Template specialisation for flat template TTree writing. More...

#include <JTreeWriter.hh>

Inheritance diagram for JROOT::JTreeWriter< T, true >:

Public Member Functions
	JTreeWriter (const JTreeParameters &parameters)
	Constructor. More...

Int_t	Write (const T &object)
	Data object output equivalent of TTree::Fill(). More...

Private Attributes
std::vector< TBranch * >	branches_

std::vector< Long_t >	offsets_

Detailed Description

template<class T>
class JROOT::JTreeWriter< T, true >

Template specialisation for flat template TTree writing.

Definition at line 101 of file JTreeWriter.hh.

Constructor & Destructor Documentation

template<class T >

JROOT::JTreeWriter< T, true >::JTreeWriter ( const JTreeParameters & parameters )

inline

Constructor.

Parameters

parameters parameters of TTree

Definition at line 109 of file JTreeWriter.hh.

     {
       SetNameTitle(parameters.getTreeName(), parameters.getTreeTitle());
 
       // if more than one branch, check those are the data members of T
 
       TClass* t_class = TClass::GetClass<T>();
 
       if (t_class == nullptr) {
         THROW(JException, "Could not get class " << typeid(T).name());
       }
 
       TIter      next(t_class->GetListOfRealData());
       TRealData* data{nullptr};
       T          object;
 
       auto* base = reinterpret_cast<uint8_t*>(&object);
 
       while ((data = dynamic_cast<TRealData*>(next())) != nullptr) {
 
         if (!JRootClass::is_tobject_member(data->GetName())) {
 
           auto*       member    = data->GetDataMember();
           auto*       address   = reinterpret_cast<uint8_t*>(base + member->GetOffset());
           std::string type_name = data->GetDataMember()->GetTypeName();
 
           if (member->GetArrayDim() > 0) {
             type_name += "[]";
           }
 
           std::string type_code = JRootPrimitiveTypes::getTypeCode(type_name);
 
           if (type_code.empty()) {
             THROW(JException, "unknown type " << type_name);
           }
 
           std::string leaf = data->GetName();
           leaf += "/" + type_code;
           auto branch = Branch(data->GetName(), address, leaf.c_str());
 
           branches_.push_back(branch);
           offsets_ .push_back(member->GetOffset());
         }
       }
     }

Member Function Documentation

template<class T >

Int_t JROOT::JTreeWriter< T, true >::Write ( const T & object )

inline

Data object output equivalent of TTree::Fill().

Parameters

object data object

Returns: as TTree::Fill

Definition at line 161 of file JTreeWriter.hh.

     {
       auto* base = const_cast<uint8_t*>(reinterpret_cast<const uint8_t*>(&object));
 
       for (size_t i = 0; i < branches_.size(); i++) {
         branches_[i]->SetAddress(reinterpret_cast<uint8_t*>(base + offsets_[i]));
       }
 
       return this->Fill();
     }