http://labs.carrotsearch.com/hppc.html/hppc: High Performance Primitive Collections. Fundamental data structures (maps, sets, lists, stacks, queues) generated for combinations of object and primitive types to conserve JVM memory and speed up execution. (Carrot Search s.c.)
  • Dawid Weiss
  • Stanisław Osiński 
package com.carrotsearch.hppc;

import java.util.concurrent.atomic.AtomicLong;


Randomized hash order. Does not guarantee deterministic hash ordering between
runs. In fact, it tries hard to avoid such guarantee.

/**
 * Randomized hash order. Does not guarantee deterministic hash ordering between
 * runs. In fact, it tries hard to avoid such guarantee.
 */
public final class RandomizedHashOrderMixer implements HashOrderMixingStrategy {
  public final static RandomizedHashOrderMixer INSTANCE = new RandomizedHashOrderMixer();

  protected final AtomicLong seedMixer;

  public RandomizedHashOrderMixer() {
    this(Containers.randomSeed64());
  }

  public RandomizedHashOrderMixer(long seed) {
    seedMixer = new AtomicLong(seed);
  }

  @Override
  public int newKeyMixer(int newContainerBufferSize) {
    return (int) BitMixer.mix64(seedMixer.incrementAndGet());
  }

  @Override
  public HashOrderMixingStrategy clone() {
    return this;
  }
}