Package org.apache.storm.starter.tools

Class SlotBasedCounter<T>

  • Type Parameters:
    T - The type of those objects we want to count.
    All Implemented Interfaces:
    Serializable
    public final class SlotBasedCounter<T>
extends Object
implements Serializable
    This class provides per-slot counts of the occurrences of objects.

    It can be used, for instance, as a building block for implementing sliding window counting of objects.

    See Also:
    Serialized Form

    • Constructor Detail

      • SlotBasedCounter

        public SlotBasedCounter​(int numSlots)

    • Method Detail

      • incrementCount

        public void incrementCount​(T obj,
                           int slot)

      • getCount

        public long getCount​(T obj,
                     int slot)

      • getCounts

        public Map<T,​Long> getCounts()

      • wipeSlot

        public void wipeSlot​(int slot)
        Reset the slot count of any tracked objects to zero for the given slot.

      • wipeZeros

        public void wipeZeros()
        Remove any object from the counter whose total count is zero (to free up memory).