HepMC3Importer.cpp

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/*
 *  CepGen: a central exclusive processes event generator
 *  Copyright (C) 2024  Laurent Forthomme
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#include <HepMC3/GenEvent.h>
#include <HepMC3/Print.h>
#include <HepMC3/ReaderAscii.h>
#include <HepMC3/ReaderHEPEVT.h>
#include <HepMC3/Version.h>
 
#include <memory>
 
#include "CepGen/Core/Exception.h"
#include "CepGen/EventFilter/EventImporter.h"
#include "CepGen/Modules/EventImporterFactory.h"
#include "CepGenAddOns/HepMC3Wrapper/HepMC3EventInterface.h"
 
namespace cepgen {
  template <typename T>
  class HepMC3Importer final : public EventImporter {
  public:
    explicit HepMC3Importer(const ParametersList& params)
        : EventImporter(params), reader_(new T(steer<std::string>("filename"))) {
      if (!reader_)
        throw CG_FATAL("HepMC3Importer") << "Failed to initialise HepMC reader.";
      CG_INFO("HepMC3Importer") << "Interfacing module initialised "
                                << "for HepMC version " << HEPMC3_VERSION << " and HepMC ASCII file '"
                                << steer<std::string>("filename") << "'.";
    }
 
    bool operator>>(Event& evt) override {
      HepMC3::GenEvent event;
      if (!reader_->read_event(event))
        return false;
      if (!cross_section_retrieved_) {
        if (const auto xsec = event.cross_section(); xsec)
          setCrossSection(Value{xsec->xsec(), xsec->xsec_err()});
        cross_section_retrieved_ = true;
      }
      CG_DEBUG("HepMC3Importer").log([&event](auto& log) { HepMC3::Print::content(log.stream(), event); });
      evt = Event(static_cast<const HepMC3::CepGenEvent&>(event));
      return true;
    }
 
    static ParametersDescription description() {
      auto desc = EventImporter::description();
      desc.setDescription("HepMC3 ASCII file importer module");
      desc.add<std::string>("filename", "input.hepmc").setDescription("Input filename");
      return desc;
    }
 
  private:
    void initialise() override {}
    const std::unique_ptr<T> reader_;
    bool cross_section_retrieved_{false};
  };
}  // namespace cepgen
typedef cepgen::HepMC3Importer<HepMC3::ReaderAscii> HepMC3ImporterASCII;
typedef cepgen::HepMC3Importer<HepMC3::ReaderHEPEVT> HepMC3ImporterHEPEVT;
REGISTER_EVENT_IMPORTER("hepmc", HepMC3ImporterASCII);
//REGISTER_EVENT_IMPORTER("hepevt", HepMC3ImporterHEPEVT); // HEPEVT input is still very shaky, disabling it by default
#if HEPMC3_VERSION_CODE >= 3001000
#include <HepMC3/ReaderAsciiHepMC2.h>
typedef cepgen::HepMC3Importer<HepMC3::ReaderAsciiHepMC2> HepMC3ImporterHepMC2;
REGISTER_EVENT_IMPORTER("hepmc3_hepmc2", HepMC3ImporterHepMC2);
/*#if HEPMC3_VERSION_CODE >= 3002005 && HEPMC3_USE_COMPRESSION
#include <HepMC3/ReaderGZ.h>
typedef cepgen::HepMC3Importer<HepMC3::ReaderGZ<HepMC3::ReaderAscii> > HepMC3ImporterAsciiZ;
typedef cepgen::HepMC3Importer<HepMC3::ReaderGZ<HepMC3::ReaderHEPEVT> > HepMC3ImporterHEPEVTZ;
REGISTER_EVENT_IMPORTER("hepmc_z", HepMC3ImporterAsciiZ);
REGISTER_EVENT_IMPORTER("hepevt_z", HepMC3ImporterHEPEVTZ);
#endif*/
#endif
 
/*#ifdef HEPMC3_ROOTIO
#include <HepMC3/ReaderRoot.h>
#include <HepMC3/ReaderRootTree.h>
typedef cepgen::HepMC3Importer<HepMC3::ReaderRoot> HepMC3ImporterRoot;
typedef cepgen::HepMC3Importer<HepMC3::ReaderRootTree> HepMC3ImporterRootTree;
REGISTER_EVENT_IMPORTER("hepmc_root", HepMC3ImporterRoot);
REGISTER_EVENT_IMPORTER("hepmc_root_tree", HepMC3ImporterRootTree);
#endif*/
 
#ifdef HEPMC3_EXTRA_PLUGINS
#include <ConvertExample/include/ReaderDOT.h>
#include <ConvertExample/include/ReaderRootTreeOPAL.h>
typedef cepgen::HepMC3Importer<HepMC3::ReaderDOT> HepMC3ImporterDOT;
typedef cepgen::HepMC3Importer<HepMC3::ReaderRootTreeOPAL> HepMC3ImporterRootTreeOPAL;
REGISTER_EVENT_IMPORTER("hepmc_dot", HepMC3ImporterDOT);
REGISTER_EVENT_IMPORTER("hepmc_root_tree_opal", HepMC3ImporterRootTreeOPAL);
#endif