Torrent padding files

Question

Did anyone created padding files for torrent? How many clients use this stuff nowadays? Is "padding files" comprehensive?

I didn't found this feature in new clients such as ctorrent,ttorent, trasmission etc.

Do you have implementaions of this feature or some theory or history about this?

I will be appreciated for answers!

Solution

Padding files are created by BitComet. Their use

ensures that no two data files in a multi-file torrent occupy the same BitTorrent "piece".

They are supposed to be hidden or invisible to BitComet users but can actually harm the performance in other clients because these files are transferred, which takes up bandwidth.

You can read more about it here.

Comments

[Alex Rezistorman]

So, as I understood it's not mandatory to use it. Is libtorrent require this files or it's just legacy?

[MC10]

I don't have experience with libtorrent. It probably depends on the client. The only thing I know is that BitComet creates the files. You don't need them.

[Pui Ho Lam]

Actually, you need the null data so that when you do selection download, you don't end up still downloading part of the optional file.