ParticleMCDecayStringModule.cc

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
 
#include <analysis/modules/ParticleMCDecayString/ParticleMCDecayStringModule.h>
 
#include <analysis/dataobjects/Particle.h>
 
#include <mdst/dataobjects/MCParticle.h>
 
#include <framework/logging/Logger.h>
#include <framework/pcore/ProcHandler.h>
#include <framework/utilities/RootFileCreationManager.h>
 
#include <string>
#include <vector>
 
#include <boost/algorithm/string.hpp>
 
using namespace Belle2;
 
REG_MODULE(ParticleMCDecayString);
 
ParticleMCDecayStringModule::ParticleMCDecayStringModule() : Module(), m_tree("", DataStore::c_Persistent), m_hashset("",
      DataStore::c_Persistent), m_decayHash(0.0), m_decayHashExtended(0.0)
{
  setDescription("Creates the Monte Carlo decay string of a Particle and its daughters. "
                 "The MC decay string of the particle is hashed and saved as a 32bit pattern in the extra info field decayHash of the particle.  "
                 "The MC decay string of the particle + its daughters is hashed as well and saved as another 32bit pattern in the extra info field decayHashExtended of the particle.  "
                 "The mapping hash <-> MC decay string in saved in a TTree by this module.  "
                 "The 32bit pattern must be saved as a float (because our extra info field, variable manager and ntuple output only supports float) "
                 "but they just represent 32 bits of a hash!  "
                 "The MC decay string can also be stored in an analysis ROOT file using the MCDecayString NtupleTool.  "
                 "Details on the MC decay string format can be found here: `MCDecayString`");
  setPropertyFlags(c_ParallelProcessingCertified | c_TerminateInAllProcesses);
  addParam("listName", m_listName, "Particles from these ParticleList are used as input.");
  addParam("fileName", m_fileName, "Filename in which the hash strings are saved, if empty the strings are not saved",
           std::string(""));
  addParam("treeName", m_treeName, "Tree name in which the hash strings are saved", std::string("hashtable"));
  addParam("conciseString", m_useConciseString, "If set to true, the code will use a more concise format for the string.", false);
  addParam("identifiers", m_identifiers, "Identifiers used to identify particles in the concise format.",
           std::string("abcdefghijklmnopqrstuvwxyz"));
}
 
void ParticleMCDecayStringModule::initialize()
{
  m_pList.isRequired(m_listName);
 
  //This might not work for non-default names of Particle array:
  StoreArray<Particle>().isRequired();
 
  m_stringWrapperArray.registerInDataStore();
  StoreArray<Particle>().registerRelationTo(m_stringWrapperArray);
 
 
  // Initializing the output root file
  if (m_fileName != "") {
    m_file = RootFileCreationManager::getInstance().getFile(m_fileName);
    if (!m_file) {
      B2WARNING("Could not create file " << m_fileName);
      return;
    }
 
    m_file->cd();
 
    // check if TTree with that name already exists
    if (m_file->Get(m_treeName.c_str())) {
      B2WARNING("Tree with this name already exists: " << m_fileName);
      return;
    }
 
    m_tree.registerInDataStore(m_fileName + m_treeName, DataStore::c_DontWriteOut);
    m_tree.construct(m_treeName.c_str(), "Decay Hash Map");
    m_tree->get().Branch("decayHash", &m_decayHash);
    m_tree->get().Branch("decayHashExtended", &m_decayHashExtended);
    m_tree->get().Branch("decayString", &m_decayString);
    m_tree->get().SetBasketSize("*", 1600);
    m_tree->get().SetCacheSize(100000);
  }
 
  m_hashset.registerInDataStore(m_fileName + m_treeName + "_hashset", DataStore::c_DontWriteOut);
  m_hashset.construct();
 
}
 
void ParticleMCDecayStringModule::event()
{
 
  for (unsigned iParticle = 0; iParticle < m_pList->getListSize(); ++iParticle) {
    Particle* particle = m_pList->getParticle(iParticle);
 
    const std::string decayString = getMCDecayStringFromMCParticle(particle->getRelatedTo<MCParticle>());
    std::string decayStringExtended = getDecayString(*particle); //removed const to allow string to be modified to a different format.
 
