Function start

packages/server/external-annotations.ts:93–115

(controller)

        const stream = new ReadableStream({
          start(controller) {
            ctrl = controller;

            // Send current state as snapshot
            const snapshot: ExternalAnnotationEvent<StorableAnnotation> = {
              type: "snapshot",
              annotations: store.getAll(),
            };
            controller.enqueue(encoder.encode(serializeSSEEvent(snapshot)));

            subscribers.add(controller);

            // Heartbeat to keep connection alive
            heartbeatTimer = setInterval(() => {
              try {
                controller.enqueue(encoder.encode(HEARTBEAT_COMMENT));
              } catch {
                // Stream closed
                if (heartbeatTimer) clearInterval(heartbeatTimer);
                subscribers.delete(controller);
              }
            }, HEARTBEAT_INTERVAL_MS);
          },
          cancel() {
            if (heartbeatTimer) clearInterval(heartbeatTimer);
            subscribers.delete(ctrl);