[fwip]

Main feature is automatic data-sharing between distributions. With torrents, everything is siloed, and data is only exchanged between peers of that torrent. IPFS doesn't care /why/ you're getting information or the link you found it from, just that it can find it by its hash.

Say you distribute "Julie's Webcast Complete Series" and somebody else distributes "Julie's Webcast - Episode 3, with Russian subtitles," peers and seeders from both distributions can share data for the shared content. Similarly, updating a dataset only requires downloading the new data.

This is done automatically, both per-file hashing and (optionally, not sure the current state) of in-file block hashing.

[genpfault]

> Julie's Webcast - Episode 3, with Russian subtitles

> peers and seeders from both distributions can share data for the shared content

So does IPFS have "plugins" for different archive/container formats so it can "see" that the underlying video/audio streams are identical between "Julie's Webcast - Episode 3.mp4" and "Julie's Webcast - Episode 3, with Russian subtitles.mkv"?

Otherwise container stream interleaving will play holy hell with any sort of "dumb" block hashing :(

[fwip]

Last I checked it was dumb. Possibly breaking block boundaries based on a rolling hash.

[sideeffffect]

https://github.com/ipfs/go-ipfs-chunker

> go-ipfs-chunker provides the Splitter interface. IPFS splitters read data from a reader an create "chunks". These chunks are used to build the ipfs DAGs (Merkle Tree) and are the base unit to obtain the sums that ipfs uses to address content.

> The package provides a SizeSplitter which creates chunks of equal size and it is used by default in most cases, and a rabin fingerprint chunker. This chunker will attempt to split data in a way that the resulting blocks are the same when the data has repetitive patterns, thus optimizing the resulting DAGs.

I think they should use the rolling hash based chunking by default

https://github.com/ipfs/go-ipfs-chunker/issues/13

[xj9]

this is an implementation detail of the DHT client. if you have enough cooperating bit torrent clients set up to seed a sparse swarm like IPFS does, you could do the same thing.

which begs the question, why fork the DHT in the first place? there are BEP drafts that cover all of the features that IPFS (and DAT for that matter) bring to the table.

my guess: there isn't a lot of money in making yet another bit torrent client.

[StavrosK]

Yeah but you can't add an episode to the torrent later and have all existing peers seed the old episodes in the new torrent automatically.

[xj9]

you can only do that with IPFS keys that are aliased with IPNS which is equivalent to a BEP-46 mutable DHT key.

http://www.bittorrent.org/beps/bep_0046.html