Struct ObservationCell 

pub struct ObservationCell { /* private fields */ }

Per-key continuity state machine (plan §3.4 transitions). Owns the observation, both deadlines, and the projection; callers feed it only gate-admitted beats (super::IncarnationSeqGate) and drive time explicitly through expire_if_due — no hidden clock reads, so every SI-0 test controls the timeline.

Implementations

impl ObservationCell

pub fn register(now: Instant, own_interval: Duration, factor: u32) -> Self

Interest registration (plan §3.4): continuity starts Unestablished and the establishment deadline starts counting — before any beat arrives there is no promised_cadence, so the window derives from the consumer’s own D alone.

pub fn update_interval(&mut self, own_interval: Duration)

SI-4 review (interval update): the consumer’s — or the relay’s aggregate — own D moved. Recompute the CURRENT deadline for the new window WITHOUT resetting continuity and without waiting for a fresh beat: the deadline’s anchor (the last qualifying event) is preserved by shifting the deadline by the window delta, so tightening pulls the deadline earlier and loosening pushes it later, exactly. A no-op when the interval is unchanged; skipped once Expired (the deadline is meaningless there — the next beat rebuilds state as usual).

pub fn on_admitted_beat(&mut self, now: Instant, beat: DeliveredBeat)

Apply one gate-admitted beat.

• A continuity-bearing beat establishes (from Unestablished, Established, or Expired — a resumed live stream is how continuity recovers) and re-arms the suspicion deadline from max(promised_cadence, own D).
• A warm-start beat updates the attested content but NEVER touches continuity or either deadline: a chain of strictly-newer cached beats is not a live stream, so it must neither establish nor postpone expiry (SI-0 tests 13/14).
• Continuity never carries across an incarnation boundary: a warm-started beat from a NEW incarnation expires ESTABLISHED continuity (§4.7) — the earned optimism the old stream can no longer vouch for — until the new stream establishes on its own live beat. An Unestablished cell has no earned optimism to revoke: a cached Ready still projects Unknown and a cached NotReady still projects NotReady (pessimism is safe), both bounded by the unchanged establishment deadline.
• Continuity never carries across a GENERATION boundary either (v4.1, §3.4) — but a generation change is a redefinition, not a failure signal: the cell resets to a fresh observation (Unestablished, establishment deadline restarted), so a warm-started NotReady under the new generation still projects (pessimism is safe) while a warm-started Ready must earn continuity anew.

pub fn expire_if_due(&mut self, now: Instant)

Drive the clock: past-deadline Unestablished OR Established states expire (plan §3.4 — “Unestablished expires too”).

pub fn disrupt(&mut self, reason: DisruptReason)

Force-expire (plan §4.7): route withdrawal, path failure, generation change, scope-validation failure.

pub fn projected(&self) -> ProjectedReadiness

Current projection (no observation yet → Unknown).

pub const fn continuity(&self) -> Continuity

Current continuity state.

pub fn observation(&self) -> Option<&ReadinessObservation>

The latest admitted observation, if any.

pub const fn last_disrupt(&self) -> Option<DisruptReason>

The reason for the last forced expiry, if continuity was disrupted rather than timed out.

Trait Implementations

impl Debug for ObservationCell

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.