EventFileReader.hh

//
// This file is part of MARLEY (Model of Argon Reaction Low Energy Yields)
//
// MARLEY is free software: you can redistribute it and/or modify it under the
// terms of version 3 of the GNU General Public License as published by the
// Free Software Foundation.
//
// For the full text of the license please see COPYING or
// visit http://opensource.org/licenses/GPL-3.0
//
// Please respect the MCnet academic usage guidelines. See GUIDELINES
// or visit https://www.montecarlonet.org/GUIDELINES for details.
 
#pragma once
 
// Standard library includes
#include <fstream>
#include <memory>
#include <string>
 
// MARLEY includes
#include "marley/OutputFile.hh"
 
#ifdef USE_ROOT
// HepMC3 includes
#include "HepMC3/Data/GenEventData.h"
#include "HepMC3/Data/GenRunInfoData.h"
#include "HepMC3/GenRunInfo.h"
 
// ROOT includes
#include "TFile.h"
#include "TTree.h"
#endif
 
// Forward-declare some HepMC3 classes
namespace HepMC3 {
  class GenEvent;
  class GenRunInfo;
  class ReaderAscii;
}
 
namespace marley {

  class EventFileReader {
 
    public:
 
      EventFileReader( const std::string& file_name );
 
      virtual ~EventFileReader() = default;

      virtual bool next_event( HepMC3::GenEvent& ev );

      double flux_averaged_xsec( bool natural_units = false );

      inline EventFileReader& operator>>( HepMC3::GenEvent& ev ) {
        next_event( ev );
        return *this;
      }

      virtual operator bool() const;
 
    protected:

      std::string file_name_;

      OutputFile::Format format_;

      std::ifstream in_;

      std::shared_ptr< HepMC3::ReaderAscii > reader_;
 
      #ifdef USE_ROOT
      std::unique_ptr< TFile > tfile_;
 
      // @brief Pointer to the TTree containing the MARLEY events to be loaded
      TTree* ttree_ = nullptr;

      long event_num_ = -1;

      std::unique_ptr< HepMC3::GenEventData > temp_event_data_;

      HepMC3::GenEventData* temp_event_data_ptr_ = nullptr;

      HepMC3::GenRunInfoData* temp_run_info_data_ = nullptr;

      std::shared_ptr< HepMC3::GenRunInfo > run_info_;
      #endif

      double flux_avg_tot_xs_ = 0.;

      bool initialized_ = false;

      virtual bool deduce_file_format();

      virtual void initialize();

      void ensure_initialized();

      void get_flux_averaged_xsec( const HepMC3::GenRunInfo& run_info );
  };
 
}