protected void SetImpl(TKey key, TValue value, TimeSpan timeToLive, long nowTicks)
{
var valueAndExpiryToAdd = _valueAndExpiryPool.Get();
Interlocked.Increment(ref valueAndExpiryToAdd.Version);
var expiryTicks = nowTicks + (long)timeToLive.TotalMilliseconds;
valueAndExpiryToAdd.Value = value;
valueAndExpiryToAdd.ExpiryTicks = expiryTicks;
while (true)
{
var valueFromCache = _values.GetOrAdd(key, valueAndExpiryToAdd);
// If the value was added, we are done
if (valueFromCache == valueAndExpiryToAdd)
{
break;
}
// Otherwise we need to update the value, but because we want to recycle the previous value, we need to
// ensure the update only happens if the value stored is still the one we already have a reference to
if (!_values.TryUpdate(key, valueAndExpiryToAdd, valueFromCache))
{
continue;
}
// The key is already in the expiry queue, so we only need to re-add it if the new value expires before
// the previous value. Otherwise, when the old expiry date is reached the key will be checked and a new
// item will be put in the queue with the new expiry date
var addKeyAndExpiry = expiryTicks < valueFromCache.ExpiryTicks;
_valueAndExpiryPool.Return(valueFromCache);
if (addKeyAndExpiry)
{
break;
}
return;
}
var keyAndExpiry = new KeyAndExpiry(key, expiryTicks);
_keysToBePutIntoExpiryHeapWriter.TryWrite(keyAndExpiry);
}
private void RemoveExpiredKey(KeyAndExpiry keyAndExpiry, long nowTicks)
{
if (!_values.TryGetValue(keyAndExpiry.Key, out var valueAndExpiry))
{
return;
}
if (valueAndExpiry.ExpiryTicks < nowTicks)
{
var kvp = new KeyValuePair <TKey, ValueAndExpiry>(keyAndExpiry.Key, valueAndExpiry);
if (((ICollection <KeyValuePair <TKey, ValueAndExpiry> >)_values).Remove(kvp))
{
_valueAndExpiryPool.Return(valueAndExpiry);
}
}
else
{
_keysToExpireHeap.Add(new KeyAndExpiry(keyAndExpiry.Key, valueAndExpiry.ExpiryTicks));
}
}
