TruthDecoratorAlg.cxx

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/*
  Copyright (C) 2002-2025 CERN for the benefit of the ATLAS collaboration
*/


#include "TruthDecoratorAlg.h"
 

IDTPM::TruthDecoratorAlg::TruthDecoratorAlg(
    const std::string& name,
    ISvcLocator* pSvcLocator ) :
  AthReentrantAlgorithm( name, pSvcLocator ) { }
 

StatusCode IDTPM::TruthDecoratorAlg::initialize() {
 
  ATH_CHECK( m_truthParticlesName.initialize(
                not m_truthParticlesName.key().empty() ) );
 
  ATH_CHECK( m_truthClassifier.retrieve() );

  IDTPM::createDecoratorKeysAndAccessor(
      *this, m_truthParticlesName,
      m_prefix.value(), m_decor_truth_names, m_decor_truth );
 
  if( m_decor_truth.size() != NDecorations ) {
    ATH_MSG_ERROR( "Incorrect booking of truth class decorations" );
    return StatusCode::FAILURE;
  }
 
  return StatusCode::SUCCESS;
}
 

StatusCode IDTPM::TruthDecoratorAlg::execute( const EventContext& ctx ) const {

  SG::ReadHandle< xAOD::TruthParticleContainer > ptruths( m_truthParticlesName, ctx );
  if( not ptruths.isValid() ) {
    ATH_MSG_ERROR( "Failed to retrieve truth particles container" );
    return StatusCode::FAILURE;
  }

  if( IDTPM::decorationsAllExist( *ptruths, m_decor_truth ) ) {
    ATH_MSG_DEBUG( "All decorations already exist. Exiting gracefully" );
    return StatusCode::SUCCESS;
  }

  std::vector< IDTPM::OptionalDecoration<xAOD::TruthParticleContainer, int> >
      truth_decor( IDTPM::createDecoratorsIfNeeded( *ptruths, m_decor_truth, ctx ) );
 
  if( truth_decor.empty() ) {
    ATH_MSG_ERROR( "Failed to book truth class decorations" );
    return StatusCode::FAILURE;
  }
 
  for( const xAOD::TruthParticle* truth : *ptruths ) {
    ATH_CHECK( decorateTruthParticle( *truth, truth_decor ) );
  }
 
  return StatusCode::SUCCESS;
}
 

StatusCode IDTPM::TruthDecoratorAlg::decorateTruthParticle(
                const xAOD::TruthParticle& truth,
                std::vector< IDTPM::OptionalDecoration< xAOD::TruthParticleContainer,
                                                        int>>& truth_decor) const {

  auto truthClass = m_truthClassifier->particleTruthClassifier( &truth );
  int type = static_cast<int>( truthClass.first );
  int origin = static_cast<int>( truthClass.second );

  IDTPM::decorateOrRejectQuietly( truth, truth_decor[Type],   type );
  IDTPM::decorateOrRejectQuietly( truth, truth_decor[Origin], origin );
 
  return StatusCode::SUCCESS;
}