Struct ObservationState 

pub struct ObservationState { /* private fields */ }

Cursor and lifecycle tracker; typed consumers own staged view data.

Implementations

impl ObservationState

pub async fn apply<E, F, Fut>( &mut self, frame: &StreamFrame, has_payload: bool, reducer: F, ) -> Result<ObservationAction, ObservationApplyError<E>>

where F: FnOnce(ObservationAction, Vec<u8>) -> Fut, Fut: Future<Output = Result<(), E>>,

Advances this tracker only after the view reducer succeeds. At Commit, the reducer must atomically apply staged data and persist the supplied cursor. A failed reducer leaves the tracker at its previous checkpoint.

pub fn new(binding_digest: [u8; 32], cursor: Vec<u8>) -> Self

pub fn cursor(&self) -> &[u8]

pub fn is_complete(&self) -> bool

pub fn accept( &mut self, frame: &StreamFrame, has_payload: bool, ) -> Result<ObservationAction, StreamProtocolError>

Validate a frame before changing lifecycle state. A rejected frame leaves the state unchanged. Transport adapters enforce negotiated byte budgets before decoding; callers validate the method-specific typed payload.

For reducers that can fail, run this on a clone, apply the returned action, then replace the original tracker only if the reducer succeeds.

Trait Implementations

impl Clone for ObservationState

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.