perf(permissions): cache space role and page edit lookups (#2208)

apps/server/src/common/helpers/with-cache.ts

@@ -0,0 +1,27 @@
+import { Cache } from 'cache-manager';
+
+export async function withCache<T>(
+  cacheManager: Cache,
+  key: string,
+  ttlMs: number,
+  fn: () => Promise<T>,
+): Promise<T> {
+  try {
+    const cached = await cacheManager.get<{ v: T }>(key);
+    if (cached !== undefined && cached !== null) {
+      return cached.v;
+    }
+  } catch (err) {
+    console.warn(`[withCache] get failed for "${key}", falling back to source`, err);
+  }
+
+  const value = await fn();
+
+  try {
+    await cacheManager.set(key, { v: value }, ttlMs);
+  } catch (err) {
+    console.warn(`[withCache] set failed for "${key}"`, err);
+  }
+
+  return value;
+}