add ability to view a span directly

Author: aalkin

ALICE3/Core/FlatLutEntry.cxx

@@ -168,9 +168,6 @@ void FlatLutData::view(const uint8_t* buffer, size_t size)
 void FlatLutData::validateBuffer(const uint8_t* buffer, size_t size)
 {
   auto header = PreviewHeader(buffer, size);
-  if (!header.check_version()) {
-    throw framework::runtime_error_f("LUT header version mismatch: expected %d, got %d", LUTCOVM_VERSION, header.version);
-  }
   auto mNchBins = header.nchmap.nbins;
   auto mRadBins = header.radmap.nbins;
   auto mEtaBins = header.etamap.nbins;
@@ -216,6 +213,11 @@ FlatLutData FlatLutData::ViewFromBuffer(const uint8_t* buffer, size_t size)
   return data;
 }
 
+FlatLutData FlatLutData::ViewFromBuffer(std::span<std::byte> const& span)
+{
+  return ViewFromBuffer(reinterpret_cast<const uint8_t*>(span.data()), span.size_bytes());
+}
+
 bool FlatLutData::isLoaded() const
 {
   return ((!mData.empty()) || (!mDataRef.empty()));

ALICE3/Core/FlatLutEntry.h

@@ -143,6 +143,11 @@ class FlatLutData
    */
   static FlatLutData ViewFromBuffer(const uint8_t* buffer, size_t size);
 
+  /**
+   * @brief Construct a new FlatLutData from external span as a view
+   */
+  static FlatLutData ViewFromBuffer(std::span<std::byte> const& span);
+
   /**
    * @brief Construct a new FlatLutData from a file
    */

ALICE3/Core/FlatTrackSmearer.cxx

@@ -19,7 +19,7 @@
 
 namespace o2::delphes
 {
-int TrackSmearer::getIndexPDG(int pdg) const
+int TrackSmearer::getIndexPDG(int pdg)
 {
   switch (std::abs(pdg)) {
     case 11:
@@ -45,7 +45,7 @@ int TrackSmearer::getIndexPDG(int pdg) const
   }
 }
 
-const char* TrackSmearer::getParticleName(int pdg) const
+const char* TrackSmearer::getParticleName(int pdg)
 {
   switch (std::abs(pdg)) {
     case 11:
@@ -165,6 +165,11 @@ bool TrackSmearer::viewTable(int pdg, const uint8_t* buffer, size_t size, bool f
   return true;
 }
 
+bool TrackSmearer::viewTable(int pdg, std::span<std::byte> const& span, bool forceReload)
+{
+  return viewTable(pdg, reinterpret_cast<const uint8_t*>(span.data()), span.size_bytes(), forceReload);
+}
+
 bool TrackSmearer::hasTable(int pdg) const
 {
   const int ipdg = getIndexPDG(pdg);
@@ -213,8 +218,8 @@ const lutEntry_t* TrackSmearer::getLUTEntry(const int pdg, const float nch, cons
   auto ipt = header.ptmap.find(pt);
 
   // Interpolate efficiency if requested
-  auto fraction = header.nchmap.fracPositionWithinBin(nch);
   if (mInterpolateEfficiency) {
+    auto fraction = header.nchmap.fracPositionWithinBin(nch);
     static constexpr float kFractionThreshold = 0.5f;
     if (fraction > kFractionThreshold) {
       switch (mWhatEfficiency) {

ALICE3/Core/FlatTrackSmearer.h

@@ -32,6 +32,7 @@ class TrackSmearer
   bool loadTable(int pdg, const char* filename, bool forceReload = false);
   bool adoptTable(int pdg, const uint8_t* buffer, size_t size, bool forceReload = false);
   bool viewTable(int pdg, const uint8_t* buffer, size_t size, bool forceReload = false);
+  bool viewTable(int pdg, std::span<std::byte> const& span, bool forceReload = false);
   bool hasTable(int pdg) const;
 
   void useEfficiency(bool val) { mUseEfficiency = val; }
@@ -51,9 +52,8 @@ class TrackSmearer
   double getAbsEtaRes(int pdg, float nch, float eta, float pt) const;
   double getEfficiency(int pdg, float nch, float eta, float pt) const;
 
-  int getIndexPDG(int pdg) const;
-
-  const char* getParticleName(int pdg) const;
+  static int getIndexPDG(int pdg);
+  static const char* getParticleName(int pdg);
 
   void setdNdEta(float val) { mdNdEta = val; }
   void setCcdbManager(o2::ccdb::BasicCCDBManager* mgr) { mCcdbManager = mgr; }
@@ -71,7 +71,7 @@ class TrackSmearer
  private:
   o2::ccdb::BasicCCDBManager* mCcdbManager = nullptr;
 
-  bool checkSpecialCase(int pdg, lutHeader_t const& header);
+  static bool checkSpecialCase(int pdg, lutHeader_t const& header);
 };
 
 } // namespace o2::delphes