Package de.xima.fc.common.counter

Interface Counter<T extends Comparable<T>>

  • Type Parameters:
    T - The type of value that is counted.
    All Known Subinterfaces:
    Counter.LongCounter
    public interface Counter<T extends Comparable<T>>
    A generic interface for objects that keep a count, using a value from a discrete domain.

    • Method Summary

      All Methods Instance Methods Abstract Methods Default Methods 
      Modifier and Type Method Description
      default void changeBy​(long amount)
      Changes the counter by the specific amount of units.
      default T changeByAndGet​(long amount)
      Changes the counter by the specific amount of units and returns the new value.
      T current()
      Get the current value of the counter.
      default void decrement()
      Decrements the counter by a single unit.
      default T decrementAndGet()
      Decrements the counter by a single unit and returns the new value.
      com.google.common.collect.DiscreteDomain<T> domain()
      Gets the domain discrete domain to which the counter value belongs.
      default T getAndChangeBy​(long amount)
      Gets the current value of the counter, then changes the counter by the specific amount of units.
      default T getAndDecrement()
      Gets the current value of the counter, then decrements the counter by a single unit.
      default T getAndIncrement()
      Gets the current value of the counter, then increments the counter by a single unit.
      default void increment()
      Increments the counter by a single unit.
      default T incrementAndGet()
      Increments the counter by a single unit and returns the new value.
      void set​(T value)
      Sets the counter to a specific value.

    • Method Detail

      • changeBy

        default void changeBy​(long amount)
        Changes the counter by the specific amount of units. A positive amount increments the counter, a negative amount decrements the counter.

        The default implementation of this method is to increment or decrement the counter by repeatedly incrementing or decrementing the counter by a single unit via the domain until the desired amount is reached. Implementations are encouraged to override this method with a more efficient implementation if possible.

        Parameters:
        amount - The amount to change the counter by.

      • changeByAndGet

        default T changeByAndGet​(long amount)
        Changes the counter by the specific amount of units and returns the new value.
        Parameters:
        amount - The amount to change the counter by.
        Returns:
        The new value of the counter after it was changed.

      • current

        T current()
        Get the current value of the counter.
        Returns:
        The current value of the counter.

      • decrement

        default void decrement()
        Decrements the counter by a single unit.

      • decrementAndGet

        default T decrementAndGet()
        Decrements the counter by a single unit and returns the new value.
        Returns:
        The new value of the counter after decrementing.

      • domain

        com.google.common.collect.DiscreteDomain<T> domain()
        Gets the domain discrete domain to which the counter value belongs.
        Returns:
        The domain of the counter value.

      • getAndChangeBy

        default T getAndChangeBy​(long amount)
        Gets the current value of the counter, then changes the counter by the specific amount of units.
        Parameters:
        amount - The amount to change the counter by.
        Returns:
        The previous value of the counter.

      • getAndDecrement

        default T getAndDecrement()
        Gets the current value of the counter, then decrements the counter by a single unit.
        Returns:
        The previous value of the counter.

      • getAndIncrement

        default T getAndIncrement()
        Gets the current value of the counter, then increments the counter by a single unit.
        Returns:
        The previous value of the counter.

      • increment

        default void increment()
        Increments the counter by a single unit.

      • incrementAndGet

        default T incrementAndGet()
        Increments the counter by a single unit and returns the new value.
        Returns:
        The new value of the counter after incrementing.

      • set

        void set​(T value)
        Sets the counter to a specific value.
        Parameters:
        value - The value to set the counter to.