public object GetCacheItem(string cacheKey, Func <object> getCacheItem, TimeSpan?timeout, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
{
// see notes in HttpRuntimeCacheProvider
Lazy <object> result;
using (var lck = new UpgradeableReadLock(_locker))
{
result = MemoryCache.Get(cacheKey) as Lazy <object>;
if (result == null || DictionaryCacheProviderBase.GetSafeLazyValue(result, true) == null) // get non-created as NonCreatedValue & exceptions as null
{
result = DictionaryCacheProviderBase.GetSafeLazy(getCacheItem);
var policy = GetPolicy(timeout, isSliding, removedCallback, dependentFiles);
lck.UpgradeToWriteLock();
//NOTE: This does an add or update
MemoryCache.Set(cacheKey, result, policy);
}
}
//return result.Value;
var value = result.Value; // will not throw (safe lazy)
var eh = value as DictionaryCacheProviderBase.ExceptionHolder;
if (eh != null)
{
throw eh.Exception; // throw once!
}
return(value);
}
public void InsertCacheItem(string cacheKey, Func <object> getCacheItem, TimeSpan?timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
{
InnerProvider.InsertCacheItem(cacheKey, () =>
{
var result = DictionaryCacheProviderBase.GetSafeLazy(getCacheItem);
var value = result.Value; // force evaluation now - this may throw if cacheItem throws, and then nothing goes into cache
if (value == null)
{
return(null); // do not store null values (backward compat)
}
return(CheckCloneableAndTracksChanges(value));
}, timeout, isSliding, priority, removedCallback, dependentFiles);
}
public object GetCacheItem(string cacheKey, Func <object> getCacheItem)
{
var cached = InnerProvider.GetCacheItem(cacheKey, () =>
{
var result = DictionaryCacheProviderBase.GetSafeLazy(getCacheItem);
var value = result.Value; // force evaluation now - this may throw if cacheItem throws, and then nothing goes into cache
if (value == null)
{
return(null); // do not store null values (backward compat)
}
return(CheckCloneableAndTracksChanges(value));
});
return(CheckCloneableAndTracksChanges(cached));
}
public void InsertCacheItem(string cacheKey, Func <object> getCacheItem, TimeSpan?timeout = null, bool isSliding = false, CacheItemPriority priority = CacheItemPriority.Normal, CacheItemRemovedCallback removedCallback = null, string[] dependentFiles = null)
{
// NOTE - here also we must insert a Lazy<object> but we can evaluate it right now
// and make sure we don't store a null value.
var result = DictionaryCacheProviderBase.GetSafeLazy(getCacheItem);
var value = result.Value; // force evaluation now
if (value == null)
{
return; // do not store null values (backward compat)
}
var policy = GetPolicy(timeout, isSliding, removedCallback, dependentFiles);
//NOTE: This does an add or update
MemoryCache.Set(cacheKey, result, policy);
}
public object GetCacheItem(string cacheKey, Func <object> getCacheItem)
{
var result = _items.GetOrAdd(cacheKey, k => DictionaryCacheProviderBase.GetSafeLazy(getCacheItem));
var value = result.Value; // will not throw (safe lazy)
if (!(value is DictionaryCacheProviderBase.ExceptionHolder eh))
{
return(value);
}
// and... it's in the cache anyway - so contrary to other cache providers,
// which would trick with GetSafeLazyValue, we need to remove by ourselves,
// in order NOT to cache exceptions
_items.TryRemove(cacheKey, out result);
eh.Exception.Throw(); // throw once!
return(null); // never reached
}