeAppend(val);
        val += step_;
      }
      start_ = val;
      ARROW_ASSIGN_OR_RAISE(auto buf, builder.Finish());
      return MakeArray(ArrayData::Make(TypeTraits<ArrowType>::type_singleton(), num_rows,
                                       {NULLPTR, std::move(buf)}, /*null_count=*/0));
    }

    std::shared_ptr<DataType> type() const override {
      return TypeTraits<ArrowType>::type_singleton();