JROOT::JTreeBranchAddresses< T > Class Template Reference

Class responsible to setup TTree branch addresses for reading objects of type T. More...

#include <JTreeBranchAddresses.hh>

Inheritance diagram for JROOT::JTreeBranchAddresses< T >:

Public Member Functions
void	setBranchAddress (TTree &tree)
void	release ()
	Release memory.
T *	getAddress () const
	Get address.

Protected Attributes
T *	address

Detailed Description

template<typename T>
class JROOT::JTreeBranchAddresses< T >

Class responsible to setup TTree branch addresses for reading objects of type T.

Definition at line 39 of file JTreeBranchAddresses.hh.

Member Function Documentation

setBranchAddress()

template<typename T >

void JROOT::JTreeBranchAddresses< T >::setBranchAddress ( TTree & tree )

inline

Definition at line 53 of file JTreeBranchAddresses.hh.

  {
    TObjArray* branches = tree.GetListOfBranches();
    // single branch
    if (branches->GetEntries() == 1) {
      tree.SetBranchAddress(branches->First()->GetName(), &this->address);
      return;
    }
 
    // 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());
    }
 
    auto branch_names = to_vector(tree.GetListOfBranches());
    auto all_member_names = to_vector(t_class->GetListOfRealData());
 
    std::vector<std::string> member_names;
 
    // remove TObject specific members
    std::copy_if(all_member_names.begin(), all_member_names.end(), std::back_inserter(member_names),
                 [](const std::string& member_name)
                 { return !JRoot::is_tobject_member(member_name.c_str()); });
 
    std::sort(branch_names.begin(), branch_names.end());
    std::sort(member_names.begin(), member_names.end());
 
    // all members must have a corresponding branch
    // (but more branches are allowed, we just don't handle them here)
    if (std::includes(branch_names.begin(), branch_names.end(), member_names.begin(),
                      member_names.end())) {
 
      this->address = new T;
 
      auto* base = reinterpret_cast<uint8_t*>(this->address);
 
      for (const auto& member_name : member_names) {
        auto* member = static_cast<TDataMember*>(t_class->GetDataMember(member_name.c_str()));
        tree.SetBranchAddress(member_name.c_str(),
                              reinterpret_cast<void*>(base + member->GetOffset()));
      }
      return;
    }
 
    // if we cannot configure the tree, try to give some relevant information
    // to the user who will have to deal with the exception...
    THROW(JException, "Members of type " << typeid(T).name() << "\n"
                                         << JEEP::JEEPZ() << member_names << "\nBranches in tree\n"
                                         << JEEP::JEEPZ() << branch_names);
  }

release()

template<class T >

void JROOT::JRootAddress< T >::release ( )

inlineinherited

Release memory.

Definition at line 54 of file JRootAddress.hh.

    {
      if (address != NULL) {
 
        delete address;
 
        address = NULL;
      }
    }

getAddress()

template<class T >

T * JROOT::JRootAddress< T >::getAddress ( ) const

inlineinherited

Get address.

Returns

address

Definition at line 70 of file JRootAddress.hh.

    {
      return address;
    }

Member Data Documentation

address

template<class T >

T* JROOT::JRootAddress< T >::address

protectedinherited

Definition at line 76 of file JRootAddress.hh.

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The documentation for this class was generated from the following file:

• JTreeBranchAddresses.hh