SeedingAlg.cxx

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/*
  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
*/
 
#include "src/SeedingAlg.h"
 
// ACTS
#include "Acts/Definitions/Units.hpp"
#include "Acts/MagneticField/MagneticFieldContext.hpp"
#include "ActsGeometry/ATLASMagneticFieldWrapper.h"
#include "Acts/Seeding/BinnedGroup.hpp"
#include "Acts/Seeding/SeedFilter.hpp"
#include "Acts/Seeding/SeedFinder.hpp"
 
#include "InDetReadoutGeometry/SiDetectorElementCollection.h"
#include "TrkSpacePoint/SpacePointCollection.h"
#include "SiSPSeededTrackFinderData/SiSpacePointForSeed.h"
#include "AthenaMonitoringKernel/Monitored.h"
#include "InDetReadoutGeometry/SiDetectorElement.h"
 
 
#include "SiSPSeededTrackFinderData/ITkSiSpacePointForSeed.h"
 
#include "ActsInterop/TableUtils.h"
 
namespace ActsTrk {
  SeedingAlg::SeedingAlg( const std::string &name,
              ISvcLocator *pSvcLocator )
    : AthReentrantAlgorithm( name,pSvcLocator ) 
  {}
  
  StatusCode SeedingAlg::initialize() {
    ATH_MSG_INFO( "Initializing " << name() << " ... " );
    if (m_fastTracking)
      ATH_MSG_INFO( "   using fast tracking configuration.");
    
    // Retrieve seed tool
    ATH_CHECK( m_seedsTool.retrieve() );
 
    // Cond
    ATH_CHECK( m_beamSpotKey.initialize() );
    ATH_CHECK( m_fieldCondObjInputKey.initialize() );
 
    // Read and Write handles
    ATH_CHECK( m_spacePointKey.initialize() );
    ATH_CHECK( m_seedKey.initialize() );
 
    ATH_CHECK( m_monTool.retrieve(EnableTool{not m_monTool.empty()}) );
 
    return StatusCode::SUCCESS;
  }
 
  StatusCode SeedingAlg::finalize() {
     ATH_MSG_INFO("Seed statistics" << std::endl << makeTable(m_stat,
                                                              std::array<std::string, kNStat>{
                                                                 "Spacepoints",
                                                                 "Seeds"
                                                                    }).columnWidth(10));
    return StatusCode::SUCCESS;
  }
 
  StatusCode SeedingAlg::execute(const EventContext& ctx) const {
    ATH_MSG_DEBUG( "Executing " << name() <<" ... " );
 
    auto timer = Monitored::Timer<std::chrono::milliseconds>( "TIME_execute" );
    auto time_seedCreation = Monitored::Timer<std::chrono::milliseconds>( "TIME_seedCreation" );
    auto mon_nSeeds = Monitored::Scalar<int>("nSeeds");
    auto mon = Monitored::Group( m_monTool, timer, time_seedCreation, mon_nSeeds );
 
    // ================================================== // 
    // ===================== OUTPUTS ==================== //
    // ================================================== // 
    
    SG::WriteHandle< ActsTrk::SeedContainer > seedHandle = SG::makeHandle( m_seedKey, ctx );
    ATH_MSG_DEBUG( "    \\__ Seed Container `" << m_seedKey.key() << "` created ..." );
    ATH_CHECK( seedHandle.record( std::make_unique< ActsTrk::SeedContainer >() ) );
    ActsTrk::SeedContainer *seedPtrs = seedHandle.ptr();
    
    // ================================================== //
    // ===================== INPUTS ===================== // 
    // ================================================== //
    
    // Read the Beam Spot information
    SG::ReadCondHandle<InDet::BeamSpotData> beamSpotHandle { m_beamSpotKey, ctx };
    ATH_CHECK( beamSpotHandle.isValid() );
    if (beamSpotHandle.cptr() == nullptr) {
      ATH_MSG_ERROR("Retrieved Beam Spot Handle contains a nullptr");
      return StatusCode::FAILURE;
    }
    auto beamSpotData = beamSpotHandle.cptr();
    // Beam Spot Position
    Acts::Vector3 beamPos( beamSpotData->beamPos().x() * Acts::UnitConstants::mm,
                           beamSpotData->beamPos().y() * Acts::UnitConstants::mm,
                           beamSpotData->beamPos().z() * Acts::UnitConstants::mm);
    
