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//
// G4ElectronOccupancy
//
// Class description:
//
// This class has information of occupation of electrons in atomic orbits.
// GetOccupancy(N) gives the number of electron in N-th orbit
//    For example : Carbon atom should be
//          GetOccupancy(0)      --> 2
//          GetOccupancy(1)      --> 4
//          GetOccupancy(2..7)   --> 0
//
// GetTotalOccupancy() gives the total number of electrons

// Author: Hisaya Kurashige, 17 Aug 1999
// --------------------------------------------------------------------
#ifndef G4ElectronOccupancy_hh
#define G4ElectronOccupancy_hh 1

#include "G4Allocator.hh"
#include "G4ios.hh"
#include "globals.hh"

#include "pwdefs.hh"

class G4ElectronOccupancy
{
  public:
    enum
    {
      MaxSizeOfOrbit = 20
    };

    G4ElectronOccupancy(G4int sizeOrbit = MaxSizeOfOrbit);
    G4ElectronOccupancy(const G4ElectronOccupancy& right);

    virtual ~G4ElectronOccupancy();

    // new/delete operators are overloaded to use G4Allocator
    inline void* operator new(size_t);
    inline void operator delete(void* aElectronOccupancy);

    G4ElectronOccupancy& operator=(const G4ElectronOccupancy& right);
    G4bool operator==(const G4ElectronOccupancy& right) const;
    G4bool operator!=(const G4ElectronOccupancy& right) const;

    inline G4int GetTotalOccupancy() const;
    inline G4int GetOccupancy(G4int orbit) const;
    // The following methods returns
    //     0:  if the orbit(atom) is vacant
    //    >0:  number of electrons in orbit

    G4int AddElectron(G4int orbit, G4int number = 1);
    G4int RemoveElectron(G4int orbit, G4int number = 1);

    inline G4int GetSizeOfOrbit() const;
    void DumpInfo() const;

  private:
    G4int theSizeOfOrbit = 0;
    G4int theTotalOccupancy = 0;
    G4int* theOccupancies = nullptr;
};

extern G4PART_DLL G4Allocator<G4ElectronOccupancy>*& aElectronOccupancyAllocator();

// ------------------------
// Inline methods
// ------------------------

inline void* G4ElectronOccupancy::operator new(size_t)
{
  if (aElectronOccupancyAllocator() == nullptr) {
    aElectronOccupancyAllocator() = new G4Allocator<G4ElectronOccupancy>;
  }
  return (void*)aElectronOccupancyAllocator()->MallocSingle();
}

inline void G4ElectronOccupancy::operator delete(void* aElectronOccupancy)
{
  aElectronOccupancyAllocator()->FreeSingle((G4ElectronOccupancy*)aElectronOccupancy);
}

inline G4int G4ElectronOccupancy::GetSizeOfOrbit() const
{
  return theSizeOfOrbit;
}

inline G4int G4ElectronOccupancy::GetTotalOccupancy() const
{
  return theTotalOccupancy;
}

inline G4int G4ElectronOccupancy::GetOccupancy(G4int orbit) const
{
  G4int value = 0;
  if ((orbit >= 0) && (orbit < theSizeOfOrbit)) {
    value = theOccupancies[orbit];
  }
  return value;
}

#endif