hls service and controller

server/src/utils/event.ts

@@ -0,0 +1,44 @@
+import { ArgOf, EmitEvent } from 'src/repositories/event.repository';
+
+export class PendingEvents<T extends { [T in EmitEvent]: ArgOf<T> extends { error?: string } ? T : never }[EmitEvent]> {
+  private pending = new Map<string, { completers: PromiseWithResolvers<ArgOf<T>>[]; timeout: NodeJS.Timeout }>();
+
+  constructor(private timeoutMs: number) {}
+
+  wait(key: string): Promise<ArgOf<T>> {
+    const completer = Promise.withResolvers<ArgOf<T>>();
+    const existing = this.pending.get(key);
+    if (existing) {
+      existing.completers.push(completer);
+      return completer.promise;
+    }
+
+    const timeout = setTimeout(() => this.complete(key, { error: 'Request timed out' }), this.timeoutMs);
+    this.pending.set(key, { completers: [completer], timeout });
+    return completer.promise;
+  }
+
+  complete(key: string, value: ArgOf<T> | { error: string }) {
+    const pending = this.pending.get(key);
+    if (!pending) {
+      return;
+    }
+    clearTimeout(pending.timeout);
+    this.pending.delete(key);
+    for (const completer of pending.completers) {
+      if ('error' in value) {
+        completer.reject(new Error(value.error));
+      } else {
+        completer.resolve(value);
+      }
+    }
+  }
+
+  rejectByPrefix(prefix: string, error: string) {
+    for (const key of this.pending.keys()) {
+      if (key.startsWith(prefix)) {
+        this.complete(key, { error });
+      }
+    }
+  }
+}