feat: circuit v2

[mpetrunic]

closes #1029
Implemented:

• hop protocol + unit tests
• stop protocol + unit tests
• integrated into transport with v1 fallback
• real reservation store
• sending reservations and maintaining relays
• reservation client - establishing reservations on relay

Open questions:

• ~~ what to use as storage for reservation store? ~~
• the best way to do periodic refreshing of reservations?
• is there a way for tagging connections as priority so they don't get removed?

At this point, test/relay/relay.node.js should pass but it doesn't. From my debugging, it breaks at upgrading connection but cannot figure out why (it hangs and then aborts) so I would appreciate somebody with more knowledge of how it works to take a look at it. - fixed

[mxinden]

the best way to do periodic refreshing of reservations?

Not sure whether this is a js-libp2p specific question, or a general question. In case it is of some help, below is the reservation renewal state machine in rust-libp2p:

https://github.com/libp2p/rust-libp2p/blob/fd31d61a7f9ca652e4adb006e2a16a8a5a32ccea/protocols/relay/src/v2/client/handler.rs#L588-L716

[mpetrunic]

the best way to do periodic refreshing of reservations?

Not sure whether this is a js-libp2p specific question, or a general question. In case it is of some help, below is the reservation renewal state machine in rust-libp2p:

https://github.com/libp2p/rust-libp2p/blob/fd31d61a7f9ca652e4adb006e2a16a8a5a32ccea/protocols/relay/src/v2/client/handler.rs#L588-L716

Tnx that is certainly useful. But yeah, seems like it's too part question, as I'm also curious where to put that code inside js-libp2p 😅

[mpetrunic]

@achingbrain Could you help me with test/dialing/resolver.spec.js It seems like it's trying to use libp2p from aegir.js as a relay but in circuiv2 it takes too long to create a reservation with that libp2p and test fails before that happens. Any ideas on how to fix/circumvent that.

I could easily fix it if I could get access to that libp2p variable as I could stub reservation before test starts.

[mpetrunic]

@achingbrain @wemeetagain finally got this in a working state. There is probably a lot of weird stuff as this PR has gone trough numerous merges with a lot of conflicts

[BigLep]

@mpetrunic @achingbrain : what are the next steps for getting this over the line? Is it just about code review?

[mpetrunic]

This is still missing the ability to purge expired reservations but not sure how to architect this as I would need to figure out where to put the reservation store so that it became Startable.

[p-shahi]

closing in favor of #1475