DPL Analysis: Set tables only once for event mixing (#8033)

Author: saganatt

Framework/Core/include/Framework/AnalysisManagers.h

@@ -46,7 +46,7 @@ struct GroupedCombinationManager<GroupedCombinationsGenerator<T1, GroupingPolicy
   {
     static_assert(sizeof...(T2s) > 0, "There must be associated tables in process() for a correct pair");
     static_assert(!soa::is_soa_iterator_t<std::decay_t<H>>::value, "Only full tables can be in process(), no grouping");
-    if constexpr (std::conjunction_v<std::is_same<G, TG>, std::is_same<H, TH>>) {
+    if constexpr (std::is_same_v<G, TG> && std::is_same_v<H, TH>) {
       // Take respective unique associated tables for grouping
       auto associatedTuple = std::tuple<Us...>(std::get<Us>(associated)...);
       comb.setTables(hashes, grouping, associatedTuple);

Framework/Core/include/Framework/GroupedCombinations.h

@@ -231,14 +231,18 @@ struct GroupedCombinationsGenerator<T1, GroupingPolicy, H, G, pack<Us...>, As...
   {
     setTables(hashes, grouping, associated);
   }
+  GroupedCombinationsGenerator(GroupedCombinationsGenerator const&) = default;
+  GroupedCombinationsGenerator& operator=(GroupedCombinationsGenerator const&) = default;
   ~GroupedCombinationsGenerator() = default;
 
   void setTables(H& hashes, G& grouping, std::tuple<Us...>& associated)
   {
-    std::shared_ptr slicer_ptr = std::make_shared<GroupSlicer<G, Us...>>(grouping, associated);
-    mBegin.setTables(hashes, grouping, slicer_ptr);
-    mEnd.setTables(hashes, grouping, slicer_ptr);
-    mEnd.moveToEnd();
+    if (mSlicer == nullptr) {
+      mSlicer = std::make_shared<GroupSlicer<G, Us...>>(grouping, associated);
+      mBegin.setTables(hashes, grouping, mSlicer);
+      mEnd.setTables(hashes, grouping, mSlicer);
+      mEnd.moveToEnd();
+    }
   }
 
  private:
@@ -247,20 +251,21 @@ struct GroupedCombinationsGenerator<T1, GroupingPolicy, H, G, pack<Us...>, As...
   const char* mCategory;
   const int mCatNeighbours;
   const T1 mOutsider;
+  std::shared_ptr<GroupSlicer<G, Us...>> mSlicer = nullptr;
 };
 
 // Aliases for 2-particle correlations
 // 'Pair' and 'Triple' can be used for same kind pair/triple, too, just specify the same type twice
 template <typename H, typename G>
 using joinedCollisions = typename soa::Join<H, G>::table_t;
 template <typename H, typename G, typename A1, typename A2, typename T1 = int, typename GroupingPolicy = o2::soa::CombinationsBlockStrictlyUpperSameIndexPolicy<T1, joinedCollisions<H, G>, joinedCollisions<H, G>>>
-using Pair = GroupedCombinationsGenerator<T1, GroupingPolicy, H, G, unique_pack_t<pack<A1, A2>>>;
+using Pair = GroupedCombinationsGenerator<T1, GroupingPolicy, H, G, unique_pack_t<pack<A1, A2>>, A1, A2>;
 template <typename H, typename G, typename A, typename T1 = int, typename GroupingPolicy = o2::soa::CombinationsBlockStrictlyUpperSameIndexPolicy<T1, joinedCollisions<H, G>, joinedCollisions<H, G>>>
 using SameKindPair = GroupedCombinationsGenerator<T1, GroupingPolicy, H, G, pack<A>, A, A>;
 
 // Aliases for 3-particle correlations
 template <typename H, typename G, typename A1, typename A2, typename A3, typename T1 = int, typename GroupingPolicy = o2::soa::CombinationsBlockStrictlyUpperSameIndexPolicy<T1, joinedCollisions<H, G>, joinedCollisions<H, G>, joinedCollisions<H, G>>>
-using Triple = GroupedCombinationsGenerator<T1, GroupingPolicy, H, G, unique_pack_t<pack<A1, A2, A3>>>;
+using Triple = GroupedCombinationsGenerator<T1, GroupingPolicy, H, G, unique_pack_t<pack<A1, A2, A3>>, A1, A2, A3>;
 template <typename H, typename G, typename A, typename T1 = int, typename GroupingPolicy = o2::soa::CombinationsBlockStrictlyUpperSameIndexPolicy<T1, joinedCollisions<H, G>, joinedCollisions<H, G>, joinedCollisions<H, G>>>
 using SameKindTriple = GroupedCombinationsGenerator<T1, GroupingPolicy, H, G, pack<A>, A, A, A>;