public int getSizeForEviction() {
    EvictionAttributes ea = getAttributes().getEvictionAttributes();
    if (ea == null) {
      return 0;
    }
    EvictionAlgorithm algo = ea.getAlgorithm();
    if (!algo.isLRUHeap()) {
      return 0;
    }
    EvictionAction action = ea.getAction();
    return action.isLocalDestroy() ? getRegionMap().sizeInVM() : (int) getNumEntriesInVM();
  }
Increments the current number of entries whose value has been overflowed to disk by this
bucket,by a given amount.
geode-core/src/main/java/org/apache/geode/internal/cache/BucketRegion.java