Struct PgNotifyBus 

pub struct PgNotifyBus { /* private fields */ }

Process-wide PostgreSQL LISTEN multiplexer.

Create one at runtime startup, register all channels up front, then call run in a background task. Subsystems obtain a broadcast::Receiver<String> via subscribe.

Implementations

impl PgNotifyBus

pub fn new(pool: PgPool, channels: &[&str]) -> Self

Create a new notify bus for the given channels.

Each channel gets a broadcast::channel(256) so subscribers can lag slightly without losing messages. The bus does not start listening until run is called.

pub fn subscribe(&self, channel: &str) -> Option<Receiver<String>>

Subscribe to notifications on channel.

Returns None if channel was not registered at construction time. The returned receiver yields the raw NOTIFY payload string.

pub fn channels(&self) -> Vec<&str>

Returns the set of channel names this bus is configured for.

pub fn subscribe_reconnects(&self) -> Receiver<u64>

Subscribe to reconnect events.

The returned receiver’s value is bumped once per successful (re)connect of the underlying PgListener. The initial connect publishes 1; subsequent reconnects publish 2, 3, etc. Subscribers that want to trigger gap recovery on reconnect should:

1. Call subscribe_reconnects() and snapshot the current generation via *rx.borrow().
2. In their main loop, select! on rx.changed() alongside their payload recv().
3. On a change, compare *rx.borrow() to the snapshot and only treat it as a reconnect if it is strictly greater than the snapshot — this filters the first-boot connect for subscribers that attach before run() succeeds.

pub async fn run(&self, shutdown: Receiver<bool>)

Run the listener loop until shutdown fires.

This must be spawned as a background task. It owns the single PgListener connection, reconnects on failure, and fans out every received notification to the matching broadcast channel.