Struct SubscriptionManager

pub struct SubscriptionManager { /* private fields */ }

Responsible for the efficient evaluation of subscriptions. It performs basic multi-query optimization, in that if a query has N subscribers, it is only executed once, with the results copied to the N receivers.

Implementations

impl SubscriptionManager

pub fn for_test_without_metrics_arc_rwlock() -> Arc<RwLock<Self>>

pub fn for_test_without_metrics() -> Self

pub fn new(send_worker_queue: BroadcastQueue) -> Self

pub fn query(&self, hash: &QueryHash) -> Option<Arc<Plan>>

pub fn calculate_gauge_stats(&self) -> SubscriptionGaugeStats

pub fn num_unique_queries(&self) -> usize

pub fn remove_dropped_clients(&mut self)

Remove any clients that have been marked for removal

pub fn remove_subscription( &mut self, client_id: (Identity, ConnectionId), query_id: QueryId, ) -> Result<Vec<Arc<Plan>>, DBError>

Remove a single subscription for a client. This will return an error if the client does not have a subscription with the given query id.

pub fn add_subscription( &mut self, client: Arc<ClientConnectionSender>, query: Arc<Plan>, query_id: QueryId, ) -> Result<(), DBError>

Adds a single subscription for a client.

pub fn add_subscription_multi( &mut self, client: Arc<ClientConnectionSender>, queries: Vec<Arc<Plan>>, query_id: QueryId, ) -> Result<Vec<Arc<Plan>>, DBError>

pub fn set_legacy_subscription( &mut self, client: Arc<ClientConnectionSender>, queries: impl IntoIterator<Item = Arc<Plan>>, )

Adds a client and its queries to the subscription manager. Sets up the set of subscriptions for the client, replacing any existing legacy subscriptions.

If a query is not already indexed, its table ids added to the inverted index.

pub fn remove_all_subscriptions(&mut self, client: &(Identity, ConnectionId))

Removes a client from the subscriber mapping. If a query no longer has any subscribers, it is removed from the index along with its table ids.

pub fn index_ids_for_subscriptions(&self) -> &QueriedTableIndexIds

Returns the index ids that are used in subscription queries

pub fn eval_updates_sequential( &self, tx: &DeltaTx<'_>, event: Arc<ModuleEvent>, caller: Option<Arc<ClientConnectionSender>>, ) -> ExecutionMetrics

This method takes a set of delta tables, evaluates only the necessary queries for those delta tables, and then sends the results to each client.

This previously used rayon to parallelize subscription evaluation. However, in order to optimize for the common case of small updates, we removed rayon and switched to a single-threaded execution, which removed significant overhead associated with thread switching.

Trait Implementations

impl Debug for SubscriptionManager

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

Formats the value using the given formatter.