public static void OnCacheItemRemovedCallback(string key, object value, CacheItemRemovedReason reason)
{
CacheItemUpdateReason updateReason;
SentinelEntry entry = value as SentinelEntry;
switch (reason)
{
case CacheItemRemovedReason.Expired:
updateReason = CacheItemUpdateReason.Expired;
break;
case CacheItemRemovedReason.DependencyChanged:
updateReason = CacheItemUpdateReason.DependencyChanged;
if (entry.ExpensiveObjectDependency.HasChanged)
{
// If the expensiveObject has been removed explicitly by Cache.Remove,
// return from the SentinelEntry removed callback
// thus effectively removing the SentinelEntry from the cache.
return;
}
break;
case CacheItemRemovedReason.Underused:
Debug.Fail("Reason should never be CacheItemRemovedReason.Underused since the entry was inserted as NotRemovable.");
return;
default:
// do nothing if reason is Removed
return;
}
CacheDependency cacheDependency;
DateTime absoluteExpiration;
TimeSpan slidingExpiration;
object expensiveObject;
CacheItemUpdateCallback callback = entry.CacheItemUpdateCallback;
// invoke update callback
try {
callback(entry.Key, updateReason, out expensiveObject, out cacheDependency, out absoluteExpiration, out slidingExpiration);
// Dev10 861163 - Only update the "expensive" object if the user returns a new object and the
// cache dependency hasn't changed. (Inserting with a cache dependency that has already changed will cause recursion.)
if (expensiveObject != null && (cacheDependency == null || !cacheDependency.HasChanged))
{
HttpRuntime.Cache.Insert(entry.Key, expensiveObject, cacheDependency, absoluteExpiration, slidingExpiration, entry.CacheItemUpdateCallback);
}
else
{
HttpRuntime.Cache.Remove(entry.Key);
}
}
catch (Exception e) {
HttpRuntime.Cache.Remove(entry.Key);
try {
WebBaseEvent.RaiseRuntimeError(e, value);
}
catch {
}
}
}