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// @(#)root/tree:$Id: TTreeCloner.h 29413 2009-07-09 14:10:29Z pcanal $
// Author: Philippe Canal 07/11/2005

 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *

#ifndef ROOT_TTreeCloner
#define ROOT_TTreeCloner

//                                                                      //
// TTreeCloner                                                          //
//                                                                      //
// Class implementing or helping  the various TTree cloning method      //
//                                                                      //

#ifndef ROOT_TObjArray
#include "TObjArray.h"

#include <vector>

#ifdef R__OLDHPACC
namespace std {
   using ::string;
   using ::vector;

class TBranch;
class TTree;

class TTreeCloner {
   TString    fWarningMsg;       //Text of the error message lead to an 'invalid' state

   Bool_t     fIsValid;
   Bool_t     fNeedConversion;   //True if the fast merge is not possible but a slow merge might possible.
   UInt_t     fOptions;
   TTree     *fFromTree;
   TTree     *fToTree;
   Option_t  *fMethod;
   TObjArray  fFromBranches;
   TObjArray  fToBranches;

   UInt_t     fMaxBaskets;
   UInt_t    *fBasketBranchNum;  //[fMaxBaskets] Index of the branch(es) of the basket.
   UInt_t    *fBasketNum;        //[fMaxBaskets] index of the basket within the branch.

   Long64_t  *fBasketSeek;       //[fMaxBaskets] list of basket position to be read.
   Long64_t  *fBasketEntry;      //[fMaxBaskets] list of basket start entries.
   UInt_t    *fBasketIndex;      //[fMaxBaskets] ordered list of basket indices to be written.

   UShort_t   fPidOffset;        //Offset to be added to the copied key/basket.

   UInt_t     fCloneMethod;      //Indicates which cloning method was selected.
   Long64_t   fToStartEntries;   //Number of entries in the target tree before any addition.

   enum ECloneMethod {
      kDefault             = 0,
      kSortBasketsByBranch = 1,
      kSortBasketsByOffset = 2,
      kSortBasketsByEntry  = 3

   class CompareSeek {
      TTreeCloner *fObject;
      CompareSeek(TTreeCloner *obj) : fObject(obj) {}
      bool operator()(UInt_t i1, UInt_t i2);

   class CompareEntry {
      TTreeCloner *fObject;
      CompareEntry(TTreeCloner *obj) : fObject(obj) {}
      bool operator()(UInt_t i1, UInt_t i2);

   friend class CompareSeek;
   friend class CompareEntry;

   enum EClonerOptions {
      kNone       = 0,
      kNoWarnings = BIT(1)

   TTreeCloner(TTree *from, TTree *to, Option_t *method, UInt_t options = kNone);
   virtual ~TTreeCloner();

   void   CloseOutWriteBaskets();
   UInt_t CollectBranches(TBranch *from, TBranch *to);
   UInt_t CollectBranches(TObjArray *from, TObjArray *to);
   UInt_t CollectBranches();
   void   CollectBaskets();
   void   CopyMemoryBaskets();
   void   CopyStreamerInfos();
   void   CopyProcessIds();
   const char *GetWarning() const { return fWarningMsg; }
   Bool_t Exec();
   Bool_t IsValid() { return fIsValid; }
   Bool_t NeedConversion() { return fNeedConversion; }
   void   SortBaskets();
   void   WriteBaskets();

   ClassDef(TTreeCloner,0); // helper used for the fast cloning of TTrees.