TTreeReaderGenerator.h

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// @(#)root/treeplayer:$Id$
// Author: Akos Hajdu 22/06/2015
 
/*************************************************************************
 * Copyright (C) 1995-2015, Rene Brun and Fons Rademakers and al.        *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/
 
#ifndef ROOT_TTreeReaderGenerator
#define ROOT_TTreeReaderGenerator
 
//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TTreeReaderGenerator                                                 //
//                                                                      //
// Generate a Selector using the TTreeReader interface                  //
// (TTreeReaderValue, TTreeReaderArray) to access the data in the tree. //
//                                                                      //
//////////////////////////////////////////////////////////////////////////
 
#include "TTreeGeneratorBase.h"
 
#include "TNamed.h"
#include <vector>
 
class TBranch;
class TBranchElement;
class TLeaf;
 
namespace ROOT {
namespace Internal {
 
   /// 0 for the general case, 1 when this a split clases inside a TClonesArray,
   /// 2 when this is a split classes inside an STL container.
   enum ELocation { kOut=0, kClones, kSTL };
 
   class TTreeReaderDescriptor : public TObject {
   public:
      enum ReaderType { kValue, kArray };
      ReaderType fType;    ///< Type of the reader: Value or Array
      TString fDataType;   ///< Data type of reader
      TString fName;       ///< Reader name
      TString fBranchName; ///< Branch corresponding to the reader
 
      TTreeReaderDescriptor(ReaderType type, TString dataType, TString name, TString branchName) :
         fType(type),
         fDataType(dataType),
         fName(name),
         fBranchName(branchName) { }
   };
 
   class TBranchDescriptor : public TNamed {
   public:
      ELocation             fIsClones;       ///< Type of container
      TString               fContainerName;  ///< Name of the container
      TString               fBranchName;     ///< Name of the branch
      TString               fSubBranchPrefix;///< Prefix (e.g. if the branch name is "A." the prefix is "A"
      TVirtualStreamerInfo *fInfo;           ///< Streamer info
      TBranchDescriptor    *fParent;         ///< Descriptor of the parent branch (NULL for topmost)
 
      TBranchDescriptor(const char *type, TVirtualStreamerInfo *info,
                        const char *branchname, const char *subBranchPrefix, ELocation isclones,
                        const TString &containerName, TBranchDescriptor *parent = nullptr) :
         TNamed(type,type),
         fIsClones(isclones),
         fContainerName(containerName),
         fBranchName(branchname),
         fSubBranchPrefix(subBranchPrefix),
         fInfo(info),
         fParent(parent)
         {
            if (fSubBranchPrefix.Length() && fSubBranchPrefix[fSubBranchPrefix.Length() - 1] == '.') {
               fSubBranchPrefix.Remove(fSubBranchPrefix.Length()-1);
            }
         }
 
      bool IsClones() const { return fIsClones == kClones; }
 
      bool IsSTL() const { return fIsClones == kSTL; }
   };
 
   class TTreeReaderGenerator : public TTreeGeneratorBase
   {
      TString               fClassname;         ///< Class name of the selector
      TList                 fListOfReaders;     ///< List of readers
      bool                  fIncludeAllLeaves;  ///< Should all leaves be included
      bool                  fIncludeAllTopmost; ///< Should all topmost branches be included
      std::vector<TString>  fIncludeLeaves;     ///< Branches whose leaves should be included
      std::vector<TString>  fIncludeStruct;     ///< Branches whom should be included
 
      void   AddReader(TTreeReaderDescriptor::ReaderType type, TString dataType, TString name,
                       TString branchName, TBranchDescriptor *parent = nullptr, bool isLeaf = true);
      UInt_t AnalyzeBranches(TBranchDescriptor *desc, TBranchElement *branch, TVirtualStreamerInfo *info);
      UInt_t AnalyzeBranches(TBranchDescriptor *desc, TIter &branches, TVirtualStreamerInfo *info);
      UInt_t AnalyzeOldBranch(TBranch *branch);
      UInt_t AnalyzeOldLeaf(TLeaf *leaf, Int_t nleaves);
      bool   BranchNeedsReader(TString branchName, TBranchDescriptor *parent, bool isLeaf);
 
      void   ParseOptions();
      void   AnalyzeTree(TTree *tree);
      void   WriteSelector();
 
   public:
      TTreeReaderGenerator(TTree* tree, const char *classname, Option_t *option);
   };
}
}
 
#endif