Struct PlacementCache 

pub struct PlacementCache { /* private fields */ }

A short-TTL cache over NamespaceStore::get_namespace’s placement field.

Cheap to clone (shares the inner store handle + map). A miss / expired entry reads the durable store once and re-caches; a backend error degrades to NamespacePlacement::Unplaced (the safe default = today’s any-worker behaviour) rather than failing the dispatch, since placement is a soft optimization and a row must still dispatch when the registry read hiccups.

Implementations

impl PlacementCache

pub fn new(store: Arc<dyn NamespaceStore>, ttl: Duration) -> Self

Build a cache over the durable namespace store with the given entry TTL.

pub async fn placement(&self, namespace: &str) -> NamespacePlacement

Return the namespace’s placement, serving a fresh cache hit without a store read and refreshing on a miss / expiry.

A poisoned cache lock or a store-read failure falls back to NamespacePlacement::Unplaced — the dispatch then behaves exactly as the pre-Phase-2 any-worker path, so a registry hiccup never blocks a dispatch.

Trait Implementations

impl Clone for PlacementCache

fn clone(&self) -> PlacementCache

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PlacementCache

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

Formats the value using the given formatter.