celeritas/phys/RootEventSampler.hh

0001 //------------------------------- -*- C++ -*- -------------------------------//
0002 // Copyright Celeritas contributors: see top-level COPYRIGHT file for details
0003 // SPDX-License-Identifier: (Apache-2.0 OR MIT)
0004 //---------------------------------------------------------------------------//
0005 //! \file celeritas/phys/RootEventSampler.hh
0006 //---------------------------------------------------------------------------//
0007 #pragma once
0008
0009 #include <memory>
0010 #include <random>
0011
0012 #include "celeritas/io/EventIOInterface.hh"
0013 #include "celeritas/io/RootEventReader.hh"
0014
0015 namespace celeritas
0016 {
0017 //---------------------------------------------------------------------------//
0018 /*!
0019  * Use \c RootEventReader to load events and sample primaries from them.
0020  */
0021 class RootEventSampler : public EventReaderInterface
0022 {
0023   public:
0024     //!@{
0025     //! \name Type aliases
0026     using SPConstParticles = std::shared_ptr<ParticleParams const>;
0027     using UPRootEventReader = std::unique_ptr<RootEventReader>;
0028     using result_type = std::vector<Primary>;
0029     //!@}
0030
0031   public:
0032     // Construct with input data for RootEventReader and sampling information
0033     RootEventSampler(std::string const& filename,
0034                      SPConstParticles particles,
0035                      size_type num_sampled_events,
0036                      size_type num_merged_events,
0037                      unsigned int seed);
0038
0039     //! Sample primaries for a single event
0040     result_type operator()() final;
0041
0042     //! Get total number of events
0043     size_type num_events() const final { return num_sampled_events_; }
0044
0045   private:
0046     size_type num_sampled_events_;  // Total number of events
0047     size_type num_merged_events_;  // Number of events to be concatenated
0048     UPRootEventReader reader_;
0049     std::mt19937 rng_;
0050     std::uniform_int_distribution<size_type> select_event_;
0051     EventId event_count_{0};
0052 };
0053
0054 //---------------------------------------------------------------------------//
0055 #if !CELERITAS_USE_ROOT
0056 inline RootEventSampler::RootEventSampler(
0057     std::string const&, SPConstParticles, size_type, size_type, unsigned int)
0058 {
0059     CELER_DISCARD(num_sampled_events_);
0060     CELER_DISCARD(num_merged_events_);
0061     CELER_DISCARD(reader_);
0062     CELER_DISCARD(rng_);
0063     CELER_DISCARD(select_event_);
0064     CELER_DISCARD(event_count_);
0065     CELER_NOT_CONFIGURED("ROOT");
0066 }
0067
0068 inline RootEventSampler::result_type RootEventSampler::operator()()
0069 {
0070     CELER_ASSERT_UNREACHABLE();
0071 }
0072 #endif
0073
0074 //---------------------------------------------------------------------------//
0075 }  // namespace celeritas