Struct PGNotifier

pub struct PGNotifier {
    pub client: Client,
    /* private fields */
}

Forwards PostgreSQL NOTIFY and RAISE commands to subscribers.

Fields

client: Client

Implementations

impl PGNotifier

pub fn spawn<S, T>(client: PGClient, conn: PGConnection<S, T>) -> Self

where S: AsyncRead + AsyncWrite + Unpin + Send + Sync + 'static, T: AsyncRead + AsyncWrite + Unpin + Send + Sync + 'static,

Spawns a new postgres client/connection pair.

pub async fn subscribe_notify<F>( &mut self, channel: impl Into<String>, callback: F, ) -> Result<(), Error>

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

Subscribes to notifications on a particular channel.

The call will issue the LISTEN command to PostgreSQL. There is currently no mechanism to unsubscribe even though postgres does supports UNLISTEN.

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

Subscribes to RAISE <level> <message> notifications.

There is currently no mechanism to unsubscribe. This would only require returning some form of “token”, which could be used to unsubscribe.

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

Returns the accumulated log since the last capture.

If the code being called issues many RAISE commands and you never call capture_log, then eventually, you might run out of memory. To ensure that this does not happen, you might consider using with_captured_log instead.

pub async fn with_captured_log<F, T>( &self, f: F, ) -> Result<(T, Vec<PGRaise>), Error>

where F: AsyncFnOnce(&PGClient) -> Result<T, Error>,

Given an async closure taking the postgres client, returns the result of said closure along with the accumulated log since the beginning of the closure.

If you use query pipelining then collect the logs for all queries in the pipeline. Otherwise, the logs might not be what you expect.

Trait Implementations

impl Drop for PGNotifier

fn drop(&mut self)

Executes the destructor for this type.