/// \file
 /// \ingroup tutorial_multicore
 /// \notebook
 /// Demonstrate how to activate and use the implicit parallelisation of TTree::GetEntry.
 /// Such parallelisation creates one task per top-level branch of the tree being read.
 /// In this example, most of the branches are floating point numbers, which are very fast to read.
 ///  This parallelisation can be used, though, on bigger trees with many (complex) branches, which
 ///  are more likely to benefit from speedup gains.
 ///
 /// \macro_code
 ///
 /// \date 26/09/2016
 /// \author Enric Tejedor
 
#include <stdio.h>
#include <stdlib.h>

#include <dirent.h>
#include <iostream>
#include <fstream>
#include <stdint.h>
#include <stdio.h>
#include <string>
#include <math.h>
#include <time.h>
#include <thread>
#include <sys/time.h>

#include "TCut.h"
#include "TEventList.h"
#include <TFile.h>
#include <TROOT.h>
#include <TSystem.h>
#include <TTree.h>
#include <TTreeFormula.h>

 int main(void)
 {
     Long64_t i ;
     TCut pCut ;
    // First enable implicit multi-threading globally, so that the implicit parallelisation is on.
   // The parameter of the call specifies the number of threads to use.
   ROOT::EnableImplicitMT(0);

   // Open the file containing the tree
   //TFile *file = TFile::Open("http://root.cern.ch/files/h1/dstarmb.root");
   TFile *file = TFile::Open("Loc_210506_100k.root");  // 350 MB Large File 
   //TTreeFormula::SetMaxima(10000, 10000, 10000) ;  // with or without

   // Get the tree
   TTree *tree = nullptr;
   file->GetObject<TTree>("dbT", tree);
   //tree->Print() ; 
   // ==> Multithread 
   //pCut = "(dbMinute==935) ||(dbMinute==940) ||(dbMinute==945) ||(dbMinute==950)"; 
   // ==> Single-thread 
   //pCut = "(dbMinute==935 && abs(dbLong-8.638614)<=0.000021 )";    
   // ==> Single-thread 
   pCut = "(dbMinute==935 && abs(dbLong-8.638614)<=0.000021 && abs(dbLat-49.857365)<=0.000013)||(dbMinute==940 && abs(dbLong-8.639461)<=0.000021 && abs(dbLat-49.858223)<=0.000013)" ;
 
     
   gROOT->cd();
   printf("\n tree->CopyTree  START \n") ;
   TTree *stree = nullptr;
   stree = tree->CopyTree(pCut) ;
   printf(" tree->CopyTree  END\n") ;
     
   // Read the branches in parallel.
   // Note that the interface does not change, the parallelisation is internal
   printf(" stree->GetEntry %lld START\n", stree->GetEntries()) ;
   for (i = 0; i < stree->GetEntries(); ++i) //
   {
      stree->GetEntry(i);  // parallel read
   }
   printf(" stree->GetEntry  END\n") ;
    
  
   return 0 ;
 }