Module swim.util
Package swim.util

Class HashGenCacheSet<T>

java.lang.Object
swim.util.HashGenCacheSet<T>
public class HashGenCacheSet<T> extends Object
A hashed generational cache set discards the least recently used value with the worst hit rate per hash bucket. HashGenCacheSet is a concurrent and lock-free LRFU cache, with O(1) access time.

Maintaining four "generations" of cached values per hash bucket, the cache discards from the younger generations based on least recent usage, and promotes younger generations to older generations based on most frequent usage. Cache misses count as negative usage of the older generations, biasing the cache against least recently used values with poor hit rates.

The cache soft references the older generations, and weak references the younger generations; the garbage collector can reclaim the entire cache, but will preferentially wipe the younger cache generations before the older cache generations.

  • Constructor Details

    • HashGenCacheSet

      public HashGenCacheSet(int size)

  • Method Details

    • put

      public T put(T value)

    • weaken

      public boolean weaken(T value)

    • remove

      public boolean remove(T value)

    • clear

      public void clear()

    • hitRatio

      public double hitRatio()