/** {@inheritDoc} */
@Override
public void onEntryAccessed(boolean rmv, EvictableEntry<K, V> entry) {
if (!rmv) {
if (!entry.isCached()) return;
if (touch(entry)) shrink();
} else {
Node<EvictableEntry<K, V>> node = entry.removeMeta();
if (node != null) {
queue.unlinkx(node);
memSize.add(-entry.size());
}
}
}
/**
* 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;
}
/**
* @param entry Entry to touch.
* @return {@code True} if new node has been added to queue by this call.
*/
private boolean touch(EvictableEntry<K, V> entry) {
Node<EvictableEntry<K, V>> node = entry.meta();
// Entry has not been enqueued yet.
if (node == null) {
while (true) {
node = queue.offerLastx(entry);
if (entry.putMetaIfAbsent(node) != null) {
// Was concurrently added, need to clear it from queue.
queue.unlinkx(node);
// Queue has not been changed.
return false;
} else if (node.item() != null) {
if (!entry.isCached()) {
// Was concurrently evicted, need to clear it from queue.
queue.unlinkx(node);
return false;
}
memSize.add(entry.size());
return true;
}
// If node was unlinked by concurrent shrink() call, we must repeat the whole cycle.
else if (!entry.removeMeta(node)) return false;
}
} else if (queue.unlinkx(node)) {
// Move node to tail.
Node<EvictableEntry<K, V>> newNode = queue.offerLastx(entry);
if (!entry.replaceMeta(node, newNode))
// Was concurrently added, need to clear it from queue.
queue.unlinkx(newNode);
}
// Entry is already in queue.
return false;
}