MasterRandomGenerator.hpp

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#ifndef _MASTERRANDOMGENERATOR_HPP
#define _MASTERRANDOMGENERATOR_HPP

/// \file MasterRandomGenerator.hpp
///
/// \brief Master random generator, used to start streams
///
/// This random generator is expected to be used few times, so we
/// don't care using a slow one not supporting big skip

#include <random/TrueRandomGenerator.hpp>
#include <Serialize.hpp>

namespace SUNphi
{
  /// Inner generator used
  using _MasterRandomGenerator=
    std::mt19937_64;

  /// Master random generator
  class MasterRandomGenerator :
    public SerializableClass<MasterRandomGenerator>,
    public _MasterRandomGenerator
  {
    /// Number of seeds needed to initialize the state
    static constexpr int nSeeds=
      _MasterRandomGenerator::state_size;

    /// Seed state
    SERIALIZABLE_SCALAR_WITH_TAG(std::vector<uint64_t>,_seeds,"Seeds",nSeeds);

    /// Constant access to the seeds
    const std::vector<uint64_t>& seeds=
      _seeds;

    /// Base random generator
    using Base=
      _MasterRandomGenerator;

  public:

    LIST_SERIALIZABLE_MEMBERS(_seeds);

    /// Reset the number generator to the initial state
    void reset()
    {
      // Prepares a seed sequence to initialize
      std::seed_seq dseeds(seeds.begin(),seeds.end());

      this->seed(dseeds);
    }

    /// Skip n elements
    void skip(const int n)
    {
      for(int i=0;i<n;i++)
    (*this)();
    }

    /// Fills _seeds using the true random generator
    MasterRandomGenerator()
    {
      std::generate(_seeds().begin(),_seeds().end(),std::ref(trueRandomGenerator));

      reset();
    }
  };
}

#endif