Common: save only non-empty BCs, add BC flags creator

Common/TableProducer/Converters/CMakeLists.txt

@@ -49,6 +49,11 @@ o2physics_add_dpl_workflow(bc-converter
                     PUBLIC_LINK_LIBRARIES O2::Framework
                 COMPONENT_NAME Analysis)
 
+o2physics_add_dpl_workflow(bc-flags-creator
+                    SOURCES bcFlagsCreator.cxx
+                    PUBLIC_LINK_LIBRARIES O2::Framework
+                COMPONENT_NAME Analysis)
+
 o2physics_add_dpl_workflow(calo-label-converter
                     SOURCES caloLabelConverter.cxx
                     PUBLIC_LINK_LIBRARIES

Common/TableProducer/Converters/bcFlagsCreator.cxx

@@ -0,0 +1,36 @@
+// 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 "Framework/runDataProcessing.h"
+#include "Framework/AnalysisTask.h"
+#include "Framework/AnalysisDataModel.h"
+
+using namespace o2;
+using namespace o2::framework;
+
+// Creates an empty BCFlags for data that doesn't have it to be used seamlessly
+// n.b. this will overwrite existing BCFlags, to be discussed if data in mixed condition
+struct bcFlagsCreator {
+  Produces<aod::BCFlags> bcFlags;
+
+  void process(aod::BCs const& bcTable)
+  {
+    for (auto& bc : bcTable) {
+      bcFlags(0);
+    }
+  }
+};
+
+WorkflowSpec defineDataProcessing(ConfigContext const& cfgc)
+{
+  return WorkflowSpec{
+    adaptAnalysisTask<bcFlagsCreator>(cfgc),
+  };
+}

Common/TableProducer/multiplicityExtraTable.cxx

@@ -39,6 +39,7 @@ struct MultiplicityExtraTable {
   // Allow for downscaling of BC table for less space use in derived data
   Configurable<float> bcDownscaleFactor{"bcDownscaleFactor", 2, "Downscale factor for BC table (0: save nothing, 1: save all)"};
   Configurable<float> minFT0CforBCTable{"minFT0CforBCTable", 25.0f, "Minimum FT0C amplitude to fill BC table to reduce data"};
+  Configurable<bool> saveOnlyBCsWithCollisions{"saveOnlyBCsWithCollisions", true, "save only BCs with collisions in them"};
 
   // needed for downscale
   unsigned int randomSeed = 0;
@@ -66,13 +67,24 @@ struct MultiplicityExtraTable {
   {
     //+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+
     // determine saved BCs and corresponding new BC table index
+    std::vector<int> bcHasCollision(bcs.size());
     std::vector<int> newBCindex(bcs.size());
     std::vector<int> bc2multArray(bcs.size());
     int atIndex = 0;
     for (const auto& bc : bcs) {
+      bcHasCollision[bc.globalIndex()] = false;
       newBCindex[bc.globalIndex()] = -1;
       bc2multArray[bc.globalIndex()] = -1;
+    }
+
+    //+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+
+    // tag BCs that have a collision
+    for (const auto& collision : collisions) {
+      bcHasCollision[collision.foundBCId()] = true;
+    }
+    //+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+
 
+    for (const auto& bc : bcs) {
       // downscale if requested to do so
       if (bcDownscaleFactor < 1.f && (static_cast<float>(rand_r(&randomSeed)) / static_cast<float>(RAND_MAX)) > bcDownscaleFactor) {
         continue;
@@ -91,6 +103,11 @@ struct MultiplicityExtraTable {
       if (multFT0C < minFT0CforBCTable) {
         continue; // skip this event
       }
+
+      if (saveOnlyBCsWithCollisions && !bcHasCollision[bc.globalIndex()]){
+        continue; // skip if no collision is assigned to this BC (from evSel assignment)
+      }
+
       newBCindex[bc.globalIndex()] = atIndex++;
     }
     //+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+-<*>-+