I just got an unexpected problem. I try to use raw...

# ktor

[altavir]

I just got an unexpected problem. I try to use raw sockets from ktor-network to work with home-made TCP-based protocol. And I can't see how I can use Input/Output API with it. It seems like socket IO lives in a completely different world. For example, instead WritableByteChannel I have ByteWriteChannel, which seems to be unrelated. The problem is that I already have ktor-io based code that work with files and it would be very sad to have to re-do it for Ktor sockets. Are there any solutions to this?

[e5l]

Hey @altavir, it looks like you’re trying to use sockets from java.nio.channels . You can use aSocket method to create a socket from ktor-network

[altavir]

I am using

connection = aSocket(ActorSelectorManager(<http://Dispatchers.IO|Dispatchers.IO>))
    .tcp().connect(InetSocketAddress(host, port)).connection()

and trying to use connection

[e5l]

Yep, and the connection has input and output primitives from ktor-io

[altavir]

public class Connection(
    public val socket: Socket,
    public val input: ByteReadChannel,
    public val output: ByteWriteChannel
)

I don't see any way of converting ByteWriteChannel to Output

[altavir]

Those type are similar to Input/Output but seems to be incompatible.

[e5l]

Yep, there are no common blocking adapters on this

[e5l]

The only thing you can do is to use BytePacketBuilder to prepare the message(with buildPacket) and transfer it with writePacket .

[e5l]

BytePacketBuilder is Output

[altavir]

Is it possible to somehow convert them to Input/Output? I can avoid using Ktor and wrap regular java channels, but it seems like a bit of waste (not using ktor to access ktor).

[altavir]

Yeah, I know about builders and I even have my own Binary API which makes it easier. But it does not solve the problem completely. For example streaming read won't work this way

[e5l]

There are no working adapters like this

[altavir]

😞

[e5l]

I’m still not sure that making blocking adapters for streaming cases is a good idea

[altavir]

I am not saying you should. But having single abstraction for input/ouput is very important.

[e5l]

Could you give me a hint on the use cases you have?

[e5l]

I’m not sure that it’s possible to have the same abstraction for suspend and not suspend API

[altavir]

If you have blocking calls they could be called from suspend functions. Not vice versa of course. But it seems to be possbile to have suspending writers implement blocking calls .

[e5l]

I’m not sure that I clearly get it

[e5l]

Could you give me an example of having single abstraction for both with a few methods?

[altavir]

I will see if I have time to implement an Input/Output wrapper on top of ByteRead/WriteChannel. By the way, the name is misleading because it is easy to confuse with WritableByteChannel