feat: store library to IndexedDB & support storage adapters (#7655)

packages/excalidraw/queue.ts

@@ -0,0 +1,45 @@
+import { MaybePromise } from "./utility-types";
+import { promiseTry, ResolvablePromise, resolvablePromise } from "./utils";
+
+type Job<T, TArgs extends unknown[]> = (...args: TArgs) => MaybePromise<T>;
+
+type QueueJob<T, TArgs extends unknown[]> = {
+  jobFactory: Job<T, TArgs>;
+  promise: ResolvablePromise<T>;
+  args: TArgs;
+};
+
+export class Queue {
+  private jobs: QueueJob<any, any[]>[] = [];
+  private running = false;
+
+  private tick() {
+    if (this.running) {
+      return;
+    }
+    const job = this.jobs.shift();
+    if (job) {
+      this.running = true;
+      job.promise.resolve(
+        promiseTry(job.jobFactory, ...job.args).finally(() => {
+          this.running = false;
+          this.tick();
+        }),
+      );
+    } else {
+      this.running = false;
+    }
+  }
+
+  push<TValue, TArgs extends unknown[]>(
+    jobFactory: Job<TValue, TArgs>,
+    ...args: TArgs
+  ): Promise<TValue> {
+    const promise = resolvablePromise<TValue>();
+    this.jobs.push({ jobFactory, promise, args });
+
+    this.tick();
+
+    return promise;
+  }
+}