add functionality to save ngenevt on a run-level in new histogram

- add check for opening a new file
- access the run process history to get the number of generated events
- add new histogram to save ngenevt, paralleling fTotalPOT

Author: lynnt20

sbncode/CAFMaker/CAFMaker_module.cc

@@ -207,6 +207,8 @@ class CAFMaker : public art::EDProducer {
 
   std::string fSourceFile;
   std::uint32_t fSourceFileHash;
+
+  bool fNewInputFile;
 
   bool fOverrideRealData;
   bool fFirstInSubRun;
@@ -224,6 +226,7 @@ class CAFMaker : public art::EDProducer {
   double fTotalEvents;
   double fBlindEvents;
   double fPrescaleEvents;
+  double fNGenEvents;
   std::vector<caf::SRBNBInfo> fBNBInfo; ///< Store detailed BNB info to save into the first StandardRecord of the output file
   std::vector<caf::SRNuMIInfo> fNuMIInfo; ///< Store detailed NuMI info to save into the first StandardRecord of the output file
   std::map<unsigned int,sbn::BNBSpillInfo> fBNBInfoEventMap; ///< Store detailed BNB info to save for the particular spills of events
@@ -783,6 +786,7 @@ void CAFMaker::respondToOpenInputFile(const art::FileBlock& fb) {
   // so should be less than or equal to 32-bit
   fSourceFileHash = static_cast<std::uint32_t>(fSourceFileHashFull);
 
+  fNewInputFile = true;
 }
 
 //......................................................................
@@ -858,6 +862,18 @@ void CAFMaker::beginRun(art::Run& run) {
     fDet = override;
   }
 
+  if (std::exchange(fNewInputFile, false)){
+    for (const art::ProcessConfiguration &process: run.processHistory()) {
+      std::optional<fhicl::ParameterSet> gen_config = run.getProcessParameterSet(process.processName());
+      if (gen_config && gen_config->has_key("source") && gen_config->has_key("source.maxEvents") && gen_config->has_key("source.module_type") ) {
+        int max_events = gen_config->get<int>("source.maxEvents");
+        std::string module_type = gen_config->get<std::string>("source.module_type");
+        if (module_type == "EmptyEvent") {
+          fNGenEvents += max_events;
+        }
+      }
+    }
+  }
 
   if(fParams.SystWeightLabels().empty()) return; // no need for globalTree
 
@@ -1212,6 +1228,7 @@ void CAFMaker::InitializeOutfiles()
   fTotalEvents = 0;
   fBlindEvents = 0;
   fPrescaleEvents = 0;
+  fNGenEvents = 0;
   fIndexInFile = SRHeader::NoSourceIndex;
   fFirstInSubRun = false;
   fFirstBlindInSubRun = false;
@@ -2770,11 +2787,11 @@ void CAFMaker::endSubRun(art::SubRun& sr) {
 //......................................................................
   void CAFMaker::AddHistogramsToFile(TFile* outfile,bool isBlindPOT = false, bool isPrescalePOT = false) const
 {
-
   outfile->cd();
 
   TH1* hPOT = new TH1D("TotalPOT", "TotalPOT;; POT", 1, 0, 1);
   TH1* hEvents = new TH1D("TotalEvents", "TotalEvents;; Events", 1, 0, 1);
+  TH1* hGen = new TH1D("NGenEvents", "NGenEvents;; Events", 1, 0, 1);
 
   if (isBlindPOT) {
     hPOT->Fill(0.5,fTotalPOT*(1-(1/fParams.PrescaleFactor()))*GetBlindPOTScale());
@@ -2786,13 +2803,15 @@ void CAFMaker::endSubRun(art::SubRun& sr) {
     hPOT->Fill(0.5,fTotalPOT);
   }
   hEvents->Fill(0.5,fTotalEvents);
+  hGen->Fill(0.5,fNGenEvents);
 
   hPOT->Write();
   hEvents->Write();
+  hGen->Write();
 
   if (fParams.CreateBlindedCAF()) {
     TH1*hBlindEvents = new TH1D("BlindEvents", "BlindEvents;; Events", 1, 0, 1);
-    TH1* hPrescaleEvents = new TH1D("PrescaleEvents", "PrescaleEvents;; Events", 1, 0, 1);
+    TH1*hPrescaleEvents = new TH1D("PrescaleEvents", "PrescaleEvents;; Events", 1, 0, 1);
     hBlindEvents->Fill(0.5, fBlindEvents);
     hPrescaleEvents->Fill(0.5, fPrescaleEvents);
     hBlindEvents->Write();