How to concurrently receive and send data via WebSocketConn? How to process message frames?

[quixoticaxis]

Hello.

I'm probably missing something, but WebSocketConn does not implement Clone while send() and next() use &mut self, so sharing the reference is not an option. How to receive and send data concurrently?

I'm wondering if there is a way to receive and send data frame by frame? It seems that send() and next() operate with Message abstraction, which defines already assembled whole message. Also it's not clear how to send Ping in the middle of a message, or, more realistic, receive Pong in the middle of the message.

[jbr]

You can use WebSocketConn::take_inbound_stream to concurrently send and receive messages.

For non-message-based websockets, it sounds like you might need a different websocket adapter than the one provided by trillium-websockets, or alternatively, a way to drop down to async-tungstenite. Does async_tungstenite::WebSocketStream provide the affordances you need? It should be possible to provide a impl TryFrom<WebSocketConn> for WebSocketStream

[jbr]

It might be worth adding that the inner library (tungstenite) handles ping/pong interactions automatically

[quixoticaxis]

Thank you.
I doubt I would be able to handle the scenario, because only tokio-tungstenite supports the split into separate stream and sink components, the runtime agnostic library does not.

[jbr]

Trillium's WebSocketConn splits the stream and sink internally. When you take_inbound_stream, that's taking the stream side and leaving the sink side on the Conn.

[jbr]

I consider it a design flaw of async-tungstenite's that they chose to offer a single Sink+Stream type that basically requires splitting it to do anything useful. Both trillium's WebSocketConn and tide's WebSocketConnection (which I also authored) have to work around that awkward api

[quixoticaxis]

Oh, I see. Sorry, didn't understand it from the docs. I'll try it later.