    
    ATH_MSG_DEBUG( "Retrieving elements from " << m_spacePointKey.size() << " input collections...");
    std::vector<const xAOD::SpacePointContainer *> all_input_collections;
    all_input_collections.reserve(m_spacePointKey.size());
    
    std::size_t number_input_space_points = 0;
    for (const auto& spacePointKey : m_spacePointKey) {
      ATH_MSG_DEBUG( "Retrieving from Input Collection '" << spacePointKey.key() << "' ..." );
      SG::ReadHandle< xAOD::SpacePointContainer > handle = SG::makeHandle( spacePointKey, ctx );
      ATH_CHECK( handle.isValid() );
      all_input_collections.push_back(handle.cptr());
      ATH_MSG_DEBUG( "    \\__ " << handle->size() << " elements!");
      number_input_space_points += handle->size();
    }
    
    // Apply selection on which SPs you want to use from the input container
    std::vector<const xAOD::SpacePoint*> selectedSpacePoints;
    selectedSpacePoints.reserve(number_input_space_points);
    
    for (const auto* collection : all_input_collections) {
      selectedSpacePoints.insert(selectedSpacePoints.end(), collection->begin(), collection->end());
    }
    
    ATH_MSG_DEBUG( "    \\__ Total input space points: " << selectedSpacePoints.size());
    m_stat[kNSpacepoints] += selectedSpacePoints.size();
    
    // Early Exit in case no space points at this stage
    if (selectedSpacePoints.empty()) {
      ATH_MSG_DEBUG("No input space points found, we stop seeding");
      return StatusCode::SUCCESS;
    }
    
    // ================================================== //
    // ===================== CONDS ====================== // 
    // ================================================== //
 
    // Read the b-field information
    SG::ReadCondHandle<AtlasFieldCacheCondObj> readHandle { m_fieldCondObjInputKey, ctx };
    ATH_CHECK( readHandle.isValid() );
    
    const AtlasFieldCacheCondObj* fieldCondObj{ *readHandle };
    if (fieldCondObj == nullptr) {
      ATH_MSG_ERROR("Failed to retrieve AtlasFieldCacheCondObj with key " << m_fieldCondObjInputKey.key());
      return StatusCode::FAILURE;
    }
    
    // Get the magnetic field
    // Using ACTS classes in order to be sure we are consistent
    Acts::MagneticFieldContext magFieldContext(fieldCondObj);
    ATLASMagneticFieldWrapper magneticField;
    Acts::MagneticFieldProvider::Cache magFieldCache = magneticField.makeCache( magFieldContext );
    Acts::Vector3 bField = *magneticField.getField( Acts::Vector3(beamPos.x(), beamPos.y(), 0),
                                                    magFieldCache );
 
    // ================================================== // 
    // ===================== COMPUTATION ================ //
    // ================================================== // 
 
    ActsTrk::SpacePointCollector backEnd(selectedSpacePoints);
 
    Acts::SpacePointContainerConfig spConfig;
    spConfig.useDetailedDoubleMeasurementInfo = not m_usePixel;
    // Options
    Acts::SpacePointContainerOptions spOptions;
    spOptions.beamPos = Acts::Vector2(beamPos.x(), beamPos.y());
    
    Acts::SpacePointContainer<decltype(backEnd), Acts::detail::RefHolder> collect(spConfig, spOptions, backEnd);
 
    ATH_MSG_DEBUG("Running Seed Finding ...");    
    time_seedCreation.start();
    ATH_CHECK( m_seedsTool->createSeeds( ctx, 
                     collect,
                     beamPos,
                     bField,
                     *seedPtrs ) );
    time_seedCreation.stop();
    ATH_MSG_DEBUG("    \\__ Created " << seedPtrs->size() << " seeds");
    m_stat[kNSeeds] += seedPtrs->size();
 
    mon_nSeeds = seedPtrs->size();
 
    return StatusCode::SUCCESS;
  }
  
} // namespace