vepadulano · May 17, 2026 · Jun 2, 2026 · Jun 3, 2026 · Jun 3, 2026 · Oct 5, 2026
@@ -55,18 +55,18 @@ void getTracks(unsigned int mu, FourVectors& tracks) {
 // This makes the example stand-alone
 void FillTree(const char* filename, const char* treeName) {
    if (!gSystem->AccessPathName(filename)) return;
-   TFile f(filename,"RECREATE");
-   TTree t(treeName,treeName);
+   auto f = std::make_unique<TFile>(filename, "RECREATE");
+   auto t = std::make_unique<TTree>(treeName, treeName);
    double b1;
    int b2;
    std::vector<FourVector> tracks;
    std::vector<double> dv {-1,2,3,4};
    std::list<int> sl {1,2,3,4};
-   t.Branch("b1", &b1);
-   t.Branch("b2", &b2);
-   t.Branch("tracks", &tracks);
-   t.Branch("dv", &dv);
-   t.Branch("sl", &sl);
+   t->Branch("b1", &b1);
+   t->Branch("b2", &b2);
+   t->Branch("tracks", &tracks);
+   t->Branch("dv", &dv);
+   t->Branch("sl", &sl);
 
    int nevts = 16000;
    for(int i = 0; i < nevts; ++i) {
@@ -77,11 +77,9 @@ void FillTree(const char* filename, const char* treeName) {
 
       dv.emplace_back(i);
       sl.emplace_back(i);
-      t.Fill();
+      t->Fill();
    }
-   t.Write();
-   f.Close();
-   return;
+   f->Write();
 }
 
 auto fileName = "testIMT.root";

@@ -11,8 +11,10 @@ running chain...
 ctor called
 filter
 foreach: 1
+dtor called
+ctor called
 filter
 foreach: 2
+dtor called
 done
 count: 2
-dtor called
@@ -84,6 +84,7 @@ ROOT_STANDARD_LIBRARY_PACKAGE(ROOTDataFrame
     ROOT/RDF/RJittedVariation.hxx
     ROOT/RDF/RLazyDSImpl.hxx
     ROOT/RDF/RLoopManager.hxx
+    ROOT/RDF/RMaskedEntryRange.hxx
     ROOT/RDF/RMergeableValue.hxx
     ROOT/RDF/RMetaData.hxx
     ROOT/RDF/RNodeBase.hxx

@@ -27,7 +27,8 @@
 namespace ROOT::Internal::RDF {
 class R__CLING_PTRCHECK(off) RCsvDSColumnReader final : public ROOT::Detail::RDF::RColumnReaderBase {
    void *fValuePtr;
-   void *GetImpl(Long64_t) final { return fValuePtr; }
+   void *GetImpl(std::size_t) final { return fValuePtr; }
+   void LoadImpl(const ROOT::Internal::RDF::RMaskedEntryRange &) final {}
 
 public:
    RCsvDSColumnReader(void *valuePtr) : fValuePtr(valuePtr) {}

@@ -99,31 +99,34 @@ public:
    }
 
    template <typename ColType>
-   auto GetValueChecked(unsigned int slot, std::size_t readerIdx, Long64_t entry) -> ColType &
+   auto GetValueChecked(unsigned int slot, std::size_t readerIdx, std::size_t idx) -> ColType &
    {
-      if (auto *val = fValues[slot][readerIdx]->template TryGet<ColType>(entry))
+      if (auto *val = fValues[slot][readerIdx]->template TryGet<ColType>(idx))
          return *val;
 
       throw std::out_of_range{"RDataFrame: Action (" + fHelper.GetActionName() +
                               ") could not retrieve value for column '" + fColumnNames[readerIdx] + "' for entry " +
-                              std::to_string(entry) +
+                              std::to_string(idx) +
                               ". You can use the DefaultValueFor operation to provide a default value, or "
                               "FilterAvailable/FilterMissing to discard/keep entries with missing values instead."};
    }
 
    template <typename... ColTypes, std::size_t... S>
-   void CallExec(unsigned int slot, Long64_t entry, TypeList<ColTypes...>, std::index_sequence<S...>)
+   void CallExec(unsigned int slot, std::size_t idx, TypeList<ColTypes...>, std::index_sequence<S...>)
    {
       ROOT::Internal::RDF::CallGuaranteedOrder{[&](auto &&...args) { return fHelper.Exec(slot, args...); },
-                                               GetValueChecked<ColTypes>(slot, S, entry)...};
-      (void)entry; // avoid unused parameter warning (gcc 12.1)
+                                               GetValueChecked<ColTypes>(slot, S, idx)...};
+      (void)idx; // avoid unused parameter warning (gcc 12.1)
    }
 
