Struct PGRobustNotifier

pub struct PGRobustNotifier<F> { /* private fields */ }

Wraps a PGNotifier and reconnects upon connection loss.

This struct keeps a callback that can be use to spawn new connections to postgres. It’s called upon each time a connection is lost. All the heavy lifting is actually done by the PGNotifier struct.

Implementations

impl<F, S, T> PGRobustNotifier<F>

where F: AsyncFn() -> PGResult<(Client, Connection<S, T>)>, S: AsyncRead + AsyncWrite + Unpin + Send + Sync + 'static, T: AsyncRead + AsyncWrite + Unpin + Send + Sync + 'static,

pub async fn new(connect: F) -> PGResult<Self>

pub async fn client(&mut self) -> PGResult<&PGClient>

Returns the underlying postgres client. If the connection has been closed then it is reconnected.

Note that Client::is_closed is not reliable unless we have a high frequency TPC keepalive, over which we have no control. So we actually attempt a real query each time. Taking inspiration from sqlx, we issue a comment request so that it does not show up in logs. The possibility of the connection being closed right after the ping still exist but should be handled by the caller.

The pool will keep trying to reconnect until it succeeds using exponential backoff with additional jitter.

pub async fn subscribe_notify<CB>( &mut self, channel: impl Into<String>, callback: CB, ) -> PGResult<()>

where CB: Fn(&PGNotify) + Send + Sync + 'static,

pub async fn subscribe_raise( &mut self, callback: impl Fn(&PGRaise) + Send + Sync + 'static, )

pub async fn capture_log(&mut self) -> Option<Vec<PGRaise>>

pub async fn with_captured_log<CB, Data>( &mut self, f: CB, ) -> PGResult<(Data, Vec<PGRaise>)>

where CB: AsyncFnOnce(&PGClient) -> PGResult<Data>,