Struct PubSubHub 

pub struct PubSubHub { /* private fields */ }

The subscription registry of one server.

Implementations

impl PubSubHub

pub fn check_subscribe( &self, conn: u32, kind: Kind, names: &[Vec<u8>], ) -> Result<(), String>

Whether names could be subscribed by conn without breaking a bound. Called before the model is asked, so a request that can never be honoured costs no model call, and again inside Self::subscribe because the hub may have changed while it was asked.

pub fn subscribe( &self, conn: u32, outbox: &Outbox, proto: &Arc<AtomicU8>, kind: Kind, names: &[Vec<u8>], ) -> Result<(), String>

Subscribe conn to names and queue one confirmation per name on its outbox, in order, under the hub lock. All or nothing: a bound breached by any name refuses the whole command, and Err is the RESP error to send.

pub fn unsubscribe( &self, conn: u32, outbox: &Outbox, proto: u8, kind: Kind, names: &[Vec<u8>], )

Unsubscribe conn from names, or from everything of kind when names is empty, queuing one confirmation per name. With nothing to unsubscribe from, Redis still answers once, with a null name and the current count; so does this.

pub fn remove_connection(&self, conn: u32)

Forget every subscription conn holds, without confirmations: the connection closed, or sent RESET.

pub fn subscription_count(&self, conn: u32) -> usize

Subscriptions conn holds (channels + patterns + shard channels). Above zero, a RESP2 connection is in subscribed mode.

pub fn receivers(&self, channel: &[u8], shard: bool) -> usize

How many deliveries a publish would make right now, for the model’s event.

pub fn publish(&self, channel: &[u8], message: &[u8], shard: bool) -> usize

Deliver message on channel to every matching subscription and return how many deliveries were queued — Redis’s PUBLISH reply, where a connection subscribed to the channel and to a matching pattern receives (and counts) twice.

A subscriber the delivery would take past SUBSCRIBER_OUTPUT_LIMIT_BYTES is not counted, is dropped from the hub, and its connection is woken to close.

pub fn active_channels( &self, shard: bool, pattern: Option<&[u8]>, ) -> Vec<Vec<u8>>

PUBSUB CHANNELS / SHARDCHANNELS: active channels, optionally filtered by a pattern.

pub fn numsub(&self, shard: bool, channels: &[Vec<u8>]) -> Vec<(Vec<u8>, usize)>

PUBSUB NUMSUB / SHARDNUMSUB: subscribers of each named channel.

pub fn numpat(&self) -> usize

PUBSUB NUMPAT: distinct patterns subscribed across the server.

pub fn snapshot(&self) -> Value

Subscriptions across the server, for list_redis_subscriptions.

Trait Implementations

impl Default for PubSubHub

fn default() -> Self

Returns the “default value” for a type.