Herwig7Interface.cc

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#include <iostream>
#include <fstream>
#include <sstream>
#include <cstdlib>
#include <memory>
#include <cmath>
#include <cstdlib>

#include <algorithm>

#include <boost/shared_ptr.hpp>
#include <boost/filesystem.hpp>

#include <HepMC/GenEvent.h>
#include <HepMC/PdfInfo.h>
#include <HepMC/IO_GenEvent.h>

#include <Herwig/API/HerwigAPI.h>

#include <ThePEG/Utilities/DynamicLoader.h>
#include <ThePEG/Repository/Repository.h>
#include <ThePEG/Handlers/EventHandler.h>
#include <ThePEG/Handlers/XComb.h>
#include <ThePEG/EventRecord/Event.h>
#include <ThePEG/EventRecord/Particle.h> 
#include <ThePEG/EventRecord/Collision.h>
#include <ThePEG/EventRecord/TmpTransform.h>
#include <ThePEG/Config/ThePEG.h>
#include <ThePEG/PDF/PartonExtractor.h>
#include <ThePEG/PDF/PDFBase.h>
#include <ThePEG/Utilities/UtilityBase.h>
#include <ThePEG/Vectors/HepMCConverter.h>


#include "FWCore/MessageLogger/interface/MessageLogger.h"

#include "GeneratorInterface/Core/interface/ParameterCollector.h"

#include "GeneratorInterface/Herwig7Interface/interface/Proxy.h"
#include "GeneratorInterface/Herwig7Interface/interface/RandomEngineGlue.h"
#include "GeneratorInterface/Herwig7Interface/interface/Herwig7Interface.h"

using namespace std;
using namespace gen;

Herwig7Interface::Herwig7Interface(const edm::ParameterSet &pset) :
    randomEngineGlueProxy_(ThePEG::RandomEngineGlue::Proxy::create()),
    dataLocation_(ParameterCollector::resolve(pset.getParameter<string>("dataLocation"))),
    generator_(pset.getParameter<string>("generatorModule")),
    run_(pset.getParameter<string>("run")),
    dumpConfig_(pset.getUntrackedParameter<string>("dumpConfig", "HerwigConfig.in")),
    skipEvents_(pset.getUntrackedParameter<unsigned int>("skipEvents", 0))
{
    // Write events in hepmc ascii format for debugging purposes
    string dumpEvents = pset.getUntrackedParameter<string>("dumpEvents", "");
    if (!dumpEvents.empty()) {
        iobc_.reset(new HepMC::IO_GenEvent(dumpEvents.c_str(), ios::out));
        edm::LogInfo("ThePEGSource") << "Event logging switched on (=> " << dumpEvents << ")";
    }
    // Clear dumpConfig target
    if (!dumpConfig_.empty())
        ofstream cfgDump(dumpConfig_.c_str(), ios_base::trunc);
}

Herwig7Interface::~Herwig7Interface () noexcept
{
    if (eg_)
        eg_->finalize();
    edm::LogInfo("Herwig7Interface") << "Event generator finalized";
}

void Herwig7Interface::setPEGRandomEngine(CLHEP::HepRandomEngine* v) {
        randomEngineGlueProxy_->setRandomEngine(v);
        ThePEG::RandomEngineGlue *rnd = randomEngineGlueProxy_->getInstance();
        if(rnd) {
          rnd->setRandomEngine(v);
        }
}


void Herwig7Interface::initRepository(const edm::ParameterSet &pset)
{
    std::string runModeTemp = pset.getUntrackedParameter<string>("runModeList","read,run");

    // To Lower
    std::transform(runModeTemp.begin(), runModeTemp.end(), runModeTemp.begin(), ::tolower);



    while(!runModeTemp.empty())
    {
        // Split first part of List
        std::string choice;
        size_t pos = runModeTemp.find(",");
        if (std::string::npos == pos)
            choice=runModeTemp;
        else
            choice = runModeTemp.substr(0, pos);
        
        if (pos == std::string::npos)
            runModeTemp.erase();
        else
            runModeTemp.erase(0, pos+1);

        // construct HerwigUIProvider object and return it as global object
        HwUI_ = new Herwig::HerwigUIProvider(pset, dumpConfig_, Herwig::RunMode::READ);
        edm::LogInfo("Herwig7Interface") << "HerwigUIProvider object with run mode " << HwUI_->runMode() << " created.\n";


