Struct SubscriptionRegistry 

pub struct SubscriptionRegistry { /* private fields */ }

Registry managing all active subscriptions.

Thread-safe via internal RwLock. Read operations (used by the Ring 1 dispatcher) take a read lock. Write operations (create/cancel) take a write lock but are rare Ring 2 operations.

Three indices provide O(1) lookups:

• subscriptions: by SubscriptionId
• by_source: by source_id (u32) — used by the dispatcher
• by_name: by source name (String) — used by admin API

Panics

All methods on this type panic if an internal RwLock has been poisoned (i.e., a thread panicked while holding the lock). This should not occur under normal operation.

Implementations

impl SubscriptionRegistry

pub fn new() -> Self

Creates a new empty registry.

pub fn create( &self, source_name: String, source_id: u32, config: SubscriptionConfig, ) -> (SubscriptionId, Receiver<ChangeEvent>)

Creates a new subscription for the given source.

Returns the subscription ID and a broadcast Receiver that the subscriber uses to receive ChangeEvents.

Arguments

• source_name — Name of the MV or streaming query.
• source_id — Ring 0 source identifier (from NotificationHub).
• config — Subscription configuration (buffer size, backpressure, etc.).

pub fn pause(&self, id: SubscriptionId) -> bool

Pauses an active subscription.

Returns true if the subscription was Active and is now Paused. Returns false if the subscription does not exist or is not active.

pub fn resume(&self, id: SubscriptionId) -> bool

Resumes a paused subscription.

Returns true if the subscription was Paused and is now Active. Returns false if the subscription does not exist or is not paused.

pub fn cancel(&self, id: SubscriptionId) -> bool

Cancels a subscription and removes it from all indices.

Returns true if the subscription existed and was removed.

pub fn get_senders_for_source(&self, source_id: u32) -> Vec<Sender<ChangeEvent>>

Returns broadcast senders for all active subscriptions of a source.

Called by the Ring 1 dispatcher on every notification. Uses a read lock for fast concurrent access.

pub fn get_subscriptions_by_name(&self, name: &str) -> Vec<SubscriptionId>

Returns subscription IDs for the given source name.

pub fn subscription_count(&self) -> usize

Returns the total number of registered subscriptions.

pub fn active_count(&self) -> usize

Returns the number of active subscriptions.

pub fn metrics(&self, id: SubscriptionId) -> Option<SubscriptionMetrics>

Returns a metrics snapshot for the given subscription.

pub fn state(&self, id: SubscriptionId) -> Option<SubscriptionState>

Returns the state of a subscription.

pub fn record_delivery(&self, id: SubscriptionId, count: u64)

Increments the delivered event count for a subscription.

Called by the Ring 1 dispatcher after successful delivery.

pub fn record_drop(&self, id: SubscriptionId, count: u64)

Increments the dropped event count for a subscription.

Called by the Ring 1 dispatcher on backpressure.

Trait Implementations

impl Default for SubscriptionRegistry

fn default() -> Self

Returns the “default value” for a type.