C++ TBranch::InheritsFrom方法代码示例

void ResetDeleteBranches(TTree* tree) {
    TObjArray* branches = tree->GetListOfBranches();
    Int_t nb = branches->GetEntriesFast();
    for (Int_t i = 0; i < nb; ++i) {
        TBranch* br = (TBranch*) branches->UncheckedAt(i);
        if (br->InheritsFrom(TBranchElement::Class())) {
            ((TBranchElement*) br)->ResetDeleteObject();
        }
    }
}

template <class HolderClass> bool verifyBranch(const char *testname, TTree *chain, const char *bname, int type = 0) {
   static HolderClass *gHolder = new HolderClass;
   HolderClass **add = 0;
   HolderClass *holder = 0;

   TBranch *branch = chain->GetBranch(bname);
   if (branch==0) {
      TestError("treeReading",Form("Missing branch: %s",bname));
      return false;
   }
   
   if (branch->InheritsFrom("TBranchObject")) {
      TLeafObject *tbo = dynamic_cast<TLeafObject*>(branch->GetListOfLeaves()->At(0));
      holder = (HolderClass*)(tbo->GetObject());

      if (holder==0) {
         TestError("treeReading",Form("BranchObject %s with holder == 0!",bname));
         return false;         
      }
   } else {
      add = (HolderClass**)branch->GetAddress();
      if (add==0) {
         TestError("treeReading",Form("Branch %s with add == 0!",bname));
         return false;
      }
      void **p;
      switch (type) {
         case 0: holder = *add; break;
         case 1: p = (void**) &(gHolder->fScalarPtr); *p = ((TBranchElement*)branch)->GetObject(); break;
         case 2: p = (void**) &(gHolder->fObjectPtr); *p = ((TBranchElement*)branch)->GetObject(); break;
         case 3: p = (void**) &(gHolder->fNestedPtr); *p = ((TBranchElement*)branch)->GetObject(); break;
      }
   }
   
   int splitlevel = branch->GetSplitLevel();

   switch (type) {
      case 0: return holder->Verify(chain->GetTree()->GetReadEntry(),Form("%s %s",testname,bname),splitlevel);
      case 1: return gHolder->VerifyScalarPtr(chain->GetTree()->GetReadEntry(),Form("%s %s",testname,bname),splitlevel);
      case 2: return gHolder->VerifyObjectPtr(chain->GetTree()->GetReadEntry(),Form("%s %s",testname,bname),splitlevel);
      case 3: return gHolder->VerifyNestedPtr(chain->GetTree()->GetReadEntry(),Form("%s %s",testname,bname),splitlevel);
      default: 
         TestError("treeReading",Form("Unknown type %d in verifyBranch",type));
         return false;
   }
}

bool dt_RunDrawTest(const char* from, Int_t mode = 0, Int_t verboseLevel = 0) {
  // This launch a test a TTree::Draw.
  // The mode currently available are:
  //    0: Do not load the shared library
  //    1: Load the shared library before opening the file
  //    2: Load the shared library after opening the file
  //    3: Simple TChain test with shared library
  //    4: Simple Friend test with shared library
  // The verboseLeve currently available:
  //    0: As silent as possible, only report errors and overall speed results.
  //    1: Output 0 + label for the start of each phase
  //    2: Output 1 + more details on the different phase being done
  //    3: Output 2 + stop at the first and draw a canvas showing the differences

//gDebug = 5;
   SetVerboseLevel(verboseLevel);

   if (mode == 1) {
      if (!TClassTable::GetDict("Event")) {
         gSystem->Load("Event_cxx");
     }     
      gHasLibrary = kTRUE;
   }

   TFile *hfile = 0;
   TTree *tree = 0;
   if (mode <3) {
      hfile = new TFile(from);
      tree = (TTree*)hfile->Get("T");
   }

   if (mode >= 2 && mode <= 4) {
      if (!TClassTable::GetDict("Event")) {
         gSystem->Load("Event_cxx");
      } else {
         cerr << "Since libEvent.so has already been loaded, mode 2 can not be tested!";
         cerr << endl;
      }
      gHasLibrary = kTRUE;
   }

   if (mode == 3) {
      // Test Chains.
      TChain * chain = new TChain("T");
      chain->Add(from);
      chain->Add(from);
      tree = chain;
   }

   if (mode == 4) {
      // Test friends.
      tree = new TTree("T","Base of friendship");
      tree->AddFriend("T",from);
   }

   TBranch *eb = tree->GetBranch("event");
   gBranchStyle = (int) eb->InheritsFrom(TBranchElement::Class());
   // cerr << "Branch style is " << gBranchStyle << endl;

   if (gQuietLevel<2) cout << "Generating histograms from TTree::Draw" << endl;
   TDirectory* where = GenerateDrawHist(tree,2,gQuietLevel);
 
   if (gQuietLevel<2) cout << "Comparing histograms" << endl;
   if (Compare(where)>0) {
     cout << "DrawTest: Comparison failed" << endl;
     return false;
   }
   DrawMarks();

   if (gQuietLevel<2) cout << "DrawTest: Comparison was successfull" << endl;
   if (hfile) delete hfile;
   else delete tree;
   gROOT->GetList()->Delete();

   return true;
}