        // Chose run mode
        if  ( choice == "read" )
        {
            createInputFile(pset);
            HwUI_->setRunMode(Herwig::RunMode::READ, pset, dumpConfig_);
            edm::LogInfo("Herwig7Interface") << "Input file " << dumpConfig_ << " will be passed to Herwig for the read step.\n";
            callHerwigGenerator();
        }
        else if ( choice == "build" )
        {
            createInputFile(pset);
            HwUI_->setRunMode(Herwig::RunMode::BUILD, pset, dumpConfig_);
            edm::LogInfo("Herwig7Interface") << "Input file " << dumpConfig_ << " will be passed to Herwig for the build step.\n";
            callHerwigGenerator();

        }
        else if ( choice == "integrate" )
        {
            std::string runFileName = run_ + ".run";
            edm::LogInfo("Herwig7Interface") << "Run file " << runFileName << " will be passed to Herwig for the integrate step.\n";
            HwUI_->setRunMode(Herwig::RunMode::INTEGRATE, pset, runFileName);
            callHerwigGenerator();

        }
        else if ( choice == "run" )
        {
            std::string runFileName = run_ + ".run";
            edm::LogInfo("Herwig7Interface") << "Run file " << runFileName << " will be passed to Herwig for the run step.\n";
            HwUI_->setRunMode(Herwig::RunMode::RUN, pset, runFileName);
        }
        else
        {
            edm::LogInfo("Herwig7Interface") << "Cannot recognize \"" << choice << "\".\n"
                             << "Trying to skip step.\n";
            continue;
        }

    }

}

void Herwig7Interface::callHerwigGenerator()
{
  try {

    edm::LogInfo("Herwig7Interface") << "callHerwigGenerator function invoked with run mode " << HwUI_->runMode() << ".\n";

    // Call program switches according to runMode
    switch ( HwUI_->runMode() ) {
    case Herwig::RunMode::INIT:        Herwig::API::init(*HwUI_);       break;
    case Herwig::RunMode::READ:        Herwig::API::read(*HwUI_);       break;
    case Herwig::RunMode::BUILD:       Herwig::API::build(*HwUI_);      break;
    case Herwig::RunMode::INTEGRATE:   Herwig::API::integrate(*HwUI_);  break;
    case Herwig::RunMode::MERGEGRIDS:  Herwig::API::mergegrids(*HwUI_); break;
    case Herwig::RunMode::RUN:         eg_ =  Herwig::API::prepareRun(*HwUI_); break;
    case Herwig::RunMode::ERROR:       
      edm::LogError("Herwig7Interface") << "Error during read in of command line parameters.\n"
                << "Program execution will stop now."; 
      return;
    default:                     
      HwUI_->quitWithHelp();
    }

    return;

  }
  catch ( ThePEG::Exception & e ) {
    edm::LogError("Herwig7Interface") << ": ThePEG::Exception caught.\n"
              << e.what() << '\n'
              << "See logfile for details.\n";
    return;
  }
  catch ( std::exception & e ) {
    edm::LogError("Herwig7Interface") << ": " << e.what() << '\n';
    return;
  }
  catch ( const char* what ) {
    edm::LogError("Herwig7Interface") << ": caught exception: "
          << what << "\n";
    return;
  }

}


bool Herwig7Interface::initGenerator()
{
    if ( HwUI_->runMode() == Herwig::RunMode::RUN) {
        edm::LogInfo("Herwig7Interface") << "Starting EventGenerator initialization";
        callHerwigGenerator();
        edm::LogInfo("Herwig7Interface") << "EventGenerator initialized";

        // Skip events
        for (unsigned int i = 0; i < skipEvents_; i++) {
            flushRandomNumberGenerator();
            eg_->shoot();
            edm::LogInfo("Herwig7Interface") << "Event discarded";
        }

        return true;

    } else {
        edm::LogInfo("Herwig7Interface") << "Stopped EventGenerator due to missing run mode.";
        return false;
/*
        throw cms::Exception("Herwig7Interface")
            << "EventGenerator could not be initialized due to wrong run mode!" << endl;
*/
    }

