AliceO2Group · sawenzel · Mar 16, 2022 · Mar 15, 2022
@@ -20,6 +20,12 @@ namespace o2
 namespace conf
 {
 
+enum SimFieldMode {
+  kDefault = 0,
+  kUniform = 1,
+  kCCDB = 2
+};
+
 // configuration struct (which can be passed around)
 struct SimConfigData {
   std::vector<std::string> mActiveModules;    // list of active modules
@@ -50,7 +56,7 @@ struct SimConfigData {
   std::string mCCDBUrl;                       // the URL where to find CCDB
   uint64_t mTimestamp;                        // timestamp in ms to anchor transport simulation to
   int mField;                                 // L3 field setting in kGauss: +-2,+-5 and 0
-  bool mUniformField = false;                 // uniform magnetic field
+  SimFieldMode mFieldMode = kDefault;         // uniform magnetic field
   bool mAsService = false;                    // if simulation should be run as service/deamon (does not exit after run)
   bool mNoGeant = false;                      // if Geant transport should be turned off (when one is only interested in the generated events)
 

@@ -17,6 +17,7 @@
 #include <thread>
 #include <cmath>
 #include <chrono>
+#include <regex>
 
 using namespace o2::conf;
 namespace bpo = boost::program_options;
@@ -48,10 +49,10 @@ void SimConfig::initOptions(boost::program_options::options_description& options
     "chunkSize", bpo::value<unsigned int>()->default_value(500), "max size of primary chunk (subevent) distributed by server")(
     "chunkSizeI", bpo::value<int>()->default_value(-1), "internalChunkSize")(
     "seed", bpo::value<int>()->default_value(-1), "initial seed (default: -1 random)")(
-    "field", bpo::value<std::string>()->default_value("-5"), "L3 field rounded to kGauss, allowed values +-2,+-5 and 0; +-<intKGaus>U for uniform field ")(
+    "field", bpo::value<std::string>()->default_value("-5"), "L3 field rounded to kGauss, allowed values +-2,+-5 and 0; +-<intKGaus>U for uniform field; \"ccdb\" for taking it from CCDB ")(
     "nworkers,j", bpo::value<int>()->default_value(nsimworkersdefault), "number of parallel simulation workers (only for parallel mode)")(
     "noemptyevents", "only writes events with at least one hit")(
-    "CCDBUrl", bpo::value<std::string>()->default_value("ccdb-test.cern.ch:8080"), "URL for CCDB to be used.")(
+    "CCDBUrl", bpo::value<std::string>()->default_value("http://alice-ccdb.cern.ch"), "URL for CCDB to be used.")(
     "timestamp", bpo::value<uint64_t>(), "global timestamp value in ms (for anchoring) - default is now")(
     "asservice", bpo::value<bool>()->default_value(false), "run in service/server mode")(
     "noGeant", bpo::bool_switch(), "prohibits any Geant transport/physics (by using tight cuts)");
@@ -173,8 +174,23 @@ bool SimConfig::resetFromParsedMap(boost::program_options::variables_map const&
   if (vm.count("noemptyevents")) {
     mConfigData.mFilterNoHitEvents = true;
   }
-  mConfigData.mField = std::stoi((vm["field"].as<std::string>()).substr(0, (vm["field"].as<std::string>()).rfind("U")));
-  mConfigData.mUniformField = (vm["field"].as<std::string>()).find("U") != std::string::npos;
+
+  // analyse field options
+  // either: "ccdb" or +-2[U],+-5[U] and 0[U]; +-<intKGaus>U
+  auto& fieldstring = vm["field"].as<std::string>();
+  std::regex re("(ccdb)|([+-]?[250]U?)");
+  if (!std::regex_match(fieldstring, re)) {
+    LOG(error) << "Invalid field option";
+    return false;
+  }
+  if (fieldstring == "ccdb") {
+    mConfigData.mFieldMode = SimFieldMode::kCCDB;
+  } else if (fieldstring.find("U") != std::string::npos) {
+    mConfigData.mFieldMode = SimFieldMode::kUniform;
+  }
+  if (fieldstring != "ccdb") {
+    mConfigData.mField = std::stoi((vm["field"].as<std::string>()).substr(0, (vm["field"].as<std::string>()).rfind("U")));
+  }
   return true;
 }
 

@@ -29,6 +29,7 @@
 #pragma link C++ class o2::conf::ConfigurableParamHelper < o2::conf::DigiParams> + ;
 
 #pragma link C++ enum o2::conf::EG4Physics;
+#pragma link C++ enum o2::conf::SimFieldMode;
 #pragma link C++ struct o2::conf::G4Params + ;
 #pragma link C++ class o2::conf::ConfigurableParamHelper < o2::conf::G4Params> + ;
 

