StdHepFileSource.cc

Go to the documentation of this file.

// -- marlinmt headers
#include <marlinmt/lcio/ReaderListener.h>
#include <marlinmt/DataSourcePlugin.h>
#include <marlinmt/PluginManager.h>
#include <marlinmt/Logging.h>
#include <marlinmt/EventStore.h>
#include <marlinmt/RunHeader.h>
#include <jenkinsHash.h>

// -- lcio headers
#include <IMPL/LCEventImpl.h>
#include <IMPL/LCRunHeaderImpl.h>
#include <UTIL/LCStdHepRdr.h>
#include <UTIL/LCTOOLS.h>

// -- std headers
#include <functional>

using namespace std::placeholders ;

namespace marlinmt {

  class StdHepFileSource : public DataSourcePlugin {
    using FileReader = std::shared_ptr<UTIL::LCStdHepRdr> ;

  public:
    StdHepFileSource() ;
    ~StdHepFileSource() = default ;

    // from DataSourcePlugin
    void initialize() override ;
    bool readOne() override ;

  private:
    StringParameter _fileName {*this, "StdHepFileName",
            "The StdHep input file name" } ;

    IntParameter _maxRecordNumber {*this, "MaxRecordNumber",
            "The maximum number of events to read", 0 } ;

    StringParameter _collectionName {*this, "CollectionName",
            "The name of the MCParticle collection to add in the event", "MCParticle" } ;

    FileReader                  _fileReader {nullptr} ;
    bool                        _isFirstEvent {true} ;
    int                         _currentReadEvents {0} ;
  };

  //--------------------------------------------------------------------------
  //--------------------------------------------------------------------------

  StdHepFileSource::StdHepFileSource() :
    DataSourcePlugin("StdHepReader") {
    setDescription( "Reads StdHep files as input and creates LCIO events with MCParticle collections" ) ;
  }

  //--------------------------------------------------------------------------

  void StdHepFileSource::initialize() {
    DataSourcePlugin::initialize() ;
    // create the file reader
    _fileReader = std::make_shared<FileReader::element_type>( _fileName.get().c_str() ) ;
  }

  //--------------------------------------------------------------------------

  bool StdHepFileSource::readOne() {
    // first call is a run header
    if( _isFirstEvent ) {
      auto rhdr = std::make_shared<RunHeader>() ;
      rhdr->setDescription( " Events read from stdhep input file: " + _fileName.get() ) ;
      rhdr->setRunNumber( 0 ) ;
      processRunHeader( rhdr ) ;
      _isFirstEvent = false ;
      return true ;
    }
    // next calls are events from the stdhep reader
    auto collection = _fileReader->readEvent() ;
    if( nullptr == collection ) {
      return false ;
    }
    if( (_currentReadEvents > 0) and (_currentReadEvents >= _maxRecordNumber) ) {
      delete collection ;
      return false ;
    }
    auto event = std::make_shared<IMPL::LCEventImpl>() ;
    event->setRunNumber( 0 ) ;
    event->setEventNumber( _currentReadEvents ) ;
    event->addCollection( collection, _collectionName ) ;
    auto store = std::make_shared<EventStore>() ;
    store->setEvent( event ) ;
    // generate the event unique id
    auto evtn = event->getEventNumber() ;
    auto runn = event->getRunNumber() ;
    unsigned char * c = (unsigned char *) &evtn ;
    unsigned int uid = jenkins_hash( c, sizeof evtn, 0) ;
    c = (unsigned char *) &runn ;
    uid = jenkins_hash( c, sizeof runn, 0) ;
    store->setUID( uid ) ;
    processEvent( store ) ;
    ++_currentReadEvents ;
    return true ;
  }

  MARLINMT_DECLARE_DATASOURCE_NAME( StdHepFileSource, "StdHepReader" )

}