-   void Run(unsigned int slot, Long64_t entry) final
+   void Run(unsigned int slot, Long64_t bulkBeginEntry, std::size_t bulkSize) final
    {
-      // check if entry passes all filters
-      if (fPrevNode.CheckFilters(slot, entry))
-         CallExec(slot, entry, ColumnTypes_t{}, TypeInd_t{});
+      const auto mask = fPrevNode.CheckFilters(slot, bulkBeginEntry, bulkSize);
+      std::for_each(fValues[slot].begin(), fValues[slot].end(), [&mask](auto *v) { v->Load(mask); });
+
+      // Assume 1-size bulk for now
+      if (mask[0])
+         CallExec(slot, /*idx=*/0u, ColumnTypes_t{}, TypeInd_t{});
    }
 
    void TriggerChildrenCount() final { fPrevNode.IncrChildrenCount(); }

@@ -63,7 +63,6 @@ public:
    RColumnRegister &GetColRegister() { return fColRegister; }
    RLoopManager *GetLoopManager() { return fLoopManager; }
    unsigned int GetNSlots() const { return fNSlots; }
-   virtual void Run(unsigned int slot, Long64_t entry) = 0;
    virtual void Initialize() = 0;
    virtual void InitSlot(TTreeReader *r, unsigned int slot) = 0;
    virtual void TriggerChildrenCount() = 0;
@@ -92,6 +91,8 @@ public:
 
    virtual std::unique_ptr<RActionBase> MakeVariedAction(std::vector<void *> &&results) = 0;
    virtual std::unique_ptr<RActionBase> CloneAction(void *newResult) = 0;
+
+   virtual void Run(unsigned int slot, Long64_t bulkBeginEntry, std::size_t bulkSize) = 0;
 };
 } // namespace RDF
 } // namespace Internal

@@ -95,22 +95,23 @@ public:
                               "FilterAvailable/FilterMissing to discard/keep entries with missing values instead."};
    }
 
-   void CallExec(unsigned int slot, Long64_t entry)
+   void CallExec(unsigned int slot, std::size_t idx)
    {
       auto &untypedValues = fValueAddresses[slot];
       auto nReaders = fValues[slot].size();
       untypedValues.resize(nReaders);
       for (decltype(nReaders) readerIdx{}; readerIdx < nReaders; readerIdx++)
-         untypedValues[readerIdx] = GetValue(slot, readerIdx, entry);
+         untypedValues[readerIdx] = GetValue(slot, readerIdx, idx);
 
       fHelper.Exec(slot, untypedValues);
    }
 
-   void Run(unsigned int slot, Long64_t entry) final
+   void Run(unsigned int slot, Long64_t bulkBeginEntry, std::size_t bulkSize) final
    {
-
-      if (fPrevNodes.front()->CheckFilters(slot, entry))
-         CallExec(slot, entry);
+      const auto mask = fPrevNodes.front()->CheckFilters(slot, bulkBeginEntry, bulkSize);
+      std::for_each(fValues[slot].begin(), fValues[slot].end(), [&mask](auto *v) { v->Load(mask); });
+      if (mask[0])
+         CallExec(slot, /*idx=*/0u);
    }
 
    void TriggerChildrenCount() final

@@ -166,55 +166,62 @@ public:
       fHelper.InitTask(r, slot);
    }
 
-   void *GetValue(unsigned int slot, std::size_t readerIdx, Long64_t entry)
+   void *GetValue(unsigned int slot, std::size_t readerIdx, std::size_t idx)
    {
       assert(slot < fValues.size());
       assert(readerIdx < fValues[slot].size());
-      if (auto *val = fValues[slot][readerIdx]->template TryGet<void>(entry))
+      if (auto *val = fValues[slot][readerIdx]->template TryGet<void>(idx))
          return val;
 
       throw std::out_of_range{"RDataFrame: Action (" + fHelper.GetActionName() +
                               ") could not retrieve value for column '" + fColumnNames[readerIdx] + "' for entry " +
-                              std::to_string(entry) +
+                              std::to_string(idx) +
                               ". You can use the DefaultValueFor operation to provide a default value, or "
                               "FilterAvailable/FilterMissing to discard/keep entries with missing values instead."};
    }
 
-   void CallExec(unsigned int slot, Long64_t entry)
+   void CallExec(unsigned int slot, std::size_t idx)
    {
       std::vector<void *> untypedValues;
       auto nReaders = fValues[slot].size();
       untypedValues.reserve(nReaders);
       for (decltype(nReaders) readerIdx{}; readerIdx < nReaders; readerIdx++)
-         untypedValues.push_back(GetValue(slot, readerIdx, entry));
+         untypedValues.push_back(GetValue(slot, readerIdx, idx));
 
       fHelper.Exec(slot, untypedValues);
    }
 
-   void Run(unsigned int slot, Long64_t entry) final
+   void Run(unsigned int slot, Long64_t bulkBeginEntry, std::size_t bulkSize) final
    {
       if constexpr (std::is_same_v<Helper, SnapshotHelperWithVariations>) {
          // check if entry passes all filters
-         std::vector<bool> filterPassed(fPrevNodes.size(), false);
+         std::vector<ROOT::Internal::RDF::RMaskedEntryRange> filterPassed(fPrevNodes.size(), 1ul);
          for (unsigned int variation = 0; variation < fPrevNodes.size(); ++variation) {
-            filterPassed[variation] = fPrevNodes[variation]->CheckFilters(slot, entry);
+            filterPassed[variation] = fPrevNodes[variation]->CheckFilters(slot, bulkBeginEntry, bulkSize);
          }
 