    if (m_useConciseString) {convertToConciseString(decayStringExtended);}
 
    uint32_t decayHash = m_hasher(decayString);
    uint32_t decayHashExtended = m_hasher(decayStringExtended);
 
    uint64_t m_decayHashFull = decayHash;
    m_decayHashFull <<= 32;
    m_decayHashFull += decayHashExtended;
 
    // Convert unsigned int decay hash into a float keeping the same bit pattern
    assert(sizeof(float) == sizeof(uint32_t));
 
    union convert {
      uint32_t i;
      float f;
    };
    convert bitconverter;
 
    bitconverter.i = decayHash;
    m_decayHash = bitconverter.f;
    particle->addExtraInfo(c_ExtraInfoName, m_decayHash);
 
    // cppcheck doesn't like this use of union and throws warnings
    // cppcheck-suppress redundantAssignment
    bitconverter.i = decayHashExtended;
    m_decayHashExtended = bitconverter.f;
    particle->addExtraInfo(c_ExtraInfoNameExtended, m_decayHashExtended);
 
    m_decayString = decayStringExtended;
 
    StringWrapper* stringWrapper = m_stringWrapperArray.appendNew();
    particle->addRelationTo(stringWrapper);
    stringWrapper->setString(m_decayString);
 
    auto it = m_hashset->get().find(m_decayHashFull);
    if (it == m_hashset->get().end()) {
      m_hashset->get().insert(m_decayHashFull);
 
      if (m_tree.isValid()) {
        m_tree->get().Fill();
      }
    }
 
  }
}
 
void ParticleMCDecayStringModule::terminate()
{
  if (!ProcHandler::parallelProcessingUsed() or ProcHandler::isOutputProcess()) {
    if (m_tree.isValid()) {
      B2INFO("Writing NTuple " << m_treeName);
      TDirectory::TContext directoryGuard(m_file.get());
      m_tree->write(m_file.get());
 
      const bool writeError = m_file->TestBit(TFile::kWriteError);
      m_file.reset();
      if (writeError) {
        B2FATAL("A write error occurred while saving '" << m_fileName  << "', please check if enough disk space is available.");
      }
    }
  }
}
 
 
const MCParticle* ParticleMCDecayStringModule::getInitialParticle(const MCParticle* mcP)
{
  const MCParticle* mcPMother = mcP->getMother();
  if (mcPMother == nullptr) {
    return mcP;
  } else {
    return getInitialParticle(mcPMother);
  }
}

bool isFSP(int pdg)
{
  switch (abs(pdg)) {
    case 211:   //pi^+
    case 321:   //K^+
    case 11:    //e
    case 12:    //nu_e
    case 13:    //mu
    case 14:    //nu_mu
    case 16:    //nu_tau
    case 22:    //gamma
    case 310:   //K_S
    case 130:   //K_L
    case 2112:  //n
    case 2212:  //p
      return true;
    default:
      return false;
  }
}
 
std::string ParticleMCDecayStringModule::getDecayString(const Particle& p)
{
 
  std::string output;
  output += getDecayStringFromParticle(&p) + " | ";
  output += getMCDecayStringFromParticle(&p);
  return output;
 
}
 
std::string ParticleMCDecayStringModule::getDecayStringFromParticle(const Particle* p)
{
 
  std::string output = " ";
 
  output += std::to_string(p->getPDGCode());
 
  if (not isFSP(p->getPDGCode())) {
    output += " (-->";
    for (auto daughter : p->getDaughters()) {
      output += getDecayStringFromParticle(daughter);
    }
    output += ")";
  }
 
  return output;
 
}
 
std::string ParticleMCDecayStringModule::getMCDecayStringFromParticle(const Particle* p)
{
 
  std::string output;
 
  output = getMCDecayStringFromMCParticle(p->getRelatedTo<MCParticle>());
  // Some FSPs can have daughters, e.g. converted Photons and K-Shorts
  if (not isFSP(p->getPDGCode())) {
    for (auto& daughter : p->getDaughters()) {
      output += " | " + getMCDecayStringFromParticle(daughter);
    }
  }
 
  return output;
 
