Fix several minor issues

CMakeLists.txt

@@ -44,6 +44,18 @@ if(NOT DEFINED ROOTSYS)
 endif()
 get_filename_component(ROOT_LIBRARY_DIR "${ROOTSYS}/lib" ABSOLUTE)
 
+#---Several benchmarks rely on hadd in their setup fixtures, so make sure it is available.
+if(CMAKE_PROJECT_NAME STREQUAL ROOT)
+  # When building as part of ROOT, hadd is built in the same build tree and
+  # does not exist yet at configuration time.
+  set(RB_HADD_EXECUTABLE ${CMAKE_BINARY_DIR}/bin/hadd)
+else()
+  find_program(RB_HADD_EXECUTABLE hadd HINTS ${ROOTSYS}/bin)
+  if(NOT RB_HADD_EXECUTABLE)
+    message(FATAL_ERROR "hadd was not found, neither in PATH nor in ${ROOTSYS}/bin. It is required by several benchmarks, please make sure it is provided by your ROOT installation.")
+  endif()
+endif()
+
 #---Define useful ROOT functions and macros (e.g. ROOT_GENERATE_DICTIONARY)
 include(${ROOT_USE_FILE})
 

README.md

@@ -39,6 +39,13 @@ also, you can use
 cmake --build . -- -jN
 ```
 where 'N' is the maximum number of processor cores you want to use.
+
+### Runtime environment variables
+Some benchmarks write temporary files while they run. The directory used for these files can be chosen with the `RB_TEMP_FS` environment variable before invoking the benchmarks (e.g. via `ctest`):
+```bash
+export RB_TEMP_FS=/dev/shm
+```
+Ideally this points to a RAM-backed filesystem such as `/dev/shm` on Linux, so that disk I/O does not distort the measurements. If the variable is not set, the current working directory is used and a notice is printed.
 ## Extending the benchmarks
 ROOTBench relies on [Google Benchmark](https://github.com/google/benchmark). We recommend to read the [available documentation](https://github.com/google/benchmark/blob/master/README.md) and browse the existing examples [here](https://github.com/google/benchmark/tree/master/test) for more advanced usage.
 

cmake/modules/AddRootBench.cmake

@@ -101,7 +101,7 @@ function(RB_ADD_PYTESTBENCHMARK benchmark)
     endif()
     set(filename ${ARG_UNPARSED_ARGUMENTS})
 
-    if(PYTEST_FOUND)
+    if(RB_PYTEST_FOUND)
       if(ARG_DOWNLOAD_DATAFILES)
           RB_ADD_DOWNLOAD_FIXTURE(${benchmark} DOWNLOAD_DATAFILES ${ARG_DOWNLOAD_DATAFILES})
       endif()
@@ -119,7 +119,7 @@ function(RB_ADD_PYTESTBENCHMARK benchmark)
                            TIMEOUT "${TIMEOUT_VALUE}" LABELS "${ARG_LABEL}" RUN_SERIAL TRUE
                            FIXTURES_REQUIRED "setup-${benchmark};download-${benchmark}-datafiles")
     else()
-      message(STATUS "pytest was not found, benchmark " ${benchmark} " will be ignored")
+      message(STATUS "Python modules required for pytest benchmarks were not found, benchmark " ${benchmark} " will be ignored")
     endif()
 
   else()

cmake/modules/PytestBenchmark.cmake

@@ -25,10 +25,21 @@ if(NOT (CMAKE_PROJECT_NAME STREQUAL ROOT))
   endif()
 endif()
 
-# Find mandatory dependency (for Python benchmarks), but quietly :)
-find_python_module(pytest QUIET)
+# Find mandatory dependencies (for Python benchmarks), but quietly :)
+set(RB_PYTEST_MISSING_MODULES)
+foreach(module pytest pytest_benchmark pytest_csv)
+  find_python_module(${module} QUIET)
+  string(TOUPPER ${module} module_upper)
+  if(NOT ${module_upper}_FOUND)
+    list(APPEND RB_PYTEST_MISSING_MODULES ${module})
+  endif()
+endforeach()
 
-if(NOT PYTEST_FOUND)
-message(STATUS "Be aware that pytest benchmarks are not enabled (missing pytest & pytest-benchmark dependency). 
-                Please install them using pip and provided requirements.txt")
+if(RB_PYTEST_MISSING_MODULES)
+  set(RB_PYTEST_FOUND FALSE CACHE INTERNAL "" FORCE)
+  string(REPLACE ";" ", " missing_modules "${RB_PYTEST_MISSING_MODULES}")
+  message(WARNING "Python benchmarks are not enabled: ${PYTHON_EXECUTABLE} is missing the module(s) ${missing_modules}.
+                Please install them using pip and the provided requirements.txt")
+else()
+  set(RB_PYTEST_FOUND TRUE CACHE INTERNAL "" FORCE)
 endif()

root/tree/dataframe/RNTupleDSBenchmarks.cxx

@@ -58,7 +58,7 @@ auto Dataframe(DF &frame)
 
 static void BM_RNTupleDS_LHCB(benchmark::State &state)
