#include "TTree.h"
#include "TFile.h"

// Big class with a single instance
class Identical {
public:

  Identical() {
    for (int i = 1; i < 1000; i++) {
      intArray[i] = 1 + intArray[i - 1];
      floatArray[i] = 1 + floatArray[i - 1] * 2;
      doubleArray[i] = 1 - doubleArray[i - 1] * 2;
    }
  }

  Int_t intArray[1000];
  Float_t floatArray[1000];
  Double_t doubleArray[1000];
  ClassDef(Identical, 1);
};
ClassImp(Identical);


class Event {
public:
  Identical *identical;
  Int_t property;
  ClassDef(Event, 1);
};
ClassImp(Event);

// Same as Event, but with transient Identical pointer
class EventTransient {
public:
  Identical *identical; //!
  Int_t property;
  ClassDef(EventTransient, 1);
};
ClassImp(EventTransient);




void TestIdenticalCompr() {

  Identical *id = new Identical;

  // Create a file using auto compression
  Event *ev = new Event;
  ev->identical = id;
  TFile *file = TFile::Open("AutoCompression.root", "RECREATE");
  TTree *tree = new TTree("tree", "");
  tree->Branch("branch", &ev);

  for (int i = 0; i < 1000; i++) {
    ev->property = i;
    tree->Fill();
  }
  tree->Write();
  file->Close();
  delete file;
  delete ev;

  // Create a file using the EventTransient class
  EventTransient *evTransient = new EventTransient;
  evTransient->identical = id;
  file = TFile::Open("Transient.root", "RECREATE");
  tree = new TTree("tree", "");
  tree->Branch("branch", &evTransient);
  TTree *idTree = new TTree("idTree", ""); // tree to store the single identical object
  idTree->Branch("idBranch", &id);
  for (int i = 0; i < 1000; i++) {
    evTransient->property = i;
    tree->Fill();
  }
  idTree->Fill();
  tree->Write();
  idTree->Write();
  file->Close();
  delete file;
  delete evTransient;

  delete id;
}