}
 
std::string ParticleMCDecayStringModule::getMCDecayStringFromMCParticle(const MCParticle* mcPMatched)
{
 
  if (mcPMatched == nullptr)
    return "(No match)";
 
  // TODO Performance can be optimized, this mcPMother does not change during the construction
  const MCParticle* mcPMother = getInitialParticle(mcPMatched);
 
  std::string decayString = buildMCDecayString(mcPMother, mcPMatched);
 
  if (mcPMatched->getPDG() == 10022)
    return decayString + " (Virtual gamma match)";
  return decayString;
}
 
 
std::string ParticleMCDecayStringModule::buildMCDecayString(const MCParticle* mcPMother, const MCParticle* mcPMatched)
{
 
  std::stringstream ss;
  ss << " ";
  if (mcPMother->getArrayIndex() == mcPMatched->getArrayIndex()) {
    ss << "^";
  }
 
  ss << mcPMother->getPDG();
 
  if (not isFSP(mcPMother->getPDG())) {
    ss << " (-->";
    for (auto daughter : mcPMother->getDaughters()) {
      ss << buildMCDecayString(daughter, mcPMatched);
    }
    ss << ")";
  }
 
  return ss.str();
}
 
void ParticleMCDecayStringModule::convertToConciseString(std::string& string)
{
 
  std::vector<std::string> decayStrings;
  boost::split(decayStrings, string, boost::is_any_of("|"));
 
  if (decayStrings.empty()) {
    B2WARNING("ParticleMCDecayStringModule: unable to convert decay string to concise format.");
    return;
  }
 
  unsigned int nParticles(decayStrings.size() - 1);
  if (nParticles > m_identifiers.size()) {
    B2WARNING("ParticleMCDecayStringModule: not enough identifiers have been specified to use the concise string format:"
              << std::endl << "Number of particles in your decay mode = " << nParticles << std::endl
              << "Available identifiers: " << m_identifiers << std::endl
              << "Standard format will be used instead.");
    return;
  }
 
  //Find positions of carets in original strings, store them, and then erase them.
  std::string mode("");
  std::vector<int> caretPositions;
  for (auto& decayString : decayStrings) {
    std::string thisString(decayString);
    if ("" == mode) {
      mode = thisString;
      continue;
    }
 
    int caretPosition(thisString.find('^')); // -1 if no match.
    caretPositions.push_back(caretPosition);
    if (caretPosition > -1) {
      decayString.erase(caretPosition, 1);
    }
  }
 
  //Check if all of the decay strings are the same (except for No matches):
  std::string theDecayString("");
  for (auto thisString : decayStrings) {
    if (thisString == mode) {continue;}
 
    //last decay string does not have a space at the end, don't want this to stop a match.
    char finalChar(thisString.back());
    if (finalChar != ' ') {thisString = thisString + " ";}
 
    if (" (No match) " != thisString) {
      if ("" == theDecayString) {
        theDecayString = thisString;
      } else {
        if (theDecayString != thisString) {
          //TODO: add string format if multiple decay strings are present (e.g. pile-up events).
          return;
        }
      }
    }
  }
 
  std::string modifiedString(theDecayString);
 
  //insert identifiers in positions where carets were:
  int nStrings(caretPositions.size());
  for (int iString(0); iString < nStrings; ++iString) {
    std::string identifier(m_identifiers.substr(iString, 1));
    int insertPosition(caretPositions.at(iString));
    if (insertPosition > -1) {
      for (int jString(0); jString < iString; ++jString) {
        if (caretPositions.at(jString) > -1 && caretPositions.at(jString) <= caretPositions.at(iString)) {
          ++insertPosition;
        }
      }
      modifiedString.insert(insertPosition, identifier);
    }
  }
 
  modifiedString = mode + "|" + modifiedString;
 
  //add a list of the unmatched particles at the end of the string:
  bool noMatchStringAdded(false);
  for (int iString(0); iString < nStrings; ++iString) {
    int insertPosition(caretPositions.at(iString));
    if (-1 == insertPosition) {
      if (!noMatchStringAdded) {
        modifiedString += " | No match: ";
        noMatchStringAdded = true;
      }
      modifiedString += m_identifiers.substr(iString, 1);
    }
  }
 
  string = modifiedString;
  return;
}