[tmva][sofie] Add Indentity operator

Author: lmoneta

tmva/sofie/inc/TMVA/ROperator_Identity.hxx

@@ -0,0 +1,71 @@
+#ifndef TMVA_SOFIE_ROPERATOR_IDENTITY
+#define TMVA_SOFIE_ROPERATOR_IDENTITY
+
+#include "TMVA/SOFIE_common.hxx"
+#include "TMVA/ROperator.hxx"
+#include "TMVA/RModel.hxx"
+
+#include <sstream>
+
+namespace TMVA{
+namespace Experimental{
+namespace SOFIE{
+
+template <typename T>
+class ROperator_Identity final : public ROperator
+{
+
+private:
+
+   std::string fNX;
+   std::string fNY;
+   std::vector<size_t> fShape;
+
+public:
+   ROperator_Identity(){}
+   ROperator_Identity(std::string nameX, std::string nameY):
+      fNX(UTILITY::Clean_name(nameX)), fNY(UTILITY::Clean_name(nameY)){}
+
+   std::vector<ETensorType> TypeInference(std::vector<ETensorType> input){
+      return input;
+   }
+
+   std::vector<std::vector<size_t>> ShapeInference(std::vector<std::vector<size_t>> input){
+      auto ret = input; //suggest copy to compiler
+      return ret;
+   }
+
+   void Initialize(RModel& model){
+       //input must be a graph input, or already initialized intermediate tensor
+      if (model.CheckIfTensorAlreadyExist(fNX) == false){
+        throw std::runtime_error("TMVA SOFIE Identity Op Input Tensor is not found in model");
+      }
+      fShape = model.GetTensorShape(fNX);
+      model.AddIntermediateTensor(fNY, model.GetTensorType(fNX), fShape);
+   }
+
+
+   std::string Generate(std::string OpName){
+      OpName = "op_" + OpName;
+      if (fShape.empty()) {
+         throw std::runtime_error("TMVA SOFIE Transpose Identity called to Generate without being initialized first");
+      }
+      std::stringstream out;
+      int length = 1;
+      for(auto& i: fShape){
+         length *= i;
+      }
+      out << "\n//------ IDENTITY\n";
+      // just copy the tensor pointers
+      out << SP << SP << "tensor_" << fNY << " = tensor_" << fNX << ";\n";
+      return out.str();
+   }
+
+};
+
+}//SOFIE
+}//Experimental
+}//TMVA
+
+
+#endif //TMVA_SOFIE_ROPERATOR_IDENTITY