public bool SetValue(TKey key, TValue value, DateTime expirationTime)
{
if (key == null)
{
throw LogHelper.LogArgumentNullException(nameof(key));
}
if (value == null)
{
throw LogHelper.LogArgumentNullException(nameof(value));
}
// if item already expired, do not add it to the cache if the _removeExpiredValues setting is set to true
if (_removeExpiredValues && expirationTime < DateTime.UtcNow)
{
return(false);
}
// just need to update value and move it to the top
if (_map.TryGetValue(key, out var cacheItem))
{
cacheItem.Value = value;
cacheItem.ExpirationTime = expirationTime;
_eventQueue.Add(() =>
{
_doubleLinkedList.Remove(cacheItem);
_doubleLinkedList.AddFirst(cacheItem);
});
}
else
{
// if cache is at _maxCapacityPercentage, trim it by _compactionPercentage
if ((double)_map.Count / _capacity >= _maxCapacityPercentage)
{
_eventQueue.Add(() =>
{
RemoveLRUs();
});
}
// add the new node
var newCacheItem = new LRUCacheItem <TKey, TValue>(key, value, expirationTime);
_eventQueue.Add(() =>
{
// Add a remove operation in case two threads are trying to add the same value. Only the second remove will succeed in this case.
_doubleLinkedList.Remove(newCacheItem);
_doubleLinkedList.AddFirst(newCacheItem);
});
_map[key] = newCacheItem;
}
return(true);
}
public override bool Equals(object obj)
{
LRUCacheItem <TKey, TValue> item = obj as LRUCacheItem <TKey, TValue>;
return(item != null && Key.Equals(item.Key));
}