Struct ConsumerPresenceRegistry 

pub struct ConsumerPresenceRegistry { /* private fields */ }

Process-local registry of consumer presence. Cheap mutex + small hashmap is the right shape: writes are O(1), reads are a single snapshot copy, and the cardinality is bounded by the operator’s worker fleet (typically dozens, not thousands).

Implementations

impl ConsumerPresenceRegistry

pub fn new() -> ConsumerPresenceRegistry

pub fn heartbeat( &self, queue: &str, group: &str, consumer: &str, lease_count: u32, now_ns: u64, )

Record or refresh a heartbeat. now_ns is taken from the caller so tests can drive a deterministic clock and so the runtime can reuse a wall-clock it already captured.

pub fn deregister(&self, queue: &str, group: &str, consumer: &str) -> bool

Explicitly drop a consumer (e.g. on graceful shutdown). Returns whether an entry was actually removed.

pub fn snapshot(&self, now_ns: u64, ttl_ms: u64) -> Vec<ConsumerPresence>

Full snapshot, deterministically ordered by (queue, group, consumer) so test assertions and Red UI tables both see a stable shape.

pub fn count_active_by_group( &self, now_ns: u64, ttl_ms: u64, ) -> HashMap<(String, String), u32>

Active-consumer count per (queue, group). Only entries whose derived state is Active are counted — Red UI surfaces this as the “workers alive on this group right now” number, so stale/expired must not inflate it.

pub fn prune_expired(&self, now_ns: u64, ttl_ms: u64) -> usize

Drop entries whose last_seen_age_ms exceeds 2 * ttl_ms. Returns the number of entries removed. Safe to call on any metadata-read path; not strictly required for correctness (snapshot already classifies them as Expired), but bounds memory after worker churn.

pub fn len(&self) -> usize

Total entry count (active + stale + expired). Mostly useful for tests and debug surfaces.

pub fn is_empty(&self) -> bool

Trait Implementations

impl Debug for ConsumerPresenceRegistry

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

Formats the value using the given formatter.

impl Default for ConsumerPresenceRegistry

fn default() -> ConsumerPresenceRegistry

Returns the “default value” for a type.