/// <summary>
/// Gets the user by the id, either from the cache or the database.
/// </summary>
/// <param name="userId">The id of the user to get.</param>
/// <returns>Returns the user info, either from the cache or the database if found, otherwise null.</returns>
public async Task <User> GetByIdAsync(int userId)
{
// Gets the user from cache:
User user = _userCache.Get(userId);
if (user == null)
{
// User not found in cache - so gets from the database:
user = await GetUserByIdFromDatabase(userId);
if (user == null)
{
throw new Exception("The user id was not found in the database.");
}
_userCache.Set(user);
}
return(user);
}
