Package org.apache.storm.starter.tools

Class SlotBasedCounter<T>

java.lang.Object
org.apache.storm.starter.tools.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:

  • Constructor Details

    • SlotBasedCounter

      public SlotBasedCounter(int numSlots)

  • Method Details

    • 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).