@Nullable @Override protected ReferenceEntry<K, V> computeNext(@Nonnull ReferenceEntry<K, V> previous) { ReferenceEntry<K, V> next = previous.getNextInWriteQueue(); return (next == head) ? null : next; } };
<K, V> void copyWriteEntry(@Nonnull ReferenceEntry<K, V> original, @Nonnull ReferenceEntry<K, V> newEntry) { // TODO(fry): when we link values instead of entries this method can go // away, as can connectWriteOrder, nullifyWriteOrder. newEntry.setWriteTime(original.getWriteTime()); connectWriteOrder(original.getPreviousInWriteQueue(), newEntry); connectWriteOrder(newEntry, original.getNextInWriteQueue()); nullifyWriteOrder(original); } }
@Override public boolean offer(@Nonnull ReferenceEntry<K, V> entry) { // unlink connectWriteOrder(entry.getPreviousInWriteQueue(), entry.getNextInWriteQueue()); // add to tail connectWriteOrder(head.getPreviousInWriteQueue(), entry); connectWriteOrder(entry, head); return true; }
@Override public boolean isEmpty() { return head.getNextInWriteQueue() == head; }
@Override public int size() { int size = 0; for (ReferenceEntry<K, V> e = head.getNextInWriteQueue(); e != head; e = e.getNextInWriteQueue()) { size++; } return size; }
@Override public ReferenceEntry<K, V> peek() { ReferenceEntry<K, V> next = head.getNextInWriteQueue(); return (next == head) ? null : next; }
@Override public void clear() { ReferenceEntry<K, V> e = head.getNextInWriteQueue(); while (e != head) { ReferenceEntry<K, V> next = e.getNextInWriteQueue(); nullifyWriteOrder(e); e = next; } head.setNextInWriteQueue(head); head.setPreviousInWriteQueue(head); }
@Override @SuppressWarnings("unchecked") public boolean contains(Object o) { ReferenceEntry<K, V> e = (ReferenceEntry) o; return e.getNextInWriteQueue() != NullEntry.INSTANCE; }
@Override public ReferenceEntry<K, V> poll() { ReferenceEntry<K, V> next = head.getNextInWriteQueue(); if (next == head) { return null; } remove(next); return next; }
@Override @SuppressWarnings("unchecked") public boolean remove(Object o) { ReferenceEntry<K, V> e = (ReferenceEntry) o; ReferenceEntry<K, V> previous = e.getPreviousInWriteQueue(); ReferenceEntry<K, V> next = e.getNextInWriteQueue(); connectWriteOrder(previous, next); nullifyWriteOrder(e); return next != NullEntry.INSTANCE; }