Web (HTTP) Seeding

[olalonde]

WIP (do not merge). See #67
Depends on this PR: https://github.com/feross/bittorrent-swarm/pull/19

I started working on a web seed implementation. The implementation right now is a bit naive (it maps every bittorrent protocol requests to HTTP Range requests) and could probably be optimized.

• downloads from web seeds listed in url-list
• test in web browser
• test what happens when regular peers and web peer

[olalonde]

@feross could you just take a quick look at this and let me know if there's any chance to get this merged? And if I'm heading in the right direction...

[piedshag]

@feross this would be quite handy.

[feross]

@olalonde - you're a hero! Thanks for this PR! Please accept my sincere apologies for the delay in getting this merged. This was a much needed feature.

It only works in node right now, and it only supports BEP19, and the approach isn't very efficient with so many separate requests, but that's all okay for now. We have a starting point to work from now!

[feross]

This is released as 0.51.0.

[olalonde]

Great, @feross. Was starting to wonder if you'd ever take a look at the PR 👍. I'll probably try to improve it in coming days/weeks as I need the functionality for a project I'm working on. I'll try to catch you on IRC if I need some advice.

[feross]

Sounds great!

[samcruz]

Hi there! I'm also interested in support for web seeding. I didn't try this out yet, but from reading the code, it seems this only supports single-file torrents, is that correct? Because if I'm reading BEP19 correctly, one would need to translate from pieces to offsets into specific files for multi-file torrents, which I don't see being done here.

[feross]

@samcruz Yeah, that's not implemented yet.

[batjko]

Does this mean, the testing indicated above hasn't been done before merging?

[jakefb]

Great work @olalonde! I'm trying to test this out but I'm getting an error

When I run the test file download-webseed-torrent.js in node I get:

TAP version 13
# Download using webseed (via .torrent file)

TypeError: Cannot read property 'length' of undefined
    at WebConn.Wire.handshake (/home/jake/webtorrent/node_modules/bittorrent-swarm/node_modules/bittorrent-protocol/index.js:190:39)
    at WebConn.<anonymous> (/home/jake/webtorrent/node_modules/bittorrent-swarm/lib/webconn.js:26:10)
    at WebConn.emit (events.js:106:17)
    at WebConn.Wire._onHandshake (/home/jake/webtorrent/node_modules/bittorrent-swarm/node_modules/bittorrent-protocol/index.js:391:8)
    at WebConn.<anonymous> (/home/jake/webtorrent/node_modules/bittorrent-swarm/node_modules/bittorrent-protocol/index.js:665:12)
    at WebConn.Wire._write (/home/jake/webtorrent/node_modules/bittorrent-swarm/node_modules/bittorrent-protocol/index.js:555:10)
    at doWrite (_stream_writable.js:226:10)
    at writeOrBuffer (_stream_writable.js:216:5)
    at WebConn.Writable.write (_stream_writable.js:183:11)
    at write (_stream_readable.js:585:24)

[feross]

@jakefb Hey! Were you by chance using a magnet link when you got that error? I fixed an issue with that in cb5c9a4 and released it as 0.53.4. Please update and give it another try!