// If duplicates are allowed, this IdentityHashMap will record the final Entry for each
    // duplicated key. We will use this final Entry to overwrite earlier slots in the entries array
    // that have the same key. Then a second pass will remove all but the first of the slots that
    // have this Entry. The value in the map becomes false when this first entry has been copied, so
    // we know not to copy the remaining ones.

     */
    private static <K, V> Entry<K, V> @Nullable [] lastEntryForEachKey(
        Entry<K, V>[] entries, int size) {
      Set<K> seen = new HashSet<>();
      BitSet dups = new BitSet(); // slots that are overridden by a later duplicate key
      for (int i = size - 1; i >= 0; i--) {
        if (!seen.add(entries[i].getKey())) {
          dups.set(i);
        }
      }
      if (dups.isEmpty()) {

    }

    private @Nullable Object[] lastEntryForEachKey(
        @Nullable Object[] localAlternatingKeysAndValues, int size) {
      Set<Object> seenKeys = new HashSet<>();
      BitSet dups = new BitSet(); // slots that are overridden by a later duplicate key
      for (int i = size - 1; i >= 0; i--) {
        Object key = requireNonNull(localAlternatingKeysAndValues[2 * i]);
        if (!seenKeys.add(key)) {
          dups.set(i);

    void cacheCapacityAndRetrievalOrder() {
        BufferCacheImpl impl = new BufferCacheImpl(2, 3);
        byte[] a = new byte[1];
        byte[] c = new byte[2];
        byte[] d = new byte[4];

        impl.releaseBuffer(a); // goes to slot 0
        impl.releaseBuffer(c); // goes to slot 1
        impl.releaseBuffer(d); // dropped (cache full)

    // Add values up to 40. This covers cases like "square of a prime" and such.
    for (int i = 1; i <= 40; i++) {
      intValues.add(i);
    }
    // Now add values near 2^N for lots of values of N.
    for (int exponent : asList(2, 3, 4, 9, 15, 16, 17, 24, 25, 30)) {
      int x = 1 << exponent;
      intValues.add(x, x + 1, x - 1);
    }

  /** Used for concurrent threads reading the list for the first time. */
  private val readCompleteLatch = CountDownLatch(1)

  // The lists are held as a large array of UTF-8 bytes. This is to avoid allocating lots of strings
  // that will likely never be used. Each rule is separated by '\n'. Please see the
  // PublicSuffixListGenerator class for how these lists are generated.
  // Guarded by this.
  override lateinit var bytes: ByteString

    /*
     * TODO: cpovirk - Pre-size the HashMap based on the number of enum values? (But *not* based on
     * the number of entries in the map, as that makes it easy for hostile inputs to trigger lots of
     * allocation—not that any program should be deserializing hostile inputs to begin with!)
     */
    setDelegates(new EnumMap<K, V>(keyTypeOrObjectUnderJ2cl), new HashMap<V, K>());

// operation succeeded.
func (h *healSequence) pushHealResultItem(r madmin.HealResultItem) error {
	// start a timer to keep an upper time limit to find an empty
	// slot to add the given heal result - if no slot is found it
	// means that the server is holding the maximum amount of
	// heal-results in memory and the client has not consumed it
	// for too long.

	// at any given point in time. This allows different buckets to be scanned
	// in different order per erasure set, this wider spread is needed when
	// there are lots of buckets with different order of objects in them.
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	permutes := r.Perm(len(buckets))
	// Add new buckets first
	for _, idx := range permutes {
		b := buckets[idx]

    return new ExpiringMemoizingSupplier<>(delegate, toNanosSaturated(duration));
  }

  @VisibleForTesting
  @SuppressWarnings("GoodTime") // lots of violations
  static final class ExpiringMemoizingSupplier<T extends @Nullable Object>
      implements Supplier<T>, Serializable {
    private transient Object lock = new Object();

    final Supplier<T> delegate;