 {
-   auto ntuple = ROOT::Experimental::RNTupleReader::Open("DecayTree", RB::GetDataDir() + "/B2HHH~none.rc2.ntuple");
+   auto ntuple = ROOT::RNTupleReader::Open("DecayTree", RB::GetDataDir() + "/B2HHH~none.rc2.ntuple");
    const Long64_t nEntries = ntuple->GetNEntries() * (state.range(0) / 100.);
 
    ROOT::RDataFrame df(RB::GetDataDir() + "/B2HHH~none.rc2.ntuple", "DecayTree");

root/tree/tree/CMakeLists.txt

@@ -26,10 +26,10 @@ if(ROOT_root7_FOUND AND rootbench-datafiles AND ROOT_dataframe_FOUND)
     SETUP "${CMAKE_CURRENT_BINARY_DIR}/gen_h1 -o ${RB_DATASETDIR} -c lz4 ${RB_DATASETDIR}/h1dst-lzma.root"
     SETUP "${CMAKE_CURRENT_BINARY_DIR}/gen_h1 -o ${RB_DATASETDIR} -c zstd ${RB_DATASETDIR}/h1dst-lzma.root"
     SETUP "${CMAKE_CURRENT_BINARY_DIR}/gen_h1 -o ${RB_DATASETDIR} -c none ${RB_DATASETDIR}/h1dst-lzma.root"
-    SETUP "hadd -f101 ${RB_DATASETDIR}/h1dst-zlib.root ${RB_DATASETDIR}/h1dst-lzma.root"
-    SETUP "hadd -f404 ${RB_DATASETDIR}/h1dst-lz4.root ${RB_DATASETDIR}/h1dst-lzma.root"
-    SETUP "hadd -f506 ${RB_DATASETDIR}/h1dst-zstd.root ${RB_DATASETDIR}/h1dst-lzma.root"
-    SETUP "hadd -f0 ${RB_DATASETDIR}/h1dst-none.root ${RB_DATASETDIR}/h1dst-lzma.root")
+    SETUP "${RB_HADD_EXECUTABLE} -f101 ${RB_DATASETDIR}/h1dst-zlib.root ${RB_DATASETDIR}/h1dst-lzma.root"
+    SETUP "${RB_HADD_EXECUTABLE} -f404 ${RB_DATASETDIR}/h1dst-lz4.root ${RB_DATASETDIR}/h1dst-lzma.root"
+    SETUP "${RB_HADD_EXECUTABLE} -f506 ${RB_DATASETDIR}/h1dst-zstd.root ${RB_DATASETDIR}/h1dst-lzma.root"
+    SETUP "${RB_HADD_EXECUTABLE} -f0 ${RB_DATASETDIR}/h1dst-none.root ${RB_DATASETDIR}/h1dst-lzma.root")
 endif(ROOT_root7_FOUND AND rootbench-datafiles AND ROOT_dataframe_FOUND)
 
 if(ROOT_root7_FOUND AND rootbench-datafiles)

root/tree/tree/RNTupleH1Benchmarks.cxx

@@ -22,7 +22,7 @@
 
 static void BM_RNTuple_H1(benchmark::State &state, const std::string &comprAlgorithm)
 {
-   using RNTupleReader = ROOT::Experimental::RNTupleReader;
+   using ROOT::RNTupleReader;
    gSystem->Load("./libh1event");
    // Open RNtuple file with RNTuple reader
    std::string path = RB::GetDataDir() + "/h1dst-" + comprAlgorithm + ".ntuple";
@@ -46,7 +46,7 @@ static void BM_RNTuple_H1(benchmark::State &state, const std::string &comprAlgor
    auto njetsView = ntuple->GetCollectionView("event.jets");
    // Check print info (minitest)
    std::ostringstream os;
-   ntuple->PrintInfo(ROOT::Experimental::ENTupleInfo::kSummary, os);
+   ntuple->PrintInfo(ROOT::ENTupleInfo::kSummary, os);
    // Benchmark loop
    for (auto _ : state) {
       // TH1D & TH2D histograms to be filled with data

root/tree/tree/RNTupleLHCBBenchmarks.cxx

@@ -20,7 +20,7 @@ double GetKE(double px, double py, double pz)
 
 static void BM_RNTuple_LHCB(benchmark::State &state)
 {
-   using RNTupleReader = ROOT::Experimental::RNTupleReader;
+   using ROOT::RNTupleReader;
 
    auto ntuple = RNTupleReader::Open("DecayTree", RB::GetDataDir() + "/B2HHH~none.rc2.ntuple");
    auto viewH1IsMuon = ntuple->GetView<int>("H1_isMuon");

root/tree/tree/gen_h1.cxx

@@ -24,10 +24,9 @@
 
 #include "h1event.h"
 
-// Import classes from experimental namespace for the time being
-using RNTupleModel = ROOT::Experimental::RNTupleModel;
-using RNTupleWriter = ROOT::Experimental::RNTupleWriter;
-using RNTupleWriteOptions = ROOT::Experimental::RNTupleWriteOptions;
+using ROOT::RNTupleModel;
+using ROOT::RNTupleWriter;
+using ROOT::RNTupleWriteOptions;
 
 std::string JoinStrings(const std::vector<std::string> &strings, const std::string &joint)
 {
@@ -98,6 +97,10 @@ int main(int argc, char **argv)
       outputFile += std::string("X") + ((bloatFactor < 10) ? "0" : "") + std::to_string(bloatFactor);
    }
    outputFile += std::string("-") + compressionShorthand + ".ntuple";
+   if (!gSystem->AccessPathName(outputFile.c_str())) {
+      std::cout << "Output file " << outputFile << " already exists, nothing to do" << std::endl;
+      return 0;
+   }
    std::cout << "Converting " << JoinStrings(inputFiles, " ") << " --> " << outputFile << std::endl;
 
    TChain *tree = new TChain("h42");