public TCacheItem GetOrCreate <TCacheItem>(string key,
Func <string, CacheUpdateCancellationToken, TCacheItem> updateCache,
CacheItemPolicy cachePolicy) where TCacheItem : class
{
key.Requires("key").IsNotNullOrWhiteSpace();
updateCache.Requires("updateCache").IsNotNull();
cachePolicy.Requires("cachePolicy").IsNotNull();
object item;
bool stale;
if (TryGet(key, out item, out stale))
{
if (stale)
{
onAsyncUpdateCache.BeginInvoke(key, updateCache, cachePolicy, null, null);
}
return(item as TCacheItem);
}
var shadowKey = GetShadowKey(key);
var shadowLock = GetLock(shadowKey);
lock (shadowLock)
{
if (TryGet(key, out item))
{
return(item as TCacheItem);
}
item = OnUpdateCache(key, updateCache, cachePolicy);
return(item as TCacheItem);
}
}
public void SetOrUpdateWithoutCreate(string key, object value, CacheItemPolicy policy)
{
key.Requires("key").IsNotNullOrWhiteSpace();
policy.Requires("policy").IsNotNull();
SetOrUpdateWithoutCreate(new CacheItem(key, value), policy);
}
public void SetOrUpdateWithoutCreate(CacheItem item, CacheItemPolicy policy)
{
item.Requires("item").IsNotNull();
policy.Requires("policy").IsNotNull();
var shadowKey = GetShadowKey(item.Key);
lock (GetLock(item.Key))
{
storeCache.Set(item.Key, item.Value, ObjectCache.InfiniteAbsoluteExpiration);
shadowCache.Set(shadowKey, DummyShadowObject, policy);
}
}
internal CacheUpdateCancellationToken(CacheItemPolicy cacheItemPolicy)
{
cacheItemPolicy.Requires("cacheItemPolicy").IsNotNull();
this.CacheItemPolicy = cacheItemPolicy;
}