/** {@inheritDoc} */
@Override
protected Collection<E> dequeue0(int cnt) {
WindowHolder tup = ref.get();
AtomicInteger size = tup.size();
Collection<T> evts = tup.collection();
Collection<E> resCol = new ArrayList<>(cnt);
while (true) {
int curSize = size.get();
if (curSize > 0) {
if (size.compareAndSet(curSize, curSize - 1)) {
E res = pollInternal(evts, tup.set());
if (res != null) {
resCol.add(res);
if (resCol.size() >= cnt) return resCol;
} else {
size.incrementAndGet();
return resCol;
}
}
} else return resCol;
}
}
/** @param evts Events to add. */
private void addAll(Collection<E> evts) {
WindowHolder tup = ref.get();
int cnt = addAllInternal(evts, tup.collection(), tup.set());
tup.size().addAndGet(cnt);
}
/**
* Poll evicted internal implementation.
*
* @return Evicted element.
*/
@Nullable
private E pollEvictedInternal() {
WindowHolder tup = ref.get();
AtomicInteger size = tup.size();
while (true) {
int curSize = size.get();
if (curSize > maxSize) {
if (size.compareAndSet(curSize, curSize - 1)) {
E evt = pollInternal(tup.collection(), tup.set());
if (evt != null) return evt;
else {
// No actual events in queue, it means that other thread is just adding event.
// return null as it is a concurrent add call.
size.incrementAndGet();
return null;
}
}
} else return null;
}
}
/**
* Get underlying collection.
*
* @return Collection.
*/
@SuppressWarnings("ConstantConditions")
protected Collection<T> collection() {
return ref.get().get1();
}
/** Checks window consistency. Used for testing. */
void consistencyCheck() {
WindowHolder win = ref.get();
consistencyCheck(win.collection(), win.set(), win.size());
}
/** @param evt Event to add. */
private void add(E evt) {
WindowHolder tup = ref.get();
if (addInternal(evt, tup.collection(), tup.set())) tup.size().incrementAndGet();
}
/** {@inheritDoc} */
@Override
protected void reset0() {
ref.set(
new WindowHolder(
newCollection(), unique ? new GridConcurrentHashSet<E>() : null, new AtomicInteger()));
}
/** {@inheritDoc} */
@Override
protected GridStreamerWindowIterator<E> iterator0() {
WindowHolder win = ref.get();
return iteratorInternal(win.collection(), win.set(), win.size());
}
/** {@inheritDoc} */
@Override
public int size() {
int size = ref.get().size().get();
return size > 0 ? size : 0;
}