refactor(gateway): split server runtime

src/gateway/server-broadcast.ts

@@ -0,0 +1,56 @@
+import type { GatewayWsClient } from "./server/ws-types.js";
+import { MAX_BUFFERED_BYTES } from "./server-constants.js";
+import { logWs, summarizeAgentEventForWsLog } from "./ws-log.js";
+
+export function createGatewayBroadcaster(params: {
+  clients: Set<GatewayWsClient>;
+}) {
+  let seq = 0;
+  const broadcast = (
+    event: string,
+    payload: unknown,
+    opts?: {
+      dropIfSlow?: boolean;
+      stateVersion?: { presence?: number; health?: number };
+    },
+  ) => {
+    const eventSeq = ++seq;
+    const frame = JSON.stringify({
+      type: "event",
+      event,
+      payload,
+      seq: eventSeq,
+      stateVersion: opts?.stateVersion,
+    });
+    const logMeta: Record<string, unknown> = {
+      event,
+      seq: eventSeq,
+      clients: params.clients.size,
+      dropIfSlow: opts?.dropIfSlow,
+      presenceVersion: opts?.stateVersion?.presence,
+      healthVersion: opts?.stateVersion?.health,
+    };
+    if (event === "agent") {
+      Object.assign(logMeta, summarizeAgentEventForWsLog(payload));
+    }
+    logWs("out", "event", logMeta);
+    for (const c of params.clients) {
+      const slow = c.socket.bufferedAmount > MAX_BUFFERED_BYTES;
+      if (slow && opts?.dropIfSlow) continue;
+      if (slow) {
+        try {
+          c.socket.close(1008, "slow consumer");
+        } catch {
+          /* ignore */
+        }
+        continue;
+      }
+      try {
+        c.socket.send(frame);
+      } catch {
+        /* ignore */
+      }
+    }
+  };
+  return { broadcast };
+}