@@ -21,6 +21,7 @@ o2_add_library(DetectorsBase
                        src/BaseDPLDigitizer.cxx
                        src/CTFCoderBase.cxx
                        src/Aligner.cxx
+                       src/SimFieldUtils.cxx
                PUBLIC_LINK_LIBRARIES FairRoot::Base
                                      O2::CommonUtils
                                      O2::DetectorsCommonDataFormats
@@ -48,7 +49,8 @@ o2_target_root_dictionary(DetectorsBase
                                   include/DetectorsBase/MatCell.h
                                   include/DetectorsBase/MatLayerCyl.h
                                   include/DetectorsBase/MatLayerCylSet.h
-                                  include/DetectorsBase/Aligner.h)
+                                  include/DetectorsBase/Aligner.h
+                                  include/DetectorsBase/SimFieldUtils.h)
 
 if(BUILD_SIMULATION)
   o2_add_test(

@@ -0,0 +1,38 @@
+// 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.
+
+/// \file SimFieldUtils.h
+/// \brief Methods to create simulation mag field
+
+#ifndef ALICEO2_BASE_SIMFIELDUTILS_H_
+#define ALICEO2_BASE_SIMFIELDUTILS_H_
+
+namespace o2
+{
+namespace field
+{
+class MagneticField;
+}
+
+namespace base
+{
+
+class SimFieldUtils
+{
+ public:
+  // a common entry point to create the mag field for simulation
+  // based on the simulation configuration in SimConfig
+  static o2::field::MagneticField* const createMagField();
+};
+
+} // namespace base
+} // namespace o2
+#endif
@@ -25,6 +25,7 @@
 #pragma link C++ class o2::base::GeometryManager::MatBudgetExt + ;
 #pragma link C++ class o2::base::MaterialManager + ;
 #pragma link C++ class o2::MaterialManagerParam + ;
+#pragma link C++ class o2::base::SimFieldUtils + ;
 
 #pragma link C++ class o2::base::Ray + ;
 #pragma link C++ class o2::base::MatCell + ;

@@ -0,0 +1,38 @@
+// 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.
+
+#include <DetectorsBase/SimFieldUtils.h>
+#include <Field/MagneticField.h>
+#include <SimConfig/SimConfig.h>
+#include <CCDB/BasicCCDBManager.h>
+#include <DataFormatsParameters/GRPMagField.h>
+
+using namespace o2::base;
+
+o2::field::MagneticField* const SimFieldUtils::createMagField()
+{
+  auto& confref = o2::conf::SimConfig::Instance();
+  // a) take field from CDDB
+  const auto fieldmode = confref.getConfigData().mFieldMode;
+  o2::field::MagneticField* field = nullptr;
+  if (fieldmode == o2::conf::SimFieldMode::kCCDB) {
+    LOG(info) << "Fetching magnetic field from CCDB";
+    auto& ccdb = o2::ccdb::BasicCCDBManager::instance();
+    auto grpmagfield = ccdb.get<o2::parameters::GRPMagField>("GLO/Config/GRPMagField");
+    // TODO: clarify if we need to pass other params such as beam energy/type etc.
+    field = o2::field::MagneticField::createFieldMap(grpmagfield->getL3Current(), grpmagfield->getDipoleCurrent(), grpmagfield->getFieldUniformity());
+  }
+  // b) using the given values on the command line
+  else {
+    field = o2::field::MagneticField::createNominalField(confref.getConfigData().mField, confref.getConfigData().mFieldMode == o2::conf::SimFieldMode::kUniform);
+  }
+  return field;
+}
@@ -45,6 +45,7 @@
 #include <FairLogger.h>
 #include <algorithm>
 #include "DetectorsCommonDataFormats/UpgradesStatus.h"
+#include <DetectorsBase/SimFieldUtils.h>
 #endif
 
 #ifdef ENABLE_UPGRADES
@@ -103,8 +104,7 @@ void build_geometry(FairRunSim* run = nullptr)
   run->SetMaterials("media.geo"); // Materials
 
   // we need a field to properly init the media
-  auto field = o2::field::MagneticField::createNominalField(confref.getConfigData().mField, confref.getConfigData().mUniformField);
-  run->SetField(field);
+  run->SetField(o2::base::SimFieldUtils::createMagField());
 
   // Create geometry
   // we always need the cave

@@ -29,7 +29,8 @@
 #include <SimConfig/SimConfig.h>
 #include <CommonUtils/ConfigurableParam.h>
 #include <CommonUtils/RngHelper.h>
-#include "Field/MagneticField.h"
+#include <DetectorsBase/SimFieldUtils.h>
+#include <Field/MagneticField.h>
 #include <TGeoGlobalMagField.h>
 #include <typeinfo>
 #include <thread>
@@ -76,8 +77,7 @@ class O2PrimaryServerDevice final : public FairMQDevice
 
     // init magnetic field as it might be needed by the generator
     if (TGeoGlobalMagField::Instance()->GetField() == nullptr) {
-      auto field = o2::field::MagneticField::createNominalField(conf.getConfigData().mField, conf.getConfigData().mUniformField);
-      TGeoGlobalMagField::Instance()->SetField(field);
+      TGeoGlobalMagField::Instance()->SetField(o2::base::SimFieldUtils::createMagField());
       TGeoGlobalMagField::Instance()->Lock();
     }