refactor: consolidate core runtime state helpers

src/shared/listeners.ts

@@ -0,0 +1,21 @@
+export function notifyListeners<T>(
+  listeners: Iterable<(event: T) => void>,
+  event: T,
+  onError?: (error: unknown) => void,
+): void {
+  for (const listener of listeners) {
+    try {
+      listener(event);
+    } catch (error) {
+      onError?.(error);
+    }
+  }
+}
+
+export function registerListener<T>(
+  listeners: Set<(event: T) => void>,
+  listener: (event: T) => void,
+): () => void {
+  listeners.add(listener);
+  return () => listeners.delete(listener);
+}

src/shared/scoped-expiring-id-cache.ts

@@ -0,0 +1,57 @@
+export type ScopedExpiringIdCache<TScope extends string | number, TId extends string | number> = {
+  record: (scope: TScope, id: TId, now?: number) => void;
+  has: (scope: TScope, id: TId, now?: number) => boolean;
+  clear: () => void;
+};
+
+export function createScopedExpiringIdCache<
+  TScope extends string | number,
+  TId extends string | number,
+>(options: {
+  store: Map<string, Map<string, number>>;
+  ttlMs: number;
+  cleanupThreshold: number;
+}): ScopedExpiringIdCache<TScope, TId> {
+  const ttlMs = Math.max(0, options.ttlMs);
+  const cleanupThreshold = Math.max(1, Math.floor(options.cleanupThreshold));
+
+  function cleanupExpired(scopeKey: string, entry: Map<string, number>, now: number): void {
+    for (const [id, timestamp] of entry) {
+      if (now - timestamp > ttlMs) {
+        entry.delete(id);
+      }
+    }
+    if (entry.size === 0) {
+      options.store.delete(scopeKey);
+    }
+  }
+
+  return {
+    record: (scope, id, now = Date.now()) => {
+      const scopeKey = String(scope);
+      const idKey = String(id);
+      let entry = options.store.get(scopeKey);
+      if (!entry) {
+        entry = new Map<string, number>();
+        options.store.set(scopeKey, entry);
+      }
+      entry.set(idKey, now);
+      if (entry.size > cleanupThreshold) {
+        cleanupExpired(scopeKey, entry, now);
+      }
+    },
+    has: (scope, id, now = Date.now()) => {
+      const scopeKey = String(scope);
+      const idKey = String(id);
+      const entry = options.store.get(scopeKey);
+      if (!entry) {
+        return false;
+      }
+      cleanupExpired(scopeKey, entry, now);
+      return entry.has(idKey);
+    },
+    clear: () => {
+      options.store.clear();
+    },
+  };
+}