snapshot of https://github.com/jitsi/jitsi-meet.git @ fd1749dd28f4138aa80234fc7f311b19aaffa0e7 (2026-09-15)

react/features/base/app/middleware.web.ts

@@ -0,0 +1,54 @@
+import { AnyAction } from 'redux';
+
+import MiddlewareRegistry from '../redux/MiddlewareRegistry';
+import { isEmbedded } from '../util/embedUtils';
+
+import { APP_WILL_MOUNT, APP_WILL_UNMOUNT } from './actionTypes';
+import logger from './logger';
+
+
+/**
+ * Experimental feature to monitor CPU pressure.
+ */
+let pressureObserver: typeof window.PressureObserver;
+
+/**
+ * Middleware which intercepts app actions to handle changes to the related state.
+ *
+ * @param {Store} store - The redux store.
+ * @returns {Function}
+ */
+MiddlewareRegistry.register(() => (next: Function) => (action: AnyAction) => {
+
+    switch (action.type) {
+    case APP_WILL_MOUNT: {
+        // Disable it inside an iframe until Google fixes the origin trial for 3rd party sources:
+        // https://bugs.chromium.org/p/chromium/issues/detail?id=1504167
+        if (!isEmbedded() && 'PressureObserver' in window) {
+            pressureObserver = new window.PressureObserver(
+                    (records: typeof window.PressureRecord) => {
+                        logger.info('Compute pressure state changed:', JSON.stringify(records));
+                        APP.API.notifyComputePressureChanged(records);
+                    }
+            );
+
+            try {
+                pressureObserver
+                    .observe('cpu', { sampleInterval: 30_000 })
+                    .catch((e: any) => logger.error('CPU pressure observer failed to start', e));
+            } catch (e: any) {
+                logger.error('CPU pressure observer failed to start', e);
+            }
+        }
+        break;
+    }
+    case APP_WILL_UNMOUNT: {
+        if (pressureObserver) {
+            pressureObserver.unobserve('cpu');
+        }
+        break;
+    }
+    }
+
+    return next(action);
+});