[ktor-network] <@U4CP1J0QP> Hi, I am starting to t...

# ktor

[Didier Villevalois]

[ktor-network] @e5l Hi, I am starting to think about the implementation for the support of unix domain sockets (aka ipc sockets) in ktor-network as I proposed before. After delving in the code, I already have a few questions:

1. Should I first open a ticket on YouTrack before submitting a PR?
2. It seems that I would not have a lot to do for the native part (did not look at the Jvm part yet) because the posix API is the same to use IPC sockets modulo some constants (mainly the address family, AF_UNIX instead of AF_INET). However, I think I would need to do some (problematic?) refactoring first.
◦ AConnectedSocket and ABoundSocket both use NetworkAddress for their remoteAddress and localAddress which is problematic, because too restrictive. Presumably, I would have to introduce some super-class to NetworkAddress and another sibling to NetworkAddress (say UnixAddress). This refactoring could ripple a lot.
◦ Rename TCPSocketNative to ByteStreamSocketNative as its implementation would be used as is for both TCP byte-stream sockets and IPC byte-stream sockets. (Same for TCPServerSocketNative )
◦ Adapt the first two lines of both connect() and bind() (in ConnectUtilsNative.kt) to also handle the UnixAddress. The rest of the code would (more or less) stay as is.
That's all for now. I am quite ready to jump on the wagon, as there won't be much work to do (and I desperately need this 🤪). Please guide me on how I should proceed. Thanks in advance.

[e5l]

Hey @Didier Villevalois, thanks for the questions:
1. There is a ticket on YT
2. It should be OK, the only things to be careful is Public API surface.
Feel free to ping me if you have any questions 🙂

[Didier Villevalois]

OK, found the issue: https://youtrack.jetbrains.com/issue/KTOR-781.

When you say "public API surface", you mean Ktor's own API right ? Because everything in ktor-network and ktor-utils (NetworkAddress is there) is internal, am I wrong?

[Didier Villevalois]

@e5l So it seems to me that the only public use of NetworkAddress is in the return type of ProxyConfig.resolveAddress() . ProxyConfig is public and used as the type of the proxy attribute of HttpClientEngineConfig .

Ideally, I would like to rename NetworkAddress as InetSocketAddress in order to have the hierarchy:
• SocketAddress
◦ InetSocketAddress
◦ UnixSocketAddress
Do you think that would be a pain point? We could have a typealias from NetworkAddress to InetSocketAddress. (Note that NetworkAddress on jvm is already a typealias to SocketAddress .)

[Didier Villevalois]

@e5l I've got a bigger problem. java.net.UnixDomainSocketAddress is only from java 16. Ktor targets an older java. I don't think there is a way to tell Kotlin to ignore if the actual class does not exist.

I would have to make a parallel hierarchy (without actual typealias) and test if the feature exist dynamically. Is that the way to go ?