⚡️(frontend) increase polling interval depend connected users

If we see that someone is connected to the document,
we increase the polling interval. If no one is connected,
we decrease the polling interval.

For the moment, we can only see users connected
with websockets. A good improvement would be to
see users connected with long polling as well.

CHANGELOG.md

@@ -11,7 +11,8 @@ and this project adheres to
 
 ## Added
 
-🔧(helm) add option to disable default tls setting by @dominikkaminski #519
+- 🔧(helm) add option to disable default tls setting by @dominikkaminski #519
+- ✨Collaboration long polling fallback #517
 
 ## Changed
 

src/frontend/apps/impress/src/features/docs/doc-management/api/syncDocPolling.tsx

@@ -9,6 +9,7 @@ interface SyncDocPollingParams {
 
 interface SyncDocPollingResponse {
   yDoc64?: Base64;
+  connectionsCount: number;
 }
 
 export const syncDocPolling = async ({

src/frontend/apps/impress/src/features/docs/doc-management/hooks/useCollaboration.tsx

@@ -14,7 +14,7 @@ export const useCollaboration = (room?: string, initialContent?: Base64) => {
   const { setBroadcastProvider } = useBroadcastStore();
   const { provider, createProvider, destroyProvider, isProviderFailure } =
     useProviderStore();
-  const [pollingInterval] = useState(1500);
+  const [pollingInterval, setPollingInterval] = useState(1500);
   const intervalRef = useRef<NodeJS.Timeout>();
 
   useEffect(() => {
@@ -68,7 +68,9 @@ export const useCollaboration = (room?: string, initialContent?: Base64) => {
         yDoc64: toBase64(Y.encodeStateAsUpdate(provider.document)),
       })
         .then((response) => {
-          const { yDoc64 } = response;
+          const { yDoc64, connectionsCount } = response;
+
+          setPollingInterval(connectionsCount ? 600 : 1500);
 
           if (!yDoc64) {
             return;

src/frontend/servers/y-provider/src/handlers/collaborationConnectionsHandler.ts

@@ -49,10 +49,16 @@ export const collaborationHTTPHandler = async (
     return;
   }
 
-  const syncYDoc64 = await syncDoc(room, yDoc64, canEdit, req);
+  const { syncYDoc64, connectionsCount } = await syncDoc(
+    room,
+    yDoc64,
+    canEdit,
+    req,
+  );
 
   res.status(200).json({
     yDoc64: syncYDoc64,
+    connectionsCount,
   });
 };
 
@@ -69,6 +75,8 @@ const syncDoc = async (
 ) => {
   let docExist = false;
   let syncYDoc = undefined;
+  let connectionsCount = 0;
+
   hocusPocusServer.documents.forEach((hpYDoc) => {
     if (hpYDoc.name !== room) {
       return;
@@ -77,6 +85,7 @@ const syncDoc = async (
     docExist = true;
 
     const hpYDoc64 = toBase64(Y.encodeStateAsUpdate(hpYDoc));
+    connectionsCount = hpYDoc.getConnectionsCount();
 
     // If the document has not changed, return
     if (yDoc64 === hpYDoc64) {
@@ -117,5 +126,8 @@ const syncDoc = async (
     syncYDoc = hpYDoc.merge(ydoc);
   }
 
-  return syncYDoc && toBase64(Y.encodeStateAsUpdate(syncYDoc));
+  return {
+    syncYDoc64: syncYDoc && toBase64(Y.encodeStateAsUpdate(syncYDoc)),
+    connectionsCount,
+  };
 };