          // Currently, every event where any of nominal or variations pass gets written to the output.
          // This logic could be extended for different use cases if the need arises.
-         if (std::any_of(filterPassed.begin(), filterPassed.end(), [](bool val) { return val; })) {
+         if (std::any_of(filterPassed.begin(), filterPassed.end(),
+                         [](const ROOT::Internal::RDF::RMaskedEntryRange &val) { return val[0]; })) {
             // TODO: Don't allocate
             std::vector<void *> untypedValues;
             auto nReaders = fValues[slot].size();
             untypedValues.reserve(nReaders);
+            std::for_each(fValues[slot].begin(), fValues[slot].end(), [bulkBeginEntry, bulkSize](auto *v) {
+               v->Load(
+                  ROOT::Internal::RDF::RMaskedEntryRange{bulkSize, true, static_cast<std::uint64_t>(bulkBeginEntry)});
+            });
             for (decltype(nReaders) readerIdx{}; readerIdx < nReaders; readerIdx++)
-               untypedValues.push_back(GetValue(slot, readerIdx, entry));
+               untypedValues.push_back(GetValue(slot, readerIdx, /*idx=*/0u));
 
             fHelper.Exec(slot, untypedValues, filterPassed);
          }
       } else {
-         if (fPrevNodes.front()->CheckFilters(slot, entry))
-            CallExec(slot, entry);
+         const auto mask = fPrevNodes.front()->CheckFilters(slot, bulkBeginEntry, bulkSize);
+         std::for_each(fValues[slot].begin(), fValues[slot].end(), [&mask](auto *v) { v->Load(mask); });
+         if (mask[0])
+            CallExec(slot, /*idx=*/0u);
       }
    }
 

@@ -12,6 +12,7 @@
 #define ROOT_INTERNAL_RDF_RCOLUMNREADERBASE
 
 #include <Rtypes.h>
+#include <ROOT/RDF/RMaskedEntryRange.hxx>
 
 namespace ROOT {
 namespace Detail {
@@ -26,23 +27,30 @@ This pure virtual class provides a common base class for the different column re
 RDSColumnReader.
 **/
 class R__CLING_PTRCHECK(off) RColumnReaderBase {
+
 public:
    virtual ~RColumnReaderBase() = default;
 
+   /// Load the column value for the given entry.
+   /// \param entry The entry number to load.
+   /// \param mask The entry mask. Values will be loaded only for entries for which the mask equals true.
+   void Load(const ROOT::Internal::RDF::RMaskedEntryRange &mask) { LoadImpl(mask); }
+
    /// Return the column value for the given entry.
    /// \tparam T The column type
    /// \param entry The entry number
    ///
    /// The caller is responsible for checking that the returned value actually
    /// exists.
    template <typename T>
-   T *TryGet(Long64_t entry)
+   T *TryGet(std::size_t entryInBulk)
    {
-      return static_cast<T *>(GetImpl(entry));
+      return static_cast<T *>(GetImpl(entryInBulk));
    }
 
 private:
-   virtual void *GetImpl(Long64_t entry) = 0;
+   virtual void *GetImpl(std::size_t entryInBulk) = 0;
+   virtual void LoadImpl(const ROOT::Internal::RDF::RMaskedEntryRange &) = 0;
 };
 
 } // namespace RDF

@@ -23,7 +23,8 @@ template <typename T>
 class R__CLING_PTRCHECK(off) RDSColumnReader final : public ROOT::Detail::RDF::RColumnReaderBase {
    T **fDSValuePtr = nullptr;
 
-   void *GetImpl(Long64_t) final { return *fDSValuePtr; }
+   void *GetImpl(std::size_t) final { return *fDSValuePtr; }
+   void LoadImpl(const ROOT::Internal::RDF::RMaskedEntryRange &) final {}
 
 public:
    RDSColumnReader(void *DSValuePtr) : fDSValuePtr(static_cast<T **>(DSValuePtr)) {}

