[df] Move FromRNTuple to separate header

For snapshotting RNTuples, we need to include the header file for RNTupleDS in `ActionHelpers.hxx`. To avoid dependency conflicts related to including `ROOT/RDataFrame.hxx`, we move the free `FromRNTuple` functions to a separate header.
root-project · Jun 4, 2024 · 7dab2fe · 7dab2fe
1 parent 291574c
commit 7dab2fe
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Showing 5 changed files with 45 additions and 10 deletions.
diff --git a/tree/dataframe/CMakeLists.txt b/tree/dataframe/CMakeLists.txt
@@ -24,6 +24,7 @@ endif()
 
 if(root7)
   list(APPEND RDATAFRAME_EXTRA_HEADERS ROOT/RNTupleDS.hxx)
+  list(APPEND RDATAFRAME_EXTRA_HEADERS ROOT/RNTupleDSHelpers.hxx)
   list(APPEND RDATAFRAME_EXTRA_DEPS ROOTNTuple)
 endif()
 

diff --git a/tree/dataframe/inc/ROOT/RNTupleDS.hxx b/tree/dataframe/inc/ROOT/RNTupleDS.hxx
@@ -17,7 +17,6 @@
 #ifndef ROOT_RNTupleDS
 #define ROOT_RNTupleDS
 
-#include <ROOT/RDataFrame.hxx>
 #include <ROOT/RDataSource.hxx>
 #include <ROOT/RNTupleUtil.hxx>
 #include <string_view>
@@ -145,15 +144,6 @@ protected:
 };
 
 } // ns Experimental
-
-namespace RDF {
-namespace Experimental {
-RDataFrame FromRNTuple(std::string_view ntupleName, std::string_view fileName);
-RDataFrame FromRNTuple(std::string_view ntupleName, const std::vector<std::string> &fileNames);
-RDataFrame FromRNTuple(ROOT::Experimental::RNTuple *ntuple);
-} // namespace Experimental
-} // namespace RDF
-
 } // ns ROOT
 
 #endif
diff --git a/tree/dataframe/inc/ROOT/RNTupleDSHelpers.hxx b/tree/dataframe/inc/ROOT/RNTupleDSHelpers.hxx
@@ -0,0 +1,42 @@
+/// \file RNTupleDSHelpers.hxx
+/// \ingroup NTuple ROOT7
+/// \author Florine de Geus <florine.de.geus@cern.ch>
+/// \date 2024-06-04
+/// \warning This is part of the ROOT 7 prototype! It will change without notice. It might trigger earthquakes. Feedback
+/// is welcome!
+
+/*************************************************************************
+ * Copyright (C) 1995-2024, Rene Brun and Fons Rademakers.               *
+ * All rights reserved.                                                  *
+ *                                                                       *
+ * For the licensing terms see $ROOTSYS/LICENSE.                         *
+ * For the list of contributors see $ROOTSYS/README/CREDITS.             *
+ *************************************************************************/
+
+#ifndef ROOT_RNTupleDSHelpers
+#define ROOT_RNTupleDSHelpers
+
+#include <ROOT/RDataFrame.hxx>
+#include <ROOT/RNTupleDS.hxx>
+
+namespace ROOT {
+namespace RDF {
+namespace Experimental {
+////////////////////////////////////////////////////////////////////////////////
+/// \brief Create an RDataFrame from an RNTuple.
+///
+/// \param[in] ntupleName The ntuple name
+/// \param[in] fileName The file name
+///
+/// \return An RDataFrame based on the provided RNTuple
+///
+/// \note It is possible to create RNTuple-based dataframes with the standard RDataFrame constructor!
+///
+ROOT::RDataFrame FromRNTuple(std::string_view ntupleName, std::string_view fileName);
+ROOT::RDataFrame FromRNTuple(std::string_view ntupleName, const std::vector<std::string> &fileNames);
+ROOT::RDataFrame FromRNTuple(ROOT::Experimental::RNTuple *ntuple);
+} // namespace Experimental
+} // namespace RDF
+} // namespace ROOT
+
+#endif // ROOT_RNTupleDSHelpers
diff --git a/tree/dataframe/src/RNTupleDS.cxx b/tree/dataframe/src/RNTupleDS.cxx
@@ -19,6 +19,7 @@
 #include <ROOT/RPageStorageFile.hxx>
 #include <ROOT/RNTupleDescriptor.hxx>
 #include <ROOT/RNTupleDS.hxx>
+#include <ROOT/RNTupleDSHelpers.hxx>
 #include <ROOT/RNTupleUtil.hxx>
 #include <ROOT/RPageStorage.hxx>
 #include <string_view>

diff --git a/tree/dataframe/test/datasource_ntuple.cxx b/tree/dataframe/test/datasource_ntuple.cxx
@@ -1,5 +1,6 @@
 #include <ROOT/RDataFrame.hxx>
 #include <ROOT/RNTupleDS.hxx>
+#include <ROOT/RNTupleDSHelpers.hxx>
 #include <ROOT/RVec.hxx>
 
 #include <ROOT/RNTupleModel.hxx>