Method ToArrayData

cpp/src/arrow/array/data.cc:643–681

int ArraySpan::num_buffers() const { return GetNumBuffers(*this->type); }

std::shared_ptr<ArrayData> ArraySpan::ToArrayData() const {
  auto result = std::make_shared<ArrayData>(this->type->GetSharedPtr(), this->length,
                                            this->null_count, this->offset);

  for (int i = 0; i < this->num_buffers(); ++i) {
    result->buffers.emplace_back(this->GetBuffer(i));
  }

  Type::type type_id = this->type->id();
  if (type_id == Type::EXTENSION) {
    const ExtensionType* ext_type = checked_cast<const ExtensionType*>(this->type);
    type_id = ext_type->storage_type()->id();
  }

  if (HasVariadicBuffers()) {
    DCHECK_EQ(result->buffers.size(), 3);
    result->buffers.pop_back();
    for (const auto& data_buffer : GetVariadicBuffers()) {
      result->buffers.push_back(data_buffer);
    }
  }

  if (type_id == Type::NA) {
    result->null_count = this->length;
  } else if (this->buffers[0].data == nullptr) {
    // No validity bitmap, so the null count is 0
    result->null_count = 0;
  }

  if (type_id == Type::DICTIONARY) {
    result->dictionary = this->dictionary().ToArrayData();
  } else {
    // Emit children, too
    for (size_t i = 0; i < this->child_data.size(); ++i) {
      result->child_data.push_back(this->child_data[i].ToArrayData());
    }
  }
  return result;
}

std::span<const std::shared_ptr<Buffer>> ArraySpan::GetVariadicBuffers() const {
  DCHECK(HasVariadicBuffers());