Enum TrackingPolicy 

#[non_exhaustive]
pub enum TrackingPolicy {
    Slots {
        slots: Vec<U256>,
    },
    WholeAccount,
    Scalars,
}

How a tracked account is kept live by the per-block root gate (Phase-8 step 4).

The storageHash root gate behaves oppositely for two contract shapes, so liveness strategy is per-contract:

• A sparse-interest contract (a few balance slots, e.g. WETH) has its root churn on nearly every block, so the root is a noisy gate — Slots opts out. Its enumerated slots stay fresh via decoders + cadence reconcile.
• A whole-economic-state contract (e.g. a Uniswap-V2 pool) has root_moved ≈ my_state_changed, so WholeAccount opts in: probe the root each canonical block; a move a decoder did not cover is a coverage gap.

A false-positive resync is never incorrect — it costs one batched read — so the policy is a pure cost knob, not a correctness lever.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Slots

Sparse interest (e.g. WETH: a few balance slots). The root churns on nearly every block, so it is a noisy gate — this policy is never root-gated (spec Decision 3). Keep the enumerated slots fresh via decoders and cadence reconcile.

Fields

slots: Vec<U256>

The enumerated storage slots of interest.

WholeAccount

Whole economic state (e.g. a V2 pool). root_moved ≈ my_state_changed, so the root is a tight, cheap gate: probe each canonical block; on a move no decoder covered, emit a ReactiveReport::CoverageGap and schedule a ResyncReason::RootMoved repair.

Scalars

Balance / nonce / code-hash only — resolved from the same get_proof response’s account fields; no storage interest. Native balance/nonce changes do not move the storage root, so this policy compares the account fields directly across blocks rather than root-gating.

Trait Implementations

impl Clone for TrackingPolicy

fn clone(&self) -> TrackingPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TrackingPolicy

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

Formats the value using the given formatter.