Struct MessageBus 

pub struct MessageBus { /* private fields */ }

Subscriber/cursor message bus with idempotent send and consume.

Implementations

impl MessageBus

pub const fn new() -> Self

Create an empty message bus.

pub const fn with_maxlen(maxlen: usize) -> Self

Create an empty message bus with a bounded retention length.

pub fn subscribe(&mut self, agent_id: impl Into<String>)

Register a subscriber. New subscribers start at the current tail.

pub fn unsubscribe(&mut self, agent_id: &str)

Remove a subscriber and its cursor state.

pub fn is_subscribed(&self, agent_id: &str) -> bool

Return whether the given agent currently has a subscriber cursor.

pub fn send(&mut self, message: BusMessage) -> BusMessage

Send a message idempotently.

pub fn consume(&mut self, agent_id: impl Into<String>) -> Vec<BusMessage>

Consume unread messages for a subscriber.

pub fn consume_matching( &mut self, agent_id: impl Into<String>, predicate: impl Fn(&BusMessage) -> bool, ) -> Vec<BusMessage>

Consume unread messages matching a predicate while preserving other pending messages.

pub fn peek(&self, agent_id: &str) -> Vec<BusMessage>

Return unread messages without advancing the cursor.

pub fn mark_consumed( &mut self, agent_id: impl Into<String>, message_ids: &BTreeSet<String>, ) -> usize

Mark specific unread messages as consumed for a subscriber.

Returns the number of currently unread messages that were marked consumed.

pub fn has_pending(&self, agent_id: &str) -> bool

Return whether there are pending messages for one subscriber.

pub fn has_topic(&self, topic: &str) -> bool

Return whether any queued message has the provided topic.

pub fn clear(&mut self)

Clear all messages and subscriber state.

pub const fn len(&self) -> usize

Return number of retained messages.

pub fn subscriber_count(&self) -> usize

Return number of subscribers.

pub const fn is_empty(&self) -> bool

Return whether the bus has no messages.

pub fn messages(&self) -> &[BusMessage]

Return retained messages.

Trait Implementations

impl Clone for MessageBus

fn clone(&self) -> MessageBus

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MessageBus

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

Formats the value using the given formatter.

impl Default for MessageBus

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for MessageBus

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for MessageBus

impl PartialEq for MessageBus

fn eq(&self, other: &MessageBus) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for MessageBus

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for MessageBus