Sequential Downloads

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Can you add support for sequential downloading.

[anacrolix]

Do you mean for cmd/torrent? In the library, just open a reader on the file/torrent you want, and read in the order you want.

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I can use the reader to read in order, but that doesn't ensure the torrent downloads in order. I understand BitTorrent is not optimal to download the data in order, but I wish to use it for video streaming.

[anacrolix]

I use the torrent Client myself for video streaming, its piece prioritization is designed to ensure that data is optimized toward satisfying sequential reads from the torrent.Reader type. For example any time the Reader is blocked on a Read, the piece is selected for all current peers. The next piece is also chosen next, only after the next 2 pieces are available does it start to split the peers across the Readahead window set on the Reader. (It's currently 5MB by default.) If you io.Copy(ioutil.Discard, someReader), it will consume the data so quickly it will probably download every single piece in order as it will always be blocked on the next unavailable piece.

Just to check, be sure to stream the data to your player from the torrent.Reader. Don't access the filesystem directly as I've seen people do. When accessing the filesystem, the player won't know that EOF isn't corruption, as it isn't synced with the torrent client as it will be if you feed it from the torrent.Reader yourself. See cmd/torrentfs if you want to go that route.

[swrap]

Thanks so much! I will check this out and write back about my findings :) Really appreciate the quick response (sorry I took awhile) and love the library!

[antonsoroko]

@anacrolix
Hi.

For example any time the Reader is blocked on a Read, the piece is selected for all current peers. The next piece is also chosen next, only after the next 2 pieces are available does it start to split the peers across the Readahead window set on the Reader.

Is it possible to somehow force the library to download all the pieces sequentially?
As it done in desktop torrent clients(e.g. qbittorent, piece by piece, maybe with some minor deviations).
Thank you!

[anacrolix]

@antonsoroko not currently