Struct websocket_util::subscribe::Subscription

pub struct Subscription<S, M, I> where
    M: Message,  { /* fields omitted */ }

A subscription associated with a MessageStream that allows for sending and receiving control messages over it.

Notes

• in order for any send operation to resolve, the associated MessageStream stream needs to be polled; that is necessary because this operation expects a control message response and that control message comes through the regular stream.

Implementations

impl<S, M, I> Subscription<S, M, I> where
    S: Sink<I> + Unpin,
    M: Message, 

pub async fn send(
    &mut self,
    item: I
) -> Result<Option<Result<M::ControlMessage, ()>>, S::Error>

Send a message over the internal control channel and wait a control message response.

The method returns the following errors:

• Err(..) when the sink failed to send an item
• Ok(None) when the message stream got closed
• Ok(Some(Err(()))) when message classification reported an error; the actual error still manifests through the message stream

pub async fn read(&mut self) -> Option<Result<M::ControlMessage, ()>>

Wait for a control message to arrive.

Trait Implementations

impl<S: Debug, M: Debug, I: Debug> Debug for Subscription<S, M, I> where
    M: Message,
    M::ControlMessage: Debug, 

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.