// This code implementation is the intellectual property of
// the GEANT4 collaboration.
//
// By copying, distributing or modifying the Program (or any work
// based on the Program) you indicate your acceptance of this statement,
// and all its terms.
//
// $Id: G4VPersistencyManager.hh,v 1.2.4.1 1999/12/07 20:52:58 gunter Exp $
// GEANT4 tag $Name: geant4-02-00 $
//

#ifndef G4VPersistencyManager_h
#define G4VPersistencyManager_h 1

#include "globals.hh"

class G4Event;
class G4Run;
class G4VPhysicalVolume;

// class description:
//
//  This is an abstract base class for persistency management. The user's
// concrete class derived from this class must be a singleton. The user
// must construct the object of his/her concrete persistency manager at
// his/her main().
//  The virtual methods of Store() and Retreive() will be invoked from
// G4RunManager if the persistency manager exists.
//  Even if the user does not use any ODBMS, the user can use this class
// especially for Store() methods. Writing an ASCII file for storing
// event information can be delegated to this class, for example.
//

class G4VPersistencyManager 
{
  public: // with description
      static G4VPersistencyManager* GetPersistencyManager();
      //  Static method to return the pointer to the singleton object.
      // Note that this method does NOT create the singleton object.

  protected:
      G4VPersistencyManager();

  public:
      virtual ~G4VPersistencyManager();

  private: 
      static G4VPersistencyManager * fPersistencyManager;

  public: // with description
      virtual G4bool Store(const G4Event* anEvent)=0;
      virtual G4bool Store(const G4Run* aRun)=0;
      virtual G4bool Store(const G4VPhysicalVolume* theWorld)=0;
      //  Stores G4Event, G4Run, and geometry tree characterized by the world volume.

      virtual G4bool Retrieve(G4Event*& anEvent)=0;
      virtual G4bool Retrieve(G4Run*& aRun)=0;
      virtual G4bool Retrieve(G4VPhysicalVolume*& theWorld)=0;
      //  Restore G4Event, G4Run, and geometry tree characterized by the world volume.

};




#endif

