Enum WorkerSelection 

pub enum WorkerSelection {
    PreferTiers(Vec<Option<String>>),
    Required(BTreeSet<String>),
}

How an UNPINNED outbox row (row.node == None) must be dispatched given its namespace’s NamespacePlacement — the SINGLE decision shared by BOTH the gRPC (WorkerOutboxDispatch) and liminal (RegistryLiminalDispatch) dispatch paths, so the two transports can never diverge on Prefer (spill) vs Pinned (require + wait, NEVER spill) semantics.

This is consulted ONLY for an unpinned row: an authored Some(N) pin is authoritative and never enters this path. The result is a pure worker-SELECTION input; it never mutates the recorded row’s node (the determinism invariant, CP-Phase-2 §2.4).

Variants

PreferTiers(Vec<Option<String>>)

Unplaced/Prefer: try the ordered tiers (each preferred label, then the None spill), stopping at the first tier with a live worker. Unplaced collapses to the single None any-worker tier.

Required(BTreeSet<String>)

Pinned{L}: require a worker whose advertised node ∈ L, and WAIT when none is live — NEVER a None spill to an any-node worker (CP-Phase-2 §2.5, P2-I1). An empty required set can never be satisfied by any labelled worker, so it stalls until the namespace’s placement is relaxed — the correct “isolation > availability” behaviour of a hard pin with no admissible node.

Trait Implementations

impl Clone for WorkerSelection

fn clone(&self) -> WorkerSelection

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WorkerSelection

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

Formats the value using the given formatter.

impl Eq for WorkerSelection

impl PartialEq for WorkerSelection

fn eq(&self, other: &WorkerSelection) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for WorkerSelection