How To Update UICollectionView With "reloadData"

Question

I have UICollectionview which has very large content size and the thing is I want to scroll collectionview at the same time while processing collectionview datasource.

Now the problem is while processing and sorting my datasource array; my collectionview is getting affected.

I have questions in my mind :

1. Is there any way to update collection view datasource without having [collectionview reloadData] or without having variation in my collectionview?

It may be not possible but still is there any solution for this?

One Another Question Is - :

I have long content to scroll but if I want to scroll it with smooth animation how to achieve that.

Thanks as usual.