/// <summary>
/// BBernard
/// Add or update the cache with the specified cache key and item that will be Lazy Initialized from Lambda function/logic.
/// This method ensures that the item is initialized with full thread safety and that only one thread ever executes the work
/// to initialize the item to be cached -- significantly improving server utilization and performance.
/// </summary>
/// <typeparam name="TKey"></typeparam>
/// <typeparam name="TValue"></typeparam>
/// <param name="key"></param>
/// <param name="fnValueFactory"></param>
/// <param name="cacheItemPolicy"></param>
/// <returns></returns>
public static TValue GetOrAddFromCache <TKey, TValue>(TKey key, Func <TValue> fnValueFactory, CacheItemPolicy cacheItemPolicy)
where TValue : class
{
TValue result = LazyCachePolicy.IsPolicyEnabled(cacheItemPolicy)
? (TValue)_lazyCache.GetOrAddFromCache(key, fnValueFactory, cacheItemPolicy)
: fnValueFactory();
return(result);
}
/// <summary>
/// Helper method to more easily create an Absolute Expiration CacheItemPolicy directly from a Configuration
/// Parameter name that has the TTL Seconds; with Default fallback if it does not exist.
/// </summary>
/// <param name="ttlSecondsConfigKey"></param>
/// <param name="callbackWhenCacheEntryRemoved"></param>
/// <returns></returns>
public static CacheItemPolicy NewAbsoluteExpirationPolicy(string ttlSecondsConfigKey, Action <CacheEntryRemovedArguments> callbackWhenCacheEntryRemoved = null)
{
var timeSpanToLive = LazyCacheConfig.GetCacheTTLFromConfig(ttlSecondsConfigKey, LazyCacheConfig.NeverCacheTTL);
if (timeSpanToLive.TotalMilliseconds > 0)
{
return(LazyCachePolicy.NewAbsoluteExpirationPolicy(timeSpanToLive, callbackWhenCacheEntryRemoved));
}
return(null);
}
/// <summary>
/// Helper method to more easily create an Absolute Expiration CacheItemPolicy directly from a Configuration
/// Parameter names that has the TTL Seconds; this will return the first identified valid configuration key.
/// </summary>
/// <param name="ttlConfigKeysToSearch"></param>
/// <param name="callbackWhenCacheEntryRemoved"></param>
/// <returns></returns>
public static CacheItemPolicy NewAbsoluteExpirationPolicy(string[] ttlConfigKeysToSearch, Action <CacheEntryRemovedArguments> callbackWhenCacheEntryRemoved = null)
{
var timeSpanToLive = LazyCacheConfig.GetCacheTTLFromConfig(ttlConfigKeysToSearch, LazyCacheConfig.NeverCacheTTL);
if (timeSpanToLive.TotalMilliseconds > 0)
{
return(LazyCachePolicy.NewAbsoluteExpirationPolicy(timeSpanToLive, callbackWhenCacheEntryRemoved));
}
//Finally return the cache policy for the first identified valid configuration key.
return(null);
}
/// <summary>
/// BBernard
/// Add or update the cache with the specified cache key and item that will be Lazy Initialized Asynchronously from Lambda function/logic.
/// This method ensures that the item is initialized with full thread safety and that only one thread ever executes the work
/// to initialize the item to be cached -- significantly improving server utilization and performance.
/// </summary>
/// <typeparam name="TKey"></typeparam>
/// <typeparam name="TValue"></typeparam>
/// <param name="key"></param>
/// <param name="fnAsyncValueFactory"></param>
/// <param name="cacheItemPolicy"></param>
/// <returns></returns>
public static async Task <TValue> GetOrAddFromCacheAsync <TKey, TValue>(TKey key, Func <Task <TValue> > fnAsyncValueFactory, CacheItemPolicy cacheItemPolicy)
where TValue : class
{
//Because the underlying cache is set up to store any object and the async coercion isn't as easy as the synchronous,
// we must wrap the original generics typed async factory into a new Func<> that matches the required type.
var wrappedFnValueFactory = new Func <Task <object> >(async() => await fnAsyncValueFactory());
TValue result = LazyCachePolicy.IsPolicyEnabled(cacheItemPolicy)
? (TValue)await _lazyCache.GetOrAddFromCacheAsync(key, wrappedFnValueFactory, cacheItemPolicy)
: await fnAsyncValueFactory();
return(result);
}