Struct Channel 

pub struct Channel<'a, Req, Resp> { /* private fields */ }

Bidirectional channel: read decoded requests, write framed responses, over the upgraded transport.

Handed to a BidiResponder. Turn-taking by construction — both recv and send take &mut self, so the underlying &mut Upgrade is never aliased. For producers that need to run concurrently with the request loop, spawn a task on the runtime.

The response initial metadata was committed before the upgrade (by the prologue), so there is no way to mutate it here. The trailing metadata, emitted after the loop alongside grpc-status, is still open: write it through response_trailers_mut (the bag was seeded with whatever the prologue set).

Implementations

impl<'a, Req, Resp> Channel<'a, Req, Resp>

pub fn response_trailers_mut(&mut self) -> &mut Headers

The response’s trailing metadata, emitted alongside grpc-status once the loop ends. Seeded with whatever the prologue set; write to it to add trailing metadata (including grpc-status-details-bin error details) from inside the loop.

pub async fn recv(&mut self) -> Option<Result<Req, Status>>

Read the next decoded request. None on clean EOF (client closed the request side); Some(Err(_)) ends the read side.

pub async fn send(&mut self, value: Resp) -> Result<(), Status>

Frame and write one response message.