RootChain.cxx

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// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
// All rights not expressly granted are reserved.
//
// This software is distributed under the terms of the GNU General Public
// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
//
// In applying this license CERN does not waive the privileges and immunities
// granted to it by virtue of its status as an Intergovernmental Organization
// or submit itself to any jurisdiction.
 
 
#include "CommonUtils/RootChain.h"
#include <TString.h>
#include <fairlogger/Logger.h>
#include <fstream>
 
using namespace o2::utils;
 
std::unique_ptr<TChain> RootChain::load(const std::string trName, const std::string inpFile)
{
  // create chain from the single root file or list of files
  std::unique_ptr<TChain> chain;
  if (trName.empty() || inpFile.empty()) {
    LOG(error) << "Tree name or input file is not provided";
    return chain;
  }
  chain = std::make_unique<TChain>(trName.data());
  addFile(chain.get(), inpFile);
  LOG(info) << "Created chain " << chain->GetName() << " with " << chain->GetEntries()
            << " from " << inpFile;
  return chain;
}
 
void RootChain::addFile(TChain* ch, const std::string inp)
{
  // add root file or files from the list extracted from the inp text file
  TString inpS = inp.data();
  if (inpS.EndsWith(".root")) {
    LOG(info) << "Adding " << inp;
    ch->AddFile(inp.data());
  } else {
    std::ifstream inpF(inpS.Data());
    if (!inpF.good()) {
      LOG(error) << "Failed to open input file " << inp << " as a text one";
      return;
    }
    //
    inpS.ReadLine(inpF);
    while (!inpS.IsNull()) {
      inpS = inpS.Strip(TString::kBoth, ' ');
      if (inpS.BeginsWith("//") || inpS.BeginsWith("#")) {
        inpS.ReadLine(inpF);
        continue;
      }
      inpS = inpS.Strip(TString::kBoth, ',');
      inpS = inpS.Strip(TString::kBoth, '"');
      addFile(ch, inpS.Data());
      inpS.ReadLine(inpF);
    }
  }
}