public FixedSizeCacheDict(int maxSize)
{
Max = maxSize;
// List initialization
if (maxSize != 0)
{
BackingListHead = new LRUCacheLinkedListNode <K, V>();
var previousNode = BackingListHead;
var currentNode = BackingListHead;
for (int i = 1; i < maxSize; i++)
{
currentNode = new LRUCacheLinkedListNode <K, V>();
previousNode.Next = currentNode;
currentNode.Previous = previousNode;
previousNode = currentNode;
}
BackingListTail = previousNode;
}
}
private void touch(LRUCacheLinkedListNode <K, V> node)
{
// Stitch the end
if (node.Next == null)
{
BackingListTail = node.Previous;
}
// Stitch the middle
else
{
node.Next.Previous = node.Previous;
}
if (node.Previous != null)
{
node.Previous.Next = node.Next;
}
// Put in front
node.Previous = null;
node.Next = BackingListHead;
BackingListHead.Previous = node;
BackingListHead = node;
}
public void Register(K key, V item)
{
LRUCacheLinkedListNode <K, V> node;
if (Max != 0)
{
// Eject last line of LRU Cache
{
var oldKey = BackingListTail.Key;
if (oldKey != default)
{
FastAccessDict.Remove(oldKey);
}
if (BackingListTail.Value is IDisposable disposable)
{
disposable.Dispose();
}
BackingListTail.Value = default;
}
// Add new line
{
var current = BackingListTail;
current.Key = key;
current.Value = item;
touch(current);
node = current;
}
}
else
{
node = new LRUCacheLinkedListNode <K, V>();
node.Key = key;
node.Value = item;
}
FastAccessDict.Add(key, node);
}