Method FromTensor

cpp/src/arrow/extension/fixed_shape_tensor.cc:228–314

}

Result<std::shared_ptr<FixedShapeTensorArray>> FixedShapeTensorArray::FromTensor(
    const std::shared_ptr<Tensor>& tensor) {
  auto permutation = internal::ArgSort(tensor->strides(), std::greater<>());
  if (permutation[0] != 0) {
    return Status::Invalid(
        "Only first-major tensors can be zero-copy converted to arrays");
  }
  permutation.erase(permutation.begin());

  std::vector<int64_t> cell_shape;
  cell_shape.reserve(permutation.size());
  for (auto i : permutation) {
    cell_shape.emplace_back(tensor->shape()[i]);
  }

  std::vector<std::string> dim_names;
  if (!tensor->dim_names().empty()) {
    dim_names.reserve(permutation.size());
    for (auto i : permutation) {
      dim_names.emplace_back(tensor->dim_names()[i]);
    }
  }

  for (int64_t& i : permutation) {
    --i;
  }

  auto ext_type = internal::checked_pointer_cast<ExtensionType>(
      fixed_shape_tensor(tensor->type(), cell_shape, permutation, dim_names));

  std::shared_ptr<Array> value_array;
  switch (tensor->type_id()) {
    case Type::UINT8: {
      value_array = std::make_shared<UInt8Array>(tensor->size(), tensor->data());
      break;
    }
    case Type::INT8: {
      value_array = std::make_shared<Int8Array>(tensor->size(), tensor->data());
      break;
    }
    case Type::UINT16: {
      value_array = std::make_shared<UInt16Array>(tensor->size(), tensor->data());
      break;
    }
    case Type::INT16: {
      value_array = std::make_shared<Int16Array>(tensor->size(), tensor->data());
      break;
    }
    case Type::UINT32: {
      value_array = std::make_shared<UInt32Array>(tensor->size(), tensor->data());
      break;
    }
    case Type::INT32: {
      value_array = std::make_shared<Int32Array>(tensor->size(), tensor->data());
      break;
    }
    case Type::UINT64: {
      value_array = std::make_shared<UInt64Array>(tensor->size(), tensor->data());