Struct ChatTurnQueue 

pub struct ChatTurnQueue { /* private fields */ }

Per-chat turn serialization queue.

Ensures at most one agent run per (channel, chat_id). Messages arriving during an active run are coalesced into pending_messages and can be drained after the run completes.

Implementations

impl ChatTurnQueue

pub fn new(max_pending: usize) -> Self

pub async fn acquire( self: &Arc<Self>, channel: &str, chat_id: i64, ) -> Option<TurnGuard>

Acquire the turn for a chat. Blocks until the previous run completes. Returns a TurnGuard that releases the turn when dropped.

pub async fn enqueue_if_busy( &self, channel: &str, chat_id: i64, msg: PendingMessage, ) -> bool

Enqueue a message for a chat that currently has an active run.

Returns true if the chat has an active run (message was queued). Returns false if no run is active (caller should start a new run).

pub async fn try_start_or_enqueue( self: &Arc<Self>, channel: &str, chat_id: i64, msg: PendingMessage, ) -> Option<TurnGuard>

Atomically try to start a new turn or enqueue the message.

If no turn is active, acquires the lock and returns Some(TurnGuard). If a turn is active, queues the message and returns None.

This avoids the race window between a separate enqueue_if_busy check and a later acquire() call.

pub async fn drain_pending( &self, channel: &str, chat_id: i64, ) -> Vec<PendingMessage>

Drain all pending messages accumulated during the current turn. Returns them in arrival order.