DEventProcessor_ReactionFilter.cc

Go to the documentation of this file.

// $Id$
//
//    File: DEventProcessor_ReactionFilter.cc
// Created: Mon Nov 21 17:54:40 EST 2016
// Creator: pmatt (on Darwin Pauls-MacBook-Pro-2.local 13.4.0 i386)
//

#include "DEventProcessor_ReactionFilter.h"

// Routine used to create our DEventProcessor

extern "C"
{
   void InitPlugin(JApplication *locApplication)
   {
      InitJANAPlugin(locApplication);
      locApplication->AddProcessor(new DEventProcessor_ReactionFilter()); //register this plugin
      locApplication->AddFactoryGenerator(new DFactoryGenerator_ReactionFilter()); //register the factory generator
   }
} // "C"

//------------------
// init
//------------------
jerror_t DEventProcessor_ReactionFilter::init(void)
{
   // This is called once at program startup.

   /*
   //OPTIONAL: Create an EventStore skim.  
   string locSkimFileName = "ReactionFilter.idxa";
   dEventStoreSkimStream.open(locSkimFileName.c_str());
   dEventStoreSkimStream << "IDXA" << endl;
   */

   return NOERROR;
}

//------------------
// brun
//------------------
jerror_t DEventProcessor_ReactionFilter::brun(jana::JEventLoop* locEventLoop, int32_t locRunNumber)
{
   // This is called whenever the run number changes

   return NOERROR;
}

//------------------
// evnt
//------------------
jerror_t DEventProcessor_ReactionFilter::evnt(jana::JEventLoop* locEventLoop, uint64_t locEventNumber)
{
   // This is called for every event. Use of common resources like writing
   // to a file or filling a histogram should be mutex protected. Using
   // locEventLoop->Get(...) to get reconstructed objects (and thereby activating the
   // reconstruction algorithm) should be done outside of any mutex lock
   // since multiple threads may call this method at the same time.

   // DOCUMENTATION:
   // ANALYSIS library: https://halldweb1.jlab.org/wiki/index.php/GlueX_Analysis_Software

   /*********************************************************** REQUIRED ***********************************************************/

   //REQUIRED: To run an analysis, You MUST call one at least of the below code fragments. 
      //JANA is on-demand, so if you don't call one of these, then your analysis won't run. 

   //Recommended: Write surviving particle combinations (if any) to output ROOT TTree
      //If no cuts are performed by the analysis actions added to a DReaction, then this saves all of its particle combinations. 
      //The event writer gets the DAnalysisResults objects from JANA, performing the analysis. 
   // string is DReaction factory tag: will fill trees for all DReactions that are defined in the specified factory
   const DEventWriterROOT* locEventWriterROOT = NULL;
   locEventLoop->GetSingle(locEventWriterROOT);
   locEventWriterROOT->Fill_DataTrees(locEventLoop, "ReactionFilter");

   /******************************************************** OPTIONAL: SKIMS *******************************************************/

   /*
   //Optional: Create an EventStore skim. 

   // See whether this is MC data or real data
   vector<const DMCThrown*> locMCThrowns;
   locEventLoop->Get(locMCThrowns);

   unsigned int locRunNumber = locEventLoop->GetJEvent().GetRunNumber();
   unsigned int locUniqueID = locMCThrowns.empty() ? 1 : Get_FileNumber(locEventLoop);

   // If a particle combo passed the cuts, save the event info in the output file
   for(size_t loc_i = 0; loc_i < locAnalysisResultsVector.size(); ++loc_i)
   {
      const DAnalysisResults* locAnalysisResults = locAnalysisResultsVector[loc_i];
      if(locAnalysisResults->Get_Reaction()->Get_ReactionName() != "ReactionFilter")
         continue; // analysis results were for a different reaction
      if(locAnalysisResults->Get_NumPassedParticleCombos() == 0)
         continue; // no combos passed

      //MUST LOCK AROUND MODIFICATION OF MEMBER VARIABLES IN brun() or evnt().
      japp->WriteLock("ReactionFilter.idxa"); //Lock is unique to this output file
      {
         dEventStoreSkimStream << locRunNumber << " " << locEventNumber << " " << locUniqueID << endl;
      }
      japp->Unlock("ReactionFilter.idxa");
   }
   */

   return NOERROR;
}

int DEventProcessor_ReactionFilter::Get_FileNumber(JEventLoop* locEventLoop) const
{
   //Assume that the file name is in the format: *_X.ext, where:
      //X is the file number (a string of numbers of any length)
      //ext is the file extension (probably .evio or .hddm)

   //get the event source
   JEventSource* locEventSource = locEventLoop->GetJEvent().GetJEventSource();
   if(locEventSource == NULL)
      return -1;

   //get the source file name (strip the path)
   string locSourceFileName = locEventSource->GetSourceName();

   //find the last "_" & "." indices
   size_t locUnderscoreIndex = locSourceFileName.rfind("_");
   size_t locDotIndex = locSourceFileName.rfind(".");
   if((locUnderscoreIndex == string::npos) || (locDotIndex == string::npos))
      return -1;

   size_t locNumberLength = locDotIndex - locUnderscoreIndex - 1;
   string locFileNumberString = locSourceFileName.substr(locUnderscoreIndex + 1, locNumberLength);

   int locFileNumber = -1;
   istringstream locFileNumberStream(locFileNumberString);
   locFileNumberStream >> locFileNumber;

   return locFileNumber;
}

//------------------
// erun
//------------------
jerror_t DEventProcessor_ReactionFilter::erun(void)
{
   // This is called whenever the run number changes, before it is
   // changed to give you a chance to clean up before processing
   // events from the next run number.
   return NOERROR;
}

//------------------
// fini
//------------------
jerror_t DEventProcessor_ReactionFilter::fini(void)
{
   // Called before program exit after event processing is finished.
   if(dEventStoreSkimStream.is_open())
      dEventStoreSkimStream.close();
   return NOERROR;
}