source: git/external/ExRootAnalysis/ExRootTreeBranch.cc@ 3b02069

/** \class ExRootTreeBranch
 *
 *  Class handling object creation
 *  It is also used for output ROOT tree branches
 *
 *  \author P. Demin - UCL, Louvain-la-Neuve
 *
 */

#include "ExRootAnalysis/ExRootTreeBranch.h"

#include "TClonesArray.h"
#include "TFile.h"
#include "TString.h"
#include "TTree.h"

#include <iostream>
#include <sstream>
#include <stdexcept>

using namespace std;

//------------------------------------------------------------------------------

ExRootTreeBranch::ExRootTreeBranch(const char *name, TClass *cl, TTree *tree) :
  fSize(0), fCapacity(1), fData(0)
{
  stringstream message;
  //  cl->IgnoreTObjectStreamer();
  //  cl->BypassStreamer();
  fData = new TClonesArray(cl, fCapacity);

  if(fData)
  {
    fData->SetName(name);
    fData->ExpandCreateFast(fCapacity);
    fData->Clear();
    if(tree)
    {
      tree->Branch(name, &fData, 64000);
      tree->Branch(TString(name) + "_size", &fSize, TString(name) + "_size/I");
    }
  }
  else
  {
    message << "can't create TClonesArray for branch '" << name << "'";
    throw runtime_error(message.str());
  }
}

//------------------------------------------------------------------------------

ExRootTreeBranch::~ExRootTreeBranch()
{
  if(fData) delete fData;
}

//------------------------------------------------------------------------------

TObject *ExRootTreeBranch::NewEntry()
{
  if(!fData) return 0;

  if(fSize >= fCapacity)
  {
    if(fCapacity < 10)
      fCapacity = 10;
    else if(fCapacity < 30)
      fCapacity = 30;
    else if(fCapacity < 100)
      fCapacity = 100;
    else if(fCapacity < 250)
      fCapacity = 250;
    else
      fCapacity *= 2;

    fData->ExpandCreateFast(fCapacity);

    fData->Clear();
    fData->ExpandCreateFast(fSize);
  }

  return fData->AddrAt(fSize++);
}

//------------------------------------------------------------------------------

void ExRootTreeBranch::Clear()
{
  fSize = 0;
  if(fData) fData->Clear();
}

//------------------------------------------------------------------------------