Struct Request 

pub struct Request { /* private fields */ }

A subscriber asked for a track this broadcast doesn’t have yet.

Yielded by broadcast::Dynamic::requested_track, or created up front with broadcast::Producer::reserve_track. Subscribers block until the request is resolved: call accept to serve it with a Producer, or reject to fail them. Dropping it without either rejects with Error::Dropped.

Concurrent requests for one name are coalesced, so exactly one of these exists per name at a time.

Implementations

impl Request

pub fn name(&self) -> &str

The requested track name.

pub fn consume(&self) -> Consumer

A Consumer for the eventual track, usable before the request is accepted.

pub fn dynamic(&self) -> Dynamic

Create a Dynamic handle that serves on-demand fetches of uncached groups, before Self::accept is even called. A relay creates one to fetch past groups from upstream while (or instead of) serving a live subscription.

pub fn poll_unused(&self, waiter: &Waiter) -> Poll<()>

Poll for the request becoming unused (every consumer dropped), so a relay can stop serving and drop the request.

pub fn accept(self, info: impl Into<Option<Info>>) -> Producer

Serve the request with the given track, resolving every waiting subscriber.

The name is taken from Self::name; info supplies the remaining knobs (None for the defaults). If the track was already aborted, the returned Producer is inert: writes fail with the abort error, as if it had been aborted immediately after accepting.

pub fn reject(self, err: Error)

Reject the request, waking all waiting subscribers with err.

pub fn subscription(&self) -> Option<Subscription>

The delivery preferences aggregated across everyone waiting on this request, or None if nobody is waiting. Useful for sizing the track before accepting.

pub async fn subscription_changed(&mut self) -> Option<Subscription>

Block until the aggregate subscription changes, yielding None once nobody is waiting.

pub fn poll_subscription_changed( &mut self, waiter: &Waiter, ) -> Poll<Option<Subscription>>

Poll counterpart to subscription_changed.