}

void Herwig7Interface::flushRandomNumberGenerator()
{
    /*ThePEG::RandomEngineGlue *rnd = randomEngineGlueProxy_->getInstance();

    if (!rnd)
        edm::LogWarning("ProxyMissing")
            << "ThePEG not initialised with RandomEngineGlue.";
    else
        rnd->flush();
      */
}

auto_ptr<HepMC::GenEvent> Herwig7Interface::convert(
                    const ThePEG::EventPtr &event)
{
    return std::auto_ptr<HepMC::GenEvent>(
        ThePEG::HepMCConverter<HepMC::GenEvent>::convert(*event));
}




double Herwig7Interface::pthat(const ThePEG::EventPtr &event)
{
    using namespace ThePEG;

    if (!event->primaryCollision())
        return -1.0;

    tSubProPtr sub = event->primaryCollision()->primarySubProcess();
    TmpTransform<tSubProPtr> tmp(sub, Utilities::getBoostToCM(
                            sub->incoming()));

    double pthat = (*sub->outgoing().begin())->momentum().perp() / ThePEG::GeV;
    for(PVector::const_iterator it = sub->outgoing().begin();
        it != sub->outgoing().end(); ++it)
        pthat = std::min<double>(pthat, (*it)->momentum().perp() / ThePEG::GeV);

    return pthat;
}




void Herwig7Interface::createInputFile(const edm::ParameterSet &pset)
{
    /* Initialize the input config for Herwig from
     * 1. the Herwig7 config files
     * 2. the CMSSW config blocks
     * Writes them to an output file which is read by Herwig
    */

    stringstream logstream;


    // Contains input config passed to Herwig
    stringstream herwiginputconfig;

    // Define output file to which input config is written, too, if dumpConfig parameter is set. 
    // Otherwise use default file HerwigConfig.in which is read in by Herwig
    ofstream cfgDump;
    cfgDump.open(dumpConfig_.c_str(), ios_base::app);
    


    // Read Herwig config files as input
    vector<string> configFiles = pset.getParameter<vector<string> >("configFiles");
    // Loop over the config files
    for ( const auto & iter : configFiles ) {
        // Open external config file
        ifstream externalConfigFile (iter);
        if (externalConfigFile.is_open()) {
            edm::LogInfo("Herwig7Interface") << "Reading config file (" << iter << ")" << endl;
            stringstream configFileStream;
            configFileStream << externalConfigFile.rdbuf();
            string configFileContent = configFileStream.str();
            
            // Comment out occurence of saverun in config file since it is set later considering run and generator option
            string searchKeyword("saverun");
            if(configFileContent.find(searchKeyword) !=std::string::npos) {
                edm::LogInfo("Herwig7Interface") << "Commented out saverun command in external input config file(" << iter << ")" << endl;
                configFileContent.insert(configFileContent.find(searchKeyword),"#");
            }
            herwiginputconfig << "# Begin Config file input" << endl  << configFileContent << endl << "# End Config file input";
            edm::LogInfo("Herwig7Interface") << "Finished reading config file (" << iter << ")" << endl;
        }
        else {
            edm::LogWarning("Herwig7Interface") << "Could not read config file (" << iter << ")" << endl;
        }
    }

    edm::LogInfo("Herwig7Interface") << "Start with processing CMSSW config" << endl;
    // Read CMSSW config file parameter sets starting from "parameterSets"
    ParameterCollector collector(pset);
    ParameterCollector::const_iterator iter;
    iter = collector.begin();
    herwiginputconfig << endl << "# Begin Parameter set input\n" << endl;
    for(; iter != collector.end(); ++iter) {
        herwiginputconfig << *iter << endl;
    }

    // Add some additional necessary lines to the Herwig input config
    herwiginputconfig << "saverun " << run_ << " " << generator_ << endl;
    // write the ProxyID for the RandomEngineGlue to fill its pointer in
    ostringstream ss;
    ss << randomEngineGlueProxy_->getID();
    //herwiginputconfig << "set " << generator_ << ":RandomNumberGenerator:ProxyID " << ss.str() << endl;


    // Dump Herwig input config to file, so that it can be read by Herwig
    cfgDump << herwiginputconfig.str() << endl;
    cfgDump.close();
}