Struct ChangeFeed 

pub struct ChangeFeed { /* private fields */ }

Ordered stream of committed ChangeBatches from one database.

Poll it with Self::poll (non-blocking) or Self::next_timeout. Dropping the feed unsubscribes it.

Implementations

impl ChangeFeed

pub fn last_lsn(&self) -> Option<u64>

LSN of the last batch this feed delivered (or the from_lsn it was opened with). Pass it as from_lsn to resume.

pub fn closer(&self) -> ChangeFeedCloser

Handle for closing this feed from another thread.

pub fn close(&self)

Close the feed. Later polls return ChangePoll::Closed.

pub fn set_waker(&self, waker: impl Fn() + Send + Sync + 'static)

Install a callback that fires when the feed goes from empty to non-empty, lags, or closes. It runs on the writing thread while the writer lock is held, so it must be quick and must not call back into the database.

pub fn poll(&mut self) -> Result<ChangePoll, LoraError>

Next batch without blocking. History replay (resuming from an LSN older than the in-memory window) does its work inside this call.

Fails with LORA_CHANGES_LAGGED once the feed has fallen behind and its buffered batches are drained; the feed is closed afterwards.

pub fn next_timeout( &mut self, timeout: Duration, ) -> Result<ChangePoll, LoraError>

Block until a batch arrives, the feed closes, or timeout passes (then ChangePoll::Pending).

Trait Implementations

impl Drop for ChangeFeed

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.