chore: import upstream snapshot with attribution

extensions/ipynb/src/notebookSerializer.web.ts

@@ -0,0 +1,85 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+import { DeferredPromise, generateUuid } from './helper';
+import { NotebookSerializerBase } from './notebookSerializer';
+
+export class NotebookSerializer extends NotebookSerializerBase {
+	private experimentalSave = vscode.workspace.getConfiguration('ipynb').get('experimental.serialization', false);
+	private worker?: Worker;
+	private tasks = new Map<string, DeferredPromise<Uint8Array>>();
+
+	constructor(context: vscode.ExtensionContext) {
+		super(context);
+		context.subscriptions.push(vscode.workspace.onDidChangeConfiguration(e => {
+			if (e.affectsConfiguration('ipynb.experimental.serialization')) {
+				this.experimentalSave = vscode.workspace.getConfiguration('ipynb').get('experimental.serialization', false);
+			}
+		}));
+	}
+
+	override dispose() {
+		try {
+			void this.worker?.terminate();
+		} catch {
+			//
+		}
+		super.dispose();
+	}
+
+	public override async serializeNotebook(data: vscode.NotebookData, token: vscode.CancellationToken): Promise<Uint8Array> {
+		if (this.disposed) {
+			return new Uint8Array(0);
+		}
+
+		if (this.experimentalSave) {
+			return this.serializeViaWorker(data);
+		}
+
+		return super.serializeNotebook(data, token);
+	}
+
+	private async startWorker() {
+		if (this.disposed) {
+			throw new Error('Serializer disposed');
+		}
+		if (this.worker) {
+			return this.worker;
+		}
+		const entry = vscode.Uri.joinPath(this.context.extensionUri, 'dist', 'browser', 'notebookSerializerWorker.js');
+		this.worker = new Worker(entry.toString());
+		this.worker.addEventListener('exit', (exitCode) => {
+			if (!this.disposed) {
+				console.error(`IPynb Notebook Serializer Worker exited unexpectedly`, exitCode);
+			}
+			this.worker = undefined;
+		});
+		this.worker.onmessage = (e) => {
+			const result = e.data as { id: string; data: Uint8Array };
+			const task = this.tasks.get(result.id);
+			if (task) {
+				task.complete(result.data);
+				this.tasks.delete(result.id);
+			}
+		};
+		this.worker.onerror = (err) => {
+			if (!this.disposed) {
+				console.error(`IPynb Notebook Serializer Worker errored unexpectedly`, err);
+			}
+		};
+		return this.worker;
+	}
+	private async serializeViaWorker(data: vscode.NotebookData): Promise<Uint8Array> {
+		const worker = await this.startWorker();
+		const id = generateUuid();
+
+		const deferred = new DeferredPromise<Uint8Array>();
+		this.tasks.set(id, deferred);
+		worker.postMessage({ data, id });
+
+		return deferred.p;
+	}
+}