Struct SubscriptionManager 

pub struct SubscriptionManager { /* private fields */ }

Thread-safe subscription manager with two-level indexing.

Level 1: entity → set of connection IDs (for fan-out). Level 2: connection → map of entity → subscription details (for per-connection state).

Implementations

impl SubscriptionManager

pub fn new(max_per_entity: usize) -> Self

Create a new subscription manager with the given fan-out limit.

pub fn subscribe( &self, connection_id: &str, entity: &str, details: SubscriptionDetails, ) -> Result<bool, String>

Subscribe a connection to an entity.

Returns Ok(true) if this is a new subscription, Ok(false) if the connection was already subscribed (idempotent).

Errors

Returns an error if the fan-out limit for this entity is reached.

pub fn unsubscribe(&self, connection_id: &str, entity: &str) -> bool

Unsubscribe a connection from an entity.

Returns true if the subscription existed and was removed.

pub fn unsubscribe_all(&self, connection_id: &str)

Remove all subscriptions for a connection (called on disconnect).

pub fn count_for_entity(&self, entity: &str) -> usize

Number of subscriptions for a given entity.

pub fn count_for_connection(&self, connection_id: &str) -> usize

Number of entities a connection is subscribed to.

pub fn get_subscribers( &self, entity: &str, ) -> Option<Vec<(ConnectionId, SubscriptionDetails)>>

Get all subscribers for an entity with their subscription details.

Returns a vec of (connection_id, details) pairs, or None if no connections are subscribed to this entity.