!6307 Conversion to and from TensorRow in C++

Merge pull request !6307 from MahdiRahmaniHanzaki/c_func

mindspore/ccsrc/minddata/dataset/core/tensor_row.h

@@ -72,6 +72,99 @@ class TensorRow {
   // Destructor
   ~TensorRow() = default;
 
+  /// Convert a vector of primitive types to a TensorRow consisting of n single data Tensors.
+  /// \tparam `T`
+  /// \param[in] o input vector
+  /// \param[out] output TensorRow
+  template <typename T>
+  static Status ConvertToTensorRow(const std::vector<T> &o, TensorRow *output) {
+    DataType data_type = DataType::FromCType<T>();
+    if (data_type == DataType::DE_UNKNOWN) {
+      RETURN_STATUS_UNEXPECTED("ConvertToTensorRow: Data type was not recognized.");
+    }
+    if (data_type == DataType::DE_STRING) {
+      RETURN_STATUS_UNEXPECTED("ConvertToTensorRow: Data type string is not supported.");
+    }
+
+    for (int i = 0; i < o.size(); i++) {
+      std::shared_ptr<Tensor> tensor;
+      Tensor::CreateEmpty(TensorShape({1}), data_type, &tensor);
+      std::string_view s;
+      tensor->SetItemAt({0}, o[i]);
+      output->push_back(tensor);
+    }
+    return Status::OK();
+  }
+
+  /// Convert a single primitive type to a TensorRow consisting of one single data Tensor.
+  /// \tparam `T`
+  /// \param[in] o input
+  /// \param[out] output TensorRow
+  template <typename T>
+  static Status ConvertToTensorRow(const T &o, TensorRow *output) {
+    DataType data_type = DataType::FromCType<T>();
+    if (data_type == DataType::DE_UNKNOWN) {
+      RETURN_STATUS_UNEXPECTED("ConvertToTensorRow: Data type was not recognized.");
+    }
+    if (data_type == DataType::DE_STRING) {
+      RETURN_STATUS_UNEXPECTED("ConvertToTensorRow: Data type string is not supported.");
+    }
+    std::shared_ptr<Tensor> tensor;
+    Tensor::CreateEmpty(TensorShape({1}), data_type, &tensor);
+    tensor->SetItemAt({0}, o);
+    output->push_back(tensor);
+    return Status::OK();
+  }
+
+  /// Return the value in a TensorRow consiting of 1 single data Tensor
+  /// \tparam `T`
+  /// \param[in] input TensorRow
+  /// \param[out] o the primitive variable
+  template <typename T>
+  static Status ConvertFromTensorRow(const TensorRow &input, T *o) {
+    DataType data_type = DataType::FromCType<T>();
+    if (data_type == DataType::DE_UNKNOWN) {
+      RETURN_STATUS_UNEXPECTED("ConvertFromTensorRow: Data type was not recognized.");
+    }
+    if (data_type == DataType::DE_STRING) {
+      RETURN_STATUS_UNEXPECTED("ConvertToTensorRow: Data type string is not supported.");
+    }
+    if (input.size() != 1) {
+      RETURN_STATUS_UNEXPECTED("ConvertFromTensorRow: The input TensorRow is empty.");
+    }
+    if (input.at(0)->type() != data_type) {
+      RETURN_STATUS_UNEXPECTED("ConvertFromTensorRow: The output type doesn't match the input tensor type.");
+    }
+    if (input.at(0)->shape() != TensorShape({1})) {
+      RETURN_STATUS_UNEXPECTED("ConvertFromTensorRow: The input tensors must have a shape of {1}.");
+    }
+    return input.at(0)->GetItemAt(o, {0});
+  }
+
+  /// Convert a TensorRow consisting of n single data tensors to a vector of size n
+  /// \tparam `T`
+  /// \param[in] o TensorRow consisting of n single data tensors
+  /// \param[out] o vector of primitive variable
+  template <typename T>
+  static Status ConvertFromTensorRow(const TensorRow &input, std::vector<T> *o) {
+    DataType data_type = DataType::FromCType<T>();
+    if (data_type == DataType::DE_UNKNOWN) {
+      RETURN_STATUS_UNEXPECTED("ConvertFromTensorRow: Data type was not recognized.");
+    }
+    if (data_type == DataType::DE_STRING) {
+      RETURN_STATUS_UNEXPECTED("ConvertToTensorRow: Data type string is not supported.");
+    }
+    for (int i = 0; i < input.size(); i++) {
+      if (input.at(i)->shape() != TensorShape({1})) {
+        RETURN_STATUS_UNEXPECTED("ConvertFromTensorRow: The input tensor must have a shape of 1.");
+      }
+      T item;
+      RETURN_IF_NOT_OK(input.at(i)->GetItemAt(&item, {0}));
+      o->push_back(item);
+    }
+    return Status::OK();
+  }
+
   // Functions to fetch/set id/vector
   row_id_type getId() const { return id_; }
 

tests/ut/cpp/dataset/CMakeLists.txt

@@ -71,6 +71,7 @@ SET(DE_UT_SRCS
         status_test.cc
         task_manager_test.cc
         tensor_test.cc
+        tensor_row_test.cc
         tensor_string_test.cc
         tensorshape_test.cc
         tfReader_op_test.cc