feat: mutual friend graph (#1491)

src/shared/utils/throttle.js

@@ -0,0 +1,28 @@
+export function createRateLimiter({ limitPerInterval, intervalMs }) {
+    const stamps = [];
+
+    async function throttle() {
+        const now = Date.now();
+        while (stamps.length && now - stamps[0] > intervalMs) {
+            stamps.shift();
+        }
+        if (stamps.length >= limitPerInterval) {
+            const wait = intervalMs - (now - stamps[0]);
+            await new Promise((resolve) => setTimeout(resolve, wait));
+        }
+        stamps.push(Date.now());
+    }
+
+    return {
+        async schedule(fn) {
+            await throttle();
+            return fn();
+        },
+        async wait() {
+            await throttle();
+        },
+        clear() {
+            stamps.length = 0;
+        }
+    };
+}