Is there a way to split/buffer a ByteReadChannel? My use case is downloading a file from a http URL on GET request and then streaming it to the client as as well as a local file.

Hi @Quy D X Nguyen, it looks like: https://api.ktor.io/1.3.2/io.ktor.util/split.html

So this code does not respond, but the commented line works fine.

get("/") {
	call.respondBytesWriter(ContentType.defaultForFileExtension(".jpg")) {
		client.get<HttpStatement>("<https://chandra.harvard.edu/photo/2017/arp299/arp299_4k.jpg>").execute { response: HttpResponse ->
			//response.receive<ByteReadChannel>().joinTo(this, false)
			val (channelResponse, channelFile) = response.receive<ByteReadChannel>().split(this@embeddedServer)
			
			channelFile.joinTo(File("image").writeChannel(), true)
			channelResponse.joinTo(this, false)
		}
	}
}

Could you move one of your consumers to

launch { }

? The channels should be consumed simultaneously.

I'm not too familiar with coroutines, so I don't know where you want this

launch{}

call