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//
//
//
//
// ------------------------------------------------------------
//      GEANT 4 class header file
// ------------------------------------------------------------
// Class description:
//
// Class implementing a pool of random numbers filled according
// to specified fixed size (default 1024).

// Author: A.Dotti (SLAC)
// ------------------------------------------------------------
#ifndef G4UNIFORMRANDPOOL_HH
#define G4UNIFORMRANDPOOL_HH

#include "G4Types.hh"
#include "Randomize.hh"

#include <algorithm>
#include <cassert>

#define G4UNIFORMRANDPOOL_DEFAULT_POOLSIZE 1024
#define G4UNIFORMRANDPOOL_TINY_POOLSIZE 128
#define G4UNIFORMRANDPOOL_SMALL_POOLSIZE 256
#define G4UNIFORMRANDPOOL_MEDIUM_POOLSIZE 512
#define G4UNIFORMRANDPOOL_LARGE_POOLSIZE 2048
#define G4UNIFORMRANDPOOL_HUGE_POOLSIZE 8192

class G4UniformRandPool
{
 public:
  G4UniformRandPool();
  explicit G4UniformRandPool(G4int ps);
  ~G4UniformRandPool();

  void Resize(G4int newSize);
  void GetMany(G4double* rnds, G4int howMany);
  inline G4double GetOne();
  inline G4int GetPoolSize() const;

  // These two static methods are used to
  // simulate the calls of CLHEP::HepRandom
  //
  static G4double flat();
  static void flatArray(G4int howmany, G4double* rnds);

 private:
  void Fill(G4int howmany);

 private:
  G4int size{G4UNIFORMRANDPOOL_DEFAULT_POOLSIZE};
  G4double* buffer{nullptr};
  G4int currentIdx{0};
};

inline G4double G4UniformRandPool::GetOne()
{
  // No more available numbers, re-fill
  //
  if(currentIdx >= /*(unsigned int)*/ size)
  {
    Fill(/*(unsigned int)*/ size);
  }

  return buffer[currentIdx++];
}

inline G4int G4UniformRandPool::GetPoolSize() const
{
  return size;
}

#endif