Counter.h

// -*- indent-tabs-mode: nil -*-

// Counter.h

#ifndef __Counter__
#define __Counter__

#include <glibmm/timeval.h>

namespace Arc {

  extern const Glib::TimeVal ETERNAL;

  extern const Glib::TimeVal HISTORIC;



  // Some forward declarations.
  class Counter;
  class CounterTicket;
  class ExpirationReminder;




  class Counter {

  protected:


    typedef unsigned long long int IDType;


    Counter();

  public:


    virtual ~Counter();


    virtual int getLimit() = 0;


    virtual int setLimit(int newLimit) = 0;


    virtual int changeLimit(int amount) = 0;


    virtual int getExcess() = 0;


    virtual int setExcess(int newExcess) = 0;


    virtual int changeExcess(int amount) = 0;


    virtual int getValue() = 0;


    virtual CounterTicket reserve(int amount = 1,
                                  Glib::TimeVal duration = ETERNAL,
                                  bool prioritized = false,
                                  Glib::TimeVal timeOut = ETERNAL) = 0;

  protected:


    virtual void cancel(IDType reservationID) = 0;


    virtual void extend(IDType& reservationID,
                        Glib::TimeVal& expiryTime,
                        Glib::TimeVal duration = ETERNAL) = 0;


    Glib::TimeVal getCurrentTime();


    Glib::TimeVal getExpiryTime(Glib::TimeVal duration);


    CounterTicket getCounterTicket(Counter::IDType reservationID,
                                   Glib::TimeVal expiryTime,
                                   Counter *counter);


    ExpirationReminder getExpirationReminder(Glib::TimeVal expTime,
                                             Counter::IDType resID);
  private:


    Counter(const Counter& unique);


    void operator=(const Counter& unique);

    friend class CounterTicket;

    friend class ExpirationReminder;

  };




  class CounterTicket {

  public:


    CounterTicket();


    bool isValid();


    void extend(Glib::TimeVal duration);


    void cancel();

  private:


    CounterTicket(Counter::IDType reservationID,
                  Glib::TimeVal expiryTime,
                  Counter *counter);

    Counter::IDType reservationID;

    Glib::TimeVal expiryTime;

    Counter *counter;

    friend class Counter;

  };




  class ExpirationReminder {

  public:


    bool operator<(const ExpirationReminder& other) const;


    Glib::TimeVal getExpiryTime() const;


    Counter::IDType getReservationID() const;

  private:


    ExpirationReminder(Glib::TimeVal expiryTime,
                       Counter::IDType reservationID);

    Glib::TimeVal expiryTime;

    Counter::IDType reservationID;

    friend class Counter;

  };

}

#endif