public async Task <bool> Exists(string id)
{
if (MemoryCache.Default.Contains(id))
{
return(true);
}
// the cache does not have the id so lets check the repository
var exists = await repository.Exists(id);
if (exists)
{
// store id in cache as it currently exists
MemoryCache.Default.Add(id, bool.TrueString, null);
}
return(exists);
}