SSE reconnect, task switcher state/inbox/new task, stream throttle

web/dist/api.js

@@ -46,11 +46,55 @@ export const get = (path, opts) => request("get", path, opts);
 export const post = (path, opts) => request("post", path, opts);
 export const put = (path, opts) => request("put", path, opts);
 export const del = (path, opts) => request("delete", path, opts);
+const staleAfterMs = 40_000;
+const retryAfterMs = 2_000;
 export function subscribe(after, onEvent, onState) {
-    const source = new EventSource(`/api/events?after=${after}`);
-    source.onopen = () => onState(true);
-    source.onerror = () => onState(false);
-    source.onmessage = (msg) => onEvent(JSON.parse(msg.data));
-    return source;
+    let last = after;
+    let heard = Date.now();
+    let source;
+    let retry = 0;
+    const connect = () => {
+        clearTimeout(retry);
+        source?.close();
+        heard = Date.now();
+        const s = new EventSource(`/api/events?after=${last}`);
+        source = s;
+        s.onopen = () => {
+            heard = Date.now();
+            onState(true);
+        };
+        s.onerror = () => {
+            onState(false);
+            if (s.readyState === EventSource.CLOSED) {
+                retry = setTimeout(connect, retryAfterMs);
+            }
+        };
+        s.addEventListener("ping", () => {
+            heard = Date.now();
+        });
+        s.onmessage = (msg) => {
+            heard = Date.now();
+            const ev = JSON.parse(msg.data);
+            if (ev.seq > last) {
+                last = ev.seq;
+            }
+            onEvent(ev);
+        };
+    };
+    const check = () => {
+        if (Date.now() - heard < staleAfterMs) {
+            return;
+        }
+        onState(false);
+        connect();
+    };
+    setInterval(check, 5_000);
+    addEventListener("online", connect);
+    document.addEventListener("visibilitychange", () => {
+        if (document.visibilityState === "visible") {
+            check();
+        }
+    });
+    connect();
 }
 //# sourceMappingURL=api.js.map