Enum Delivery 

pub enum Delivery {
    Lossless,
    LossyDropNewest,
}

Backpressure (delivery) policy for a single class of fast-lane events.

The event router forwards fast-lane frames (audio, text, transcripts, thoughts, VAD, phase) over a bounded channel to the fast-lane consumer. When that consumer falls behind and the channel fills, the policy decides what the router does — and crucially, whether the router blocks. Because the router is shared by both the fast lane and the control lane, a blocking fast-lane send stalls routing for all events, including control-lane lifecycle and tool events. The policy lets callers trade frame durability for router responsiveness on a per-class basis.

Variants

Lossless

Never drop a frame: tx.send(ev).await — the router awaits when the channel is full. This is the historical (and default) behavior and is byte-for-byte identical to the pre-policy code path. Use it when every frame matters and a slow consumer applying backpressure to the router is acceptable.

LossyDropNewest

Drop the newest frame on overflow: tx.try_send(ev) and, on TrySendError::Full, discard the just-produced frame and bump a dropped-frame counter. The router never blocks on this class, so a slow fast-lane consumer can no longer stall control-lane routing. Use it for high-frequency, loss- tolerant streams (e.g. partial transcripts, thoughts) where freshness of already-queued frames matters less than keeping the router moving.

A drop-oldest / latest-only variant is intentionally not provided: tokio’s mpsc has no clean “evict the oldest queued item” primitive, so implementing it correctly would require a custom ring buffer. That is left as future work rather than shipped half-working.

Trait Implementations

impl Clone for Delivery

fn clone(&self) -> Delivery

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Delivery

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

Formats the value using the given formatter.

impl Default for Delivery

fn default() -> Delivery

Returns the “default value” for a type.

impl PartialEq for Delivery

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Delivery

impl Eq for Delivery

impl StructuralPartialEq for Delivery