@@ -45,21 +45,22 @@ template <typename T>
 class R__CLING_PTRCHECK(off) RDefaultValueFor final : public RDefineBase {
    using ColumnTypes_t = ROOT::TypeTraits::TypeList<T>;
    using TypeInd_t = std::make_index_sequence<ColumnTypes_t::list_size>;
-   // Avoid instantiating vector<bool> as `operator[]` returns temporaries in that case. Use std::deque instead.
-   using ValuesPerSlot_t = std::conditional_t<std::is_same<T, bool>::value, std::deque<T>, std::vector<T>>;
+
+   using ValuesPerSlot_t = std::vector<ROOT::RVec<T>>;
 
    T fDefaultValue;
-   ValuesPerSlot_t fLastResults;
+   // Each slot accesses a cache of values for the current bulk
+   ValuesPerSlot_t fCachedResultsPerSlot;
    // One column reader per slot
    std::vector<RColumnReaderBase *> fValues;
 
    /// Define objects corresponding to systematic variations other than nominal for this defined column.
    /// The map key is the full variation name, e.g. "pt:up".
    std::unordered_map<std::string, std::unique_ptr<RDefineBase>> fVariedDefines;
 
-   T &GetValueOrDefault(unsigned int slot, Long64_t entry)
+   T &GetValueOrDefault(unsigned int slot, std::size_t idx)
    {
-      if (auto *value = fValues[slot]->template TryGet<T>(entry))
+      if (auto *value = fValues[slot]->template TryGet<T>(idx))
          return *value;
       else
          return fDefaultValue;
@@ -71,12 +72,16 @@ public:
                     RLoopManager &lm, const std::string &variationName = "nominal")
       : RDefineBase(name, type, colRegister, lm, columns, variationName),
         fDefaultValue(defaultValue),
-        fLastResults(lm.GetNSlots() * RDFInternal::CacheLineStep<T>()),
+        fCachedResultsPerSlot(lm.GetNSlots() * RDFInternal::CacheLineStep<ROOT::RVec<T>>()),
         fValues(lm.GetNSlots())
    {
       fLoopManager->Register(this);
       // We suppress errors that TTreeReader prints regarding the missing branch
       fLoopManager->InsertSuppressErrorsForMissingBranch(fColumnNames[0]);
+      // Assume 1-size bulk for now
+      for (decltype(lm.GetNSlots()) i = 0; i < lm.GetNSlots(); ++i) {
+         fCachedResultsPerSlot[i * RDFInternal::CacheLineStep<ROOT::RVec<T>>()].resize(1ul);
+      }
    }
 
    RDefaultValueFor(const RDefaultValueFor &) = delete;
@@ -97,20 +102,30 @@ public:
       fLastCheckedEntry[slot * RDFInternal::CacheLineStep<Long64_t>()] = -1;
    }
 
-   /// Return the (type-erased) address of the Define'd value for the given processing slot.
+   /// Return the beginning of the cached results of the current bulk for the input processing slot
    void *GetValuePtr(unsigned int slot) final
    {
-      return static_cast<void *>(&fLastResults[slot * RDFInternal::CacheLineStep<T>()]);
+      return static_cast<void *>(fCachedResultsPerSlot[slot * RDFInternal::CacheLineStep<ROOT::RVec<T>>()].data());
    }
 
    /// Update the value at the address returned by GetValuePtr with the content corresponding to the given entry
-   void Update(unsigned int slot, Long64_t entry) final
+   void Update(unsigned int slot, const ROOT::Internal::RDF::RMaskedEntryRange &mask) final
    {
-      if (entry != fLastCheckedEntry[slot * RDFInternal::CacheLineStep<Long64_t>()]) {
-         // evaluate this define expression, cache the result
-         fLastResults[slot * RDFInternal::CacheLineStep<T>()] = GetValueOrDefault(slot, entry);
-         fLastCheckedEntry[slot * RDFInternal::CacheLineStep<Long64_t>()] = entry;
+      if (static_cast<Long64_t>(mask.GetFirstEntry()) ==
+          fLastCheckedEntry[slot * RDFInternal::CacheLineStep<Long64_t>()])
+         return;
+
+      // Assume 1-size bulk for now
+      fValues[slot]->Load(mask);
+      const std::size_t bulkSize = fLoopManager->GetCurrentBulkSize();
+      auto &result = fCachedResultsPerSlot[slot * RDFInternal::CacheLineStep<ROOT::RVec<T>>()];
+      result.clear();
+      result.resize(bulkSize);
+      for (std::size_t i = 0; i < bulkSize; ++i) {
+         if (mask[i])
+            fCachedResultsPerSlot[slot * RDFInternal::CacheLineStep<ROOT::RVec<T>>()][i] = GetValueOrDefault(slot, i);
       }
+      fLastCheckedEntry[slot * RDFInternal::CacheLineStep<Long64_t>()] = mask.GetFirstEntry();
    }
 
    void Update(unsigned int /*slot*/, const ROOT::RDF::RSampleInfo & /*id*/) final {}