public void Insert(CacheEntry head)
{
Prev = head;
Next = head.Next;
Next.Prev = this;
Prev.Next = this;
}
public Cache(int size)
{
_size = size;
_map = new Dictionary<object, CacheEntry>(size);
_head = new CacheEntry(null, null);
_tail = new CacheEntry(null, null);
_head.Next = _tail;
_tail.Prev = _head;
}
public void Add(object key, object value)
{
if (_ejector == null)
{
throw new InvalidOperationException("You must set the Ejector strategy in order to use the cache.");
}
CacheEntry entry;
if (_map.TryGetValue(key, out entry))
{
entry.Remove();
entry.Insert(_head);
entry.Value = value;
}
else
{
entry = new CacheEntry(key, value);
_map.Add(key, entry);
entry.Insert(_head);
if (_map.Count > _size)
{
CacheEntry victim = _ejector.GetEjectionVictim();
_map.Remove(victim.Key);
victim.Remove();
}
}
}
