ConcreteVariablesToNtuplePersistenceManager.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 <reconstruction/persistenceManager/ConcreteVariablesToNtuplePersistenceManager.h>
 
#include <framework/utilities/MakeROOTCompatible.h>
#include <framework/utilities/RootFileCreationManager.h>
#include <framework/pcore/ProcHandler.h>
#include <framework/pcore/RootMergeable.h>
 
namespace {
  using namespace Belle2::VariablePersistenceManager;
 
  std::string typedVariableToLeafName(const TypedVariable& variable)
  {
    std::map<VariableDataType, std::string> suffix = {
      {VariableDataType::c_double, "/D"},
      {VariableDataType::c_int, "/I"},
      {VariableDataType::c_bool, "/O"}
    };
 
    std::string branchName = Belle2::MakeROOTCompatible::makeROOTCompatible(variable.getName());
    return branchName + suffix[variable.getDataType()];
  }
}
 
namespace Belle2::VariablePersistenceManager {
  ConcreteVariablesToNtuplePersistenceManager::ConcreteVariablesToNtuplePersistenceManager()
    : m_tree{"", DataStore::c_Persistent}
  {
 
  }
 
  void ConcreteVariablesToNtuplePersistenceManager::initialize(const std::string& fileName,
      const std::string& treeName,
      Variables& variables)
  {
    m_fileName = fileName;
    m_treeName = treeName;
    m_variables = variables;
 
    openFileWithGuards();
    registerBranches();
  }
 
  void ConcreteVariablesToNtuplePersistenceManager::addEntry(const EvaluatedVariables& evaluatedVariables)
  {
    for (const auto& [variableName, value] : evaluatedVariables) {
      std::string branchName = Belle2::MakeROOTCompatible::makeROOTCompatible(variableName.c_str());
      updateBranch(branchName, value);
    }
    m_tree->get().Fill();
  }
 
  void ConcreteVariablesToNtuplePersistenceManager::store()
  {
    if (not ProcHandler::parallelProcessingUsed() or ProcHandler::isOutputProcess()) {
      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.");
      }
    }
  }
 
  void ConcreteVariablesToNtuplePersistenceManager::openFileWithGuards()
  {
    if (m_fileName.empty()) {
      B2FATAL("Output root file name is not set.");
    }
    m_file = RootFileCreationManager::getInstance().getFile(m_fileName);
 
    if (not m_file) {
      B2FATAL("Could not create file: " << m_fileName << ".");
    }
 
    TDirectory::TContext directoryGuard{m_file.get()};
 
    if (m_file->Get(m_treeName.c_str())) {
      B2FATAL("A tree with the name: " << m_treeName << "already exists in the file: " << m_fileName << ".");
    }
 
    m_tree.registerInDataStore(m_fileName + m_treeName, DataStore::c_DontWriteOut);
    m_tree.construct(m_treeName.c_str(), "");
    m_tree->get().SetCacheSize(100000);
  }
 
  void ConcreteVariablesToNtuplePersistenceManager::registerBranches()
  {
    for (const auto& variable : m_variables) {
      std::visit([&](const auto & typedVariable) {
        using T = std::decay_t<decltype(typedVariable)>;
        if constexpr(std::is_same_v<T, TypedVariable>) {
          std::string branchName = Belle2::MakeROOTCompatible::makeROOTCompatible(typedVariable.getName().c_str());
          std::string leafName = typedVariableToLeafName(typedVariable);
 
          switch (typedVariable.getDataType()) {
            case VariableDataType::c_double:
              m_branchesDouble[branchName] = double{};
              m_tree->get().Branch(branchName.c_str(), &m_branchesDouble[branchName], leafName.c_str());
              break;
            case VariableDataType::c_int:
              m_branchesInt[branchName] = int{};
              m_tree->get().Branch(branchName.c_str(), &m_branchesInt[branchName], leafName.c_str());
              break;
            case VariableDataType::c_bool:
              m_branchesBool[branchName] = bool{};
              m_tree->get().Branch(branchName.c_str(), &m_branchesBool[branchName], leafName.c_str());
              break;
            default:
              break;
          }
        } else {
          B2WARNING("Incompatible variable type. Skipping branch registration.");
        }
      }, variable);
    }
    m_tree->get().SetBasketSize("*", m_basketSize);
  }
 
  void ConcreteVariablesToNtuplePersistenceManager::updateBranch(const std::string& branchName,
      const VariableType& evaluatedValue)
  {
    std::visit([&](auto&& value) {
      using T = std::decay_t<decltype(value)>;
 
      if constexpr(std::is_same_v<T, double>) {
        m_branchesDouble[branchName] = value;
      } else if constexpr(std::is_same_v<T, int>) {
        m_branchesInt[branchName] = value;
      } else if constexpr(std::is_same_v<T, bool>) {
        m_branchesBool[branchName] = value;
      }
    }, evaluatedValue);
  }
}