RandomNumberGenerator.h

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#ifndef FWCore_Utilities_RandomNumberGenerator_h
#define FWCore_Utilities_RandomNumberGenerator_h

#include <cstdint>
#include <iosfwd>
#include <memory>
#include <vector>

class RandomEngineState;

namespace CLHEP {
  class HepRandomEngine;
}

namespace edm {

  class ConsumesCollector;
  class Event;
  class LuminosityBlock;
  class LuminosityBlockIndex;
  class StreamID;

  class RandomNumberGenerator {
  public:
    RandomNumberGenerator() {}
    RandomNumberGenerator(RandomNumberGenerator const&) = delete;
    RandomNumberGenerator const& operator=(RandomNumberGenerator const&) = delete;
    virtual ~RandomNumberGenerator();


    virtual CLHEP::HepRandomEngine& getEngine(StreamID const&) = 0;

    virtual CLHEP::HepRandomEngine& getEngine(LuminosityBlockIndex const&) = 0;

    virtual std::unique_ptr<CLHEP::HepRandomEngine> cloneEngine(LuminosityBlockIndex const&) = 0;

    virtual std::uint32_t mySeed() const = 0;

    // The following functions should not be used by general users.  They
    // should only be called by Framework code designed to work with the
    // service while it is saving the engine states or restoring them.
    // The first two are called by the EventProcessor at special times.
    // The next two are called by a dedicated producer module (RandomEngineStateProducer).

    virtual void preBeginLumi(LuminosityBlock const& lumi) = 0;
    virtual void postEventRead(Event const& event) = 0;

    virtual void setLumiCache(LuminosityBlockIndex, std::vector<RandomEngineState> const& iStates) = 0;
    virtual void setEventCache(StreamID, std::vector<RandomEngineState> const& iStates) = 0;

    virtual std::vector<RandomEngineState> const& getEventCache(StreamID const&) const = 0;
    virtual std::vector<RandomEngineState> const& getLumiCache(LuminosityBlockIndex const&) const = 0;

    virtual void consumes(ConsumesCollector&& iC) const = 0;

    virtual void print(std::ostream& os) const = 0;
  };
}  // namespace edm
#endif