/**
* Tries to remove one item from queue.
*
* @return number of bytes that was free. {@code -1} if queue is empty.
*/
private int shrink0() {
EvictableEntry<K, V> entry = queue.poll();
if (entry == null) return -1;
int size = 0;
Node<EvictableEntry<K, V>> meta = entry.removeMeta();
if (meta != null) {
size = entry.size();
memSize.add(-size);
if (!entry.evict()) touch(entry);
}
return size;
}
