FastMultEst.h

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// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
// All rights not expressly granted are reserved.
//
// This software is distributed under the terms of the GNU General Public
// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
//
// In applying this license CERN does not waive the privileges and immunities
// granted to it by virtue of its status as an Intergovernmental Organization
// or submit itself to any jurisdiction.
 
 
#ifndef ALICEO2_ITS_FASTMULTEST_
#define ALICEO2_ITS_FASTMULTEST_
 
#include "ITSMFTReconstruction/ChipMappingITS.h"
#include "DataFormatsITS/Vertex.h"
#include "DataFormatsITSMFT/ROFRecord.h"
#include "DataFormatsITSMFT/CompCluster.h"
#include "DataFormatsITSMFT/PhysTrigger.h"
#include "ITStracking/FastMultEstConfig.h"
#include "ITStracking/ROFLookupTables.h"
#include <gsl/span>
#include <array>
 
namespace o2::its
{
 
struct FastMultEst {
 
  static constexpr int NLayers = o2::itsmft::ChipMappingITS::NLayers;
  using ROFOverlapTableN = ROFOverlapTable<NLayers>;
  using ROFMaskTableN = ROFMaskTable<NLayers>;
 
  float mult = 0.;             
  float noisePerChip = 0.;     
  float cov[3] = {0.};         
  float chi2 = 0.;             
  int nLayersUsed = 0;         
  uint32_t lastRandomSeed = 0; 
  FastMultEst();
 
  static uint32_t getCurrentRandomSeed();
  int selectROFs(const std::array<gsl::span<const o2::itsmft::ROFRecord>, NLayers>& rofs,
                 const std::array<gsl::span<const o2::itsmft::CompClusterExt>, NLayers>& clus,
                 const gsl::span<const o2::itsmft::PhysTrigger> trig,
                 uint32_t firstTForbit,
                 bool doStaggering,
                 const ROFOverlapTableN::View& overlapView,
                 ROFMaskTableN& sel);
  void selectROFsWithVertices(const auto& vertices, const ROFOverlapTableN::View& overlapView, ROFMaskTableN& sel) const
  {
    const auto& multEstConf = FastMultEstConfig::Instance();
    if (!multEstConf.isVtxMultCutRequested()) {
      return;
    }
 
    for (const auto& vertex : vertices) {
      if (!multEstConf.isPassingVtxMultCut(vertex.getNContributors())) {
        const auto& timestamp{vertex.getTimeStamp()};
        for (int layer = 0; layer < NLayers; ++layer) {
          uint32_t startROF = sel.getLayer(layer).getROF(timestamp.lower());
          uint32_t endROF = sel.getLayer(layer).getROF(timestamp.upper());
          for (uint32_t rof = startROF; rof <= endROF; ++rof) {
            sel.setROFsEnabled(layer, rof, 0);
          }
        }
      }
    }
  }
 
  int countClustersOnLayer(const gsl::span<const o2::itsmft::CompClusterExt>& clusters) const;
  float process(int nClusters)
  {
    return FastMultEstConfig::Instance().imposeNoisePerChip > 0 ? processNoiseImposed(nClusters) : processNoiseFree(nClusters);
  }
  float processNoiseFree(int nClusters);
  float processNoiseImposed(int nClusters);
  float process(const gsl::span<const o2::itsmft::CompClusterExt>& clusters)
  {
    return process(countClustersOnLayer(clusters));
  }
  static bool sSeedSet;
};
 
} // namespace o2::its
 
#endif