TRD digi / O2-5395: Trivial collision cut

Author: sawenzel

Detectors/TRD/workflow/src/TRDDigitizerSpec.cxx

@@ -32,6 +32,7 @@
 #include "TRDSimulation/Digitizer.h"
 #include "TRDSimulation/Detector.h" // for the Hit type
 #include "TRDSimulation/TRDSimParams.h"
+#include "DetectorsRaw/HBFUtils.h"
 #include <chrono>
 
 using namespace o2::framework;
@@ -92,6 +93,8 @@ class TRDDPLDigitizerTask : public o2::base::BaseDPLDigitizer
     size_t currTrig = 0;                    // from which collision is the current TRD trigger (only needed for debug information)
     bool firstEvent = true;                 // Flag for the first event processed
 
+    auto firstTF = InteractionTimeRecord(o2::raw::HBFUtils::Instance().getFirstSampledTFIR(), 0);
+
     TStopwatch timer;
     timer.Start();
     // loop over all composite collisions given from context
@@ -100,6 +103,16 @@ class TRDDPLDigitizerTask : public o2::base::BaseDPLDigitizer
       LOGF(debug, "Collision %lu out of %lu at %.1f ns started processing. Current pileup container size: %lu. Current number of digits accumulated: %lu",
            collID, irecords.size(), irecords[collID].getTimeNS(), mDigitizer.getPileupSignals().size(), digitsAccum.size());
       currentTime = irecords[collID];
+
+      // Note: Very crude filter to neglect collisions coming before
+      // the first interaction record of the timeframe. Remove this, once these collisions can be handled
+      // within the digitization routine. Collisions before this timeframe might impact digits of this timeframe.
+      // See https://its.cern.ch/jira/browse/O2-5395.
+      if (currentTime < firstTF) {
+        LOG(info) << "Too early: Not digitizing collision " << collID;
+        continue;
+      }
+
       // Trigger logic implemented here
       bool isNewTrigger = true; // flag newly accepted readout trigger
       if (firstEvent) {