Struct WatchRegistry 

pub struct WatchRegistry { /* private fields */ }

Watch registry — manages watcher registration (Arc-shareable).

Two independent DashMaps keep exact and prefix watchers separate so dispatch can use different lookup strategies for each without coupling.

Implementations

impl WatchRegistry

pub fn new( watcher_buffer_size: usize, unregister_tx: UnboundedSender<(u64, Bytes)>, ) -> Self

Create a new registry with no watcher count limit.

pub fn new_with_limits( watcher_buffer_size: usize, max_watcher_count: usize, unregister_tx: UnboundedSender<(u64, Bytes)>, ) -> Self

Create a new registry with a hard watcher count cap.

register() and register_prefix() return WatchError::LimitExceeded once max_watcher_count active watchers are registered.

pub fn register( &self, key: Bytes, prev_kv: bool, ) -> Result<WatcherHandle, WatchError>

Register an exact-key watcher.

prev_kv: when true the server reads the old value before each write and populates WatchEvent::prev_value. Only pays the read cost when at least one watcher has prev_kv = true.

Returns WatchError::LimitExceeded if max_watcher_count is reached.

pub fn register_prefix( &self, prefix: Bytes, prev_kv: bool, ) -> Result<WatcherHandle, WatchError>

Register a prefix watcher.

prefix must start with ‘/’ and end with ‘/’. E.g. “/config/” watches all keys under /config/.

prev_kv: same semantics as register().

Returns WatchError::InvalidPrefix if format is wrong. Returns WatchError::LimitExceeded if max_watcher_count is reached.

pub fn prev_kv_watcher_count(&self) -> usize

Number of active watchers that opted in to prev_kv.

pub fn prev_kv_watcher_count_arc(&self) -> Arc<AtomicUsize>

Clone of the shared prev_kv counter Arc.

Pass this to DefaultStateMachineHandler so it can poll the live value without holding a reference to the registry.