/// <summary>
/// Trims the LRU cache if needed.
/// </summary>
private void Trim()
{
//
// NB: We can have temporary oversubscription during concurrent accesses because we avoid to enter the write lock
// until absolutely necessary, so _cache.Count can be a dirty read.
//
if (_count >= _maxCapacity)
{
_lock.EnterWriteLock();
try
{
do
{
var entry = _lruList.Last;
if (entry.Key.TryGetTarget(out T key))
{
_cache.Remove(key);
}
LruLinkedList.RemoveLast(ref _lruList);
Interlocked.Decrement(ref _count);
#if DEBUG
_lastEvicted = entry;
_evictionCount++;
#endif
} while (_count >= _maxCapacity);
}
finally
{
_lock.ExitWriteLock();
}
}
}
private void Trim()
{
//
// NB: We can have temporary oversubscription during concurrent accesses because we avoid to enter the write lock
// until absolutely necessary, so _entries.Count can be a dirty read.
//
if (_entries.Count >= _maxCapacity)
{
#if DEBUG
var trimStart = _stopwatch.ElapsedTicks;
#endif
_lock.EnterWriteLock();
try
{
using (var evictionOrder = _ranker.GetEnumerator())
{
while (_entries.Count >= _maxCapacity && evictionOrder.MoveNext())
{
var entry = evictionOrder.Current;
#if DEBUG
_lastEvicted = entry;
#endif
if (entry.Key.TryGetTarget(out T key))
{
_cache.Remove(key);
}
_entries.Remove(entry);
#if DEBUG
_evictionCount++;
#endif
}
}
_entries.RemoveWhere(e => !e.Key.TryGetTarget(out _));
}
finally
{
_lock.ExitWriteLock();
}
#if DEBUG
var trimElapsed = new TimeSpan(_stopwatch.ElapsedTicks - trimStart);
_trimCount++;
_trimElapsed += trimElapsed;
#endif
}
}