The `closableBasicHost` type needs to be exported so users can access the underlying `BasicHost`

libp2p / go-libp2p

libp2p implementation in Go

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The `closableBasicHost` type needs to be exported so users can access the underlying `BasicHost` #2809

Open aarshkshah1992 opened 1 month ago

aarshkshah1992 commented 1 month ago

Looks like the libp2p.New function was changed to replace the exported BasicHost type with an un-exported closableBasicHost type that wraps a BasicHost

https://github.com/libp2p/go-libp2p/blob/04b2096cb952142073df125a47087fb91eb6b8de/config/config.go#L438

However, there is code in Lotus that depends on being able to access the concrete BasicHost implementation from a libp2p Host and that breaks now.

Please can we export the closableBasicHost type ?

For reference, the Lotus code that breaks is at https://github.com/filecoin-project/lotus/blob/967524aa83852123206715d0f54fd552c7546d5b/node/impl/net/net.go#L138.

aschmahmann commented 1 month ago

@aarshkshah1992 in the specific case you raised can't you get around this by doing an interface check for GetAutoNat rather than a type check?

Maybe the underlying type should be exported, but it seems more likely that it's just a symptom of the more important need of getting access to some of the optional (if common) components of the Host.

aarshkshah1992 commented 1 month ago

@aschmahmann Yeah, you are right. We don't need this change for Lotus anymore. Please feel free to close the issue.

MarcoPolo commented 1 month ago

I'm definitely open to exporting this type, but I'd like to see a better use case. If other folks have use cases or things that broke, please let me know.

It's not as simple as just exporting the type and changing what this function returns because it can now return either a closableBasicHost or a closableRoutedHost.

And generally I want to move away from BasicHost actually being a KitchenSinkHost. I want to move towards services being more pluggable (https://github.com/libp2p/go-libp2p/issues/1993).

MarcoPolo commented 1 month ago

After chatting with @sukunrt for a bit, we think (if needed) we could flip the current style and have basic host call app.Close when it closes. That way we wouldn't need to export a new type and could keep exporting basic host.

Writing this for posterity, but it seems like it may not be needed.