Struct NotificationHub 

pub struct NotificationHub { /* private fields */ }

Manages notification slots and the SPSC ring for a single reactor core.

Provides the end-to-end path from Ring 0 event emission to Ring 1 dispatch:

1. Registration (Ring 2): Self::register_source allocates a slot.
2. Notification (Ring 0): Self::notify_source increments the slot sequence and pushes a NotificationRef into the SPSC ring.
3. Drain (Ring 1): Self::drain_notifications pops all pending notifications.

Implementations

impl NotificationHub

pub fn new(max_slots: usize, ring_capacity: usize) -> Self

Creates a new notification hub.

Arguments

• max_slots — Maximum number of source slots (determines Vec capacity).
• ring_capacity — SPSC ring capacity (rounded up to power of 2).

pub fn register_source(&mut self) -> Option<u32>

Registers a new source and returns its source_id.

Returns None if the maximum slot count has been reached. This is a Ring 2 operation (may allocate).

pub fn deactivate_source(&self, source_id: u32)

Marks the given source as inactive.

Inactive sources are skipped by Self::notify_source. The slot is not deallocated — use NotificationSlot::reactivate to re-enable.

pub fn notify_source( &self, source_id: u32, event_type: EventType, row_count: u32, timestamp: i64, batch_offset: u64, ) -> bool

Notifies Ring 1 of a data change on the given source (Ring 0 hot path).

Increments the slot’s sequence counter and pushes a NotificationRef into the SPSC ring. Returns false if:

• The source_id is out of range
• The slot is inactive
• The ring is full (backpressure)

pub fn drain_notifications<F: FnMut(NotificationRef)>(&self, f: F) -> usize

Drains all pending notifications from the ring, calling f for each.

Returns the number of notifications drained. This is a Ring 1 operation.

pub fn notification_ring(&self) -> &NotificationRing

Returns a reference to the underlying notification ring.

pub fn source_count(&self) -> usize

Returns the number of registered sources.

pub fn slot(&self, source_id: u32) -> Option<&NotificationSlot>

Returns a reference to the slot for the given source_id.