Struct GraphObserveOne 

pub struct GraphObserveOne { /* private fields */ }

Single-node observe handle (canonical §3.6.2).

D246: holds a Core-free Graph; &Core is passed per call.

Deliberate divergence from canonical R3.6.2 up(messages) (D280 doc-lock)

Canonical R3.6.2 specifies a unified up(messages: Messages) upstream-injection API. This impl exposes the per-tier control methods Self::pause / Self::resume / Self::invalidate as separate methods rather than a single up(messages) shape. The split is deliberate, on two grounds:

1. Non-allocating ergonomics. A unified up(Vec<Message>) forces a Vec allocation on every upstream call. The per-tier methods take their args by value and take a direct path into Core::pause / Core::resume / Core::invalidate — zero heap churn on the control plane.

2. Avoids re-exposing an imperative-shaped public surface. The Rust port’s collaboration directive (feedback_no_imperative user memory) is to expose reactive NodeInput shapes at the public surface, not imperative message-injection. The per-tier methods read as intent-named control calls (pause(lock), resume(lock), invalidate()); a unified up([PAUSE, lock]) re-exposes the protocol-internal Messages shape and tier numbers as call-site vocabulary.

Cross-binding wrappers (napi-rs BenchGraph, future pyo3, etc.) may reassemble a unified up(messages) if a JS/Python idiomatic API needs it; the substrate-side split is the Rust public-surface contract.

Lift point (only if needed)

If a Rust consumer surfaces a need for a unified up(messages) — e.g., a cross-impl parity scenario authored against the canonical R3.6.2 shape — add it alongside the per-tier methods (additive, non-breaking). Gated on D196 consumer pressure.

Implementations

impl GraphObserveOne

pub fn node_id(&self) -> NodeId

The observed NodeId.

pub fn subscribe(&self, core: &Core, sink: Sink) -> ObserveSub

Subscribe a sink. Returns an ObserveSub id pair — detach owner-invoked (D246 rule 3).

pub fn pause(&self, core: &Core, lock: LockId) -> Result<(), PauseError>

Send [PAUSE, lock] upstream.

Errors

See PauseError.

pub fn resume( &self, core: &Core, lock: LockId, ) -> Result<Option<ResumeReport>, PauseError>

Send [RESUME, lock] upstream.

Errors

See PauseError.

pub fn invalidate(&self, core: &Core)

Send [INVALIDATE] upstream.

pub fn graph(&self) -> &Graph

The backing graph handle.