root/ROOT/RHistFillContext.hxx

0001 /// \file
0002 /// \warning This is part of the %ROOT 7 prototype! It will change without notice. It might trigger earthquakes.
0003 /// Feedback is welcome!
0004
0005 #ifndef ROOT_RHistFillContext
0006 #define ROOT_RHistFillContext
0007
0008 #include "RHist.hxx"
0009 #include "RHistEngine.hxx"
0010 #include "RHistStats.hxx"
0011 #include "RWeight.hxx"
0012
0013 #include <tuple>
0014
0015 namespace ROOT {
0016 namespace Experimental {
0017
0018 // forward declaration for friend declaration
0019 template <typename BinContentType>
0020 class RHistConcurrentFiller;
0021
0022 /**
0023 A context to concurrently fill an RHist.
0024
0025 \sa RHistConcurrentFiller
0026
0027 \warning This is part of the %ROOT 7 prototype! It will change without notice. It might trigger earthquakes.
0028 Feedback is welcome!
0029 */
0030 template <typename BinContentType>
0031 class RHistFillContext final {
0032    friend class RHistConcurrentFiller<BinContentType>;
0033
0034 private:
0035    /// A pointer to the filled histogram
0036    RHist<BinContentType> *fHist = nullptr;
0037
0038    /// Local histogram statistics
0039    RHistStats fStats;
0040
0041    /// \sa RHistConcurrentFiller::CreateFillContent()
0042    explicit RHistFillContext(RHist<BinContentType> &hist) : fHist(&hist), fStats(hist.GetNDimensions())
0043    {
0044       // Propagate disabled dimensions to the local histogram statistics object.
0045       const auto &histStats = hist.GetStats();
0046       for (std::size_t i = 0; i < histStats.GetNDimensions(); i++) {
0047          if (!histStats.IsEnabled(i)) {
0048             fStats.DisableDimension(i);
0049          }
0050       }
0051    }
0052    RHistFillContext(const RHistFillContext &) = delete;
0053    RHistFillContext(RHistFillContext &&) = default;
0054    RHistFillContext &operator=(const RHistFillContext &) = delete;
0055    RHistFillContext &operator=(RHistFillContext &&) = default;
0056
0057 public:
0058    ~RHistFillContext() { Flush(); }
0059
0060    /// Fill an entry into the histogram.
0061    ///
0062    /// If one of the arguments is outside the corresponding axis and flow bins are disabled, the entry will be silently
0063    /// discarded.
0064    ///
0065    /// Throws an exception if the number of arguments does not match the axis configuration, or if an argument cannot be
0066    /// converted for the axis type at run-time.
0067    ///
0068    /// \param[in] args the arguments for each axis
0069    /// \sa RHist::Fill(const std::tuple<A...> &args)
0070    template <typename... A>
0071    void Fill(const std::tuple<A...> &args)
0072    {
0073       fHist->fEngine.FillAtomic(args);
0074       fStats.Fill(args);
0075    }
0076
0077    /// Fill an entry into the histogram with a weight.
0078    ///
0079    /// This overload is not available for integral bin content types (see \ref RHistEngine::SupportsWeightedFilling).
0080    ///
0081    /// If one of the arguments is outside the corresponding axis and flow bins are disabled, the entry will be silently
0082    /// discarded.
0083    ///
0084    /// Throws an exception if the number of arguments does not match the axis configuration, or if an argument cannot be
0085    /// converted for the axis type at run-time.
0086    ///
0087    /// \param[in] args the arguments for each axis
0088    /// \param[in] weight the weight for this entry
0089    /// \sa RHist::Fill(const std::tuple<A...> &args, RWeight weight)
0090    template <typename... A>
0091    void Fill(const std::tuple<A...> &args, RWeight weight)
0092    {
0093       fHist->fEngine.FillAtomic(args, weight);
0094       fStats.Fill(args, weight);
0095    }
0096
0097    /// Fill an entry into the histogram.
0098    ///
0099    /// For weighted filling, pass an RWeight as the last argument. This is not available for integral bin content types
0100    /// (see \ref RHistEngine::SupportsWeightedFilling).
0101    ///
0102    /// If one of the arguments is outside the corresponding axis and flow bins are disabled, the entry will be silently
0103    /// discarded.
0104    ///
0105    /// Throws an exception if the number of arguments does not match the axis configuration, or if an argument cannot be
0106    /// converted for the axis type at run-time.
0107    ///
0108    /// \param[in] args the arguments for each axis
0109    /// \sa RHist::Fill(const A &...args)
0110    template <typename... A>
0111    void Fill(const A &...args)
0112    {
0113       static_assert(sizeof...(A) >= 1, "need at least one argument to Fill");
0114       if constexpr (sizeof...(A) >= 1) {
0115          fHist->fEngine.FillAtomic(args...);
0116          fStats.Fill(args...);
0117       }
0118    }
0119
0120    /// Flush locally accumulated entries to the histogram.
0121    void Flush()
0122    {
0123       fHist->fStats.AddAtomic(fStats);
0124       fStats.Clear();
0125    }
0126 };
0127
0128 } // namespace Experimental
0129 } // namespace ROOT
0130
0131 #endif