HepMCReader.h

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
#pragma once
 
#include <framework/core/FrameworkExceptions.h>
#include <mdst/dataobjects/MCParticleGraph.h>
 
#include <string>
#include <fstream>
 
#include "HepMC/GenEvent.h"
 
namespace Belle2 {
  class HepMCReader {
 
  public:
 
    //Define exceptions
    BELLE2_DEFINE_EXCEPTION(HepMCCouldNotOpenFileError, "Could not open file %1% !");
    BELLE2_DEFINE_EXCEPTION(HepMCInvalidDaughterIndicesError,
                            "Event %1%: Invalid daughter indices d1=%2%, d2=%3%, N=%4% (0<=d1<=d2<=N required)");
    BELLE2_DEFINE_EXCEPTION(HepMCHeaderNotValidError, "Event %1%: Event header not understood: %2%");
    BELLE2_DEFINE_EXCEPTION(HepMCConvertFieldError, "Event %1%: Could not convert field %2%: %3%");
    BELLE2_DEFINE_EXCEPTION(HepMCParticleFormatError, "Event %1%: Particle format not understood, got %2% fields !");
    BELLE2_DEFINE_EXCEPTION(HepMCInvalidEventError, "Event is invalid.");
    BELLE2_DEFINE_EXCEPTION(HepMCEmptyEventError,
                            "Event %1%: Number of particles in event is %2% ! (This could mean EOF is reached.) ");
    HepMCReader(const int minEvent = 0, const int maxEvent = INT_MAX): m_nVirtual(0), m_wrongSignPz(false), m_minEvent(minEvent),
      m_maxEvent(maxEvent) {}
 
    ~HepMCReader() { if (m_input) {m_input.close();} }
 
    void open(const std::string& filename);
 
    void closeCurrentInputFile() {m_input.close();}
 
    int nextValidEvent(HepMC::GenEvent& evt);
    int getEvent(MCParticleGraph& graph, double& weight);
 
    int m_nVirtual;        
    bool m_wrongSignPz;    
    const int m_minEvent; 
    const int m_maxEvent; 
    int countEvents(const std::string& filename); 
  protected:
 
    void readNextEvent(HepMC::GenEvent& evt); 
    std::ifstream m_input; 
  };
 
}