Implement Connection::get_ref to retrieve a reference to the socket

[stormshield-fabs]

This lets users of Connection immutably access the socket they provided.

[jxs]

Hi! And thanks for this, can you give more context on why you need to AsyncRead and AsyncWrite on the internal connection?

[stormshield-fabs]

Hello,
We don't need to use these traits on the internal connection, but we need to directly access attributes that cannot be put behind a synchronization primitive for performance reasons.

Now that I'm re-reading this, maybe the implementations of get_ref should be in different impl blocs without the trait bounds?

[jxs]

We don't need to use these traits on the internal connection, but we need to directly access attributes that cannot be put behind a synchronization primitive for performance reasons.

But how do you access those attributes if you are returning a T?
Can you disclose which attributes are?

[stormshield-fabs]

The precise use case is for metrics: the AsyncRead and AsyncWrite methods on our socket type increment u64s stored in the structure.

let socket = Socket { metric: 0, ... };
let connection = yamux::Connection::new(socket, ...)
// calls to `poll_new_outbound`, `poll_next_inbound`...
let metric = connection.get_ref().unwrap().metric;

[jxs]

The precise use case is for metrics: the AsyncRead and AsyncWrite methods on our socket type increment u64s stored in the structure.

let socket = Socket { metric: 0, ... };
let connection = yamux::Connection::new(socket, ...)
// calls to `poll_new_outbound`, `poll_next_inbound`...
let metric = connection.get_ref().unwrap().metric;

thanks for elaborating, but if you are calling AsyncRead and AsyncWrite on the inner connection you are messing the internal behaviour right? Can you explain what metrics would you like to record? I think it's better to just do as we do in rust-libp2p and offer explicit API's for that

[stormshield-fabs]

We never call AsyncRead nor AsyncWrite on the inner connection, but I see how the proposed patch allows this undesirable behavior.

The metrics are two simple counters for the total written and read bytes on the connection. Can you link me to the explicit APIs you mentioned in rust-libp2p?

[jxs]

The metrics are two simple counters for the total written and read bytes on the connection. Can you link me to the explicit APIs you mentioned in rust-libp2p?

rust-libp2p has its whole metrics crate, which we don't need in this case, we can just expose methods that return the total bytes read and written on Connection which you can then record metrics, wdyt?

[stormshield-fabs]

Yes that would work.

Let's close this PR and I'll submit another with the changes you suggest (except if you'd prefer to take care of it!).

[jxs]

no no, go ahead!
Thanks 🚀