Struct SessionSignals 

pub struct SessionSignals { /* private fields */ }

Tracks session-level signals automatically from events.

Every call to on_event updates the corresponding keys under session: in the shared State, making them available to instruction templates, watchers, and computed vars.

Performance: Timestamps use AtomicU64 (nanos since session start) instead of Mutex<Instant>. Derived timing signals are flushed periodically via flush_timing() (100ms interval) rather than per-event.

Implementations

impl SessionSignals

pub fn new(state: State) -> Self

Create a new SessionSignals backed by the given State.

pub fn on_event(&self, event: &SessionEvent)

Process an event — updates state keys and atomic timestamps.

This is the per-event handler. It updates boolean flags, counters, and atomic timestamps. Derived timing (silence_ms, elapsed_ms, remaining_budget_ms) is NOT computed here — call flush_timing() periodically instead.

pub fn flush_timing(&self)

Flush derived timing signals to state.

Call this periodically (e.g., every 100ms) from the telemetry lane. Computes silence_ms, elapsed_ms, and remaining_budget_ms from atomic timestamps without any mutex locks.

pub fn record_response_latency(&self, latency: Duration)

Record the turn’s response latency (end of user speech, or text send, to the model’s first output) as session:last_response_latency_ms, so instruction templates, watchers and computed vars can react to a slow turn. Called by the telemetry lane once per measured turn.

The write happens when the turn’s first output event is observed, so for a spoken turn it lands a whole model response before the boundary. The telemetry and control lanes are independent readers of the same event stream, though, with no barrier between them: if the telemetry lane is running behind, a turn-boundary reader can still see the previous turn’s value. Treat the key as the latest measurement, not as one synchronised to the current turn.

pub fn session_type(&self) -> SessionType

Returns the current session type based on whether video has been sent.

pub fn latest_resume_handle(&self) -> Option<String>

Returns the latest resumption handle for reconnection.

pub fn mark_video_sent(&self)

Mark that video has been sent (changes session type to AudioVideo).