update

src/utils/batch/ObservableTask.ts

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+/**
+ * This file is licensed under MIT license, not AGPL.
+ *
+ * Copyright (c) 2023 Syusui Moyatani
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+import nextId from './nextId';
+
+export default class ObservableTask<BatchRequest, BatchResponse> {
+  id: number;
+
+  req: BatchRequest;
+
+  res: BatchResponse | undefined;
+
+  isCompleted = false;
+
+  #updateListeners: ((res: BatchResponse) => void)[] = [];
+
+  #completeListeners: (() => void)[] = [];
+
+  #promise: Promise<BatchResponse>;
+
+  constructor(req: BatchRequest) {
+    this.id = nextId();
+    this.req = req;
+    this.#promise = new Promise((resolve, reject) => {
+      this.onComplete(() => {
+        if (this.res != null) {
+          resolve(this.res);
+        } else {
+          reject();
+        }
+      });
+    });
+  }
+
+  #executeUpdateListeners() {
+    const { res } = this;
+    if (res != null) {
+      this.#updateListeners.forEach((listener) => {
+        listener(res);
+      });
+    }
+  }
+
+  update(res: BatchResponse) {
+    this.res = res;
+    this.#executeUpdateListeners();
+  }
+
+  updateWith(f: (current: BatchResponse | undefined) => BatchResponse) {
+    this.res = f(this.res);
+    this.#executeUpdateListeners();
+  }
+
+  complete() {
+    this.isCompleted = true;
+    this.#completeListeners.forEach((listener) => {
+      listener();
+    });
+  }
+
+  onUpdate(f: (res: BatchResponse) => void) {
+    this.#updateListeners.push(f);
+  }
+
+  // alias for onUpdate.
+  subscribe(fn: (v: BatchResponse) => void) {
+    this.onUpdate(fn);
+  }
+
+  onComplete(f: () => void) {
+    this.#completeListeners.push(f);
+  }
+
+  toPromise(): Promise<BatchResponse> {
+    return this.#promise;
+  }
+}