private static string ExtractKeyFromExpression <TResult>(Expression <Func <TResult> > func)
{
string key;
MethodCallExpression method = func.Body as MethodCallExpression;
if (method == null)
{
throw new InvalidCachedFuncException("Body must be MethodCallExpression to auto generate a cache key");
}
key = CacheKeyGenerator.GenerateKey(method);
return(key);
}
public static TResult FromCacheOrExecute <TResult>(FujiyBlogDatabase db, Expression <Func <TResult> > func, string key = null, MemoryCacheEntryOptions cacheItemPolicy = null, bool condition = true)
{
string lastDatabaseChangeAtDb = db.LastDatabaseChange;
if (lastDatabaseChangeAtDb != lastDatabaseChange)
{
lastDatabaseChange = lastDatabaseChangeAtDb;
ClearCache();
}
if (!condition)
{
return(func.Compile()());
}
if (func == null)
{
throw new ArgumentNullException("func");
}
if (string.IsNullOrEmpty(key))
{
MethodCallExpression method = func.Body as MethodCallExpression;
if (method == null)
{
throw new InvalidCachedFuncException("Body must be MethodCallExpression to auto generate a cache key");
}
key = CacheKeyGenerator.GenerateKey(method);
}
object returnObject = DefaultCache.Get(key);
if (!(returnObject is TResult))
{
returnObject = func.Compile()();
if (returnObject != null)
{
DefaultCache.Set(key, returnObject, cacheItemPolicy);
}
}
return((TResult)returnObject);
}