🤖 Merge PR DefinitelyTyped#68264 [@types/node] Update v8 type definitions by @codershiba

Author: codershiba

types/node/test/v8.ts

@@ -1,5 +1,7 @@
+import * as assert from "node:assert";
 import { Readable } from "node:stream";
 import * as v8 from "node:v8";
+import * as zlib from "node:zlib";
 
 const heapStats = v8.getHeapStatistics();
 const numOfDetached = heapStats.number_of_detached_contexts;
@@ -34,3 +36,39 @@ const stopInit = v8.promiseHooks.onInit((promise, parent) => {});
 const stopBefore = v8.promiseHooks.onBefore(promise => {});
 const stopAfter = v8.promiseHooks.onAfter(promise => {});
 const stopSettled = v8.promiseHooks.onSettled(promise => {});
+
+class BookShelf {
+    storage: Map<string, Buffer | string> = new Map();
+
+    constructor(bookNames: string[]) {
+        for (const bookName of bookNames) {
+            this.storage.set(bookName, bookName);
+        }
+    }
+
+    static compressAll(shelf: BookShelf): void {
+        for (const [book, content] of shelf.storage) {
+            shelf.storage.set(book, zlib.gzipSync(content));
+        }
+    }
+
+    static decompressAll(shelf: BookShelf): void {
+        for (const [book, content] of shelf.storage) {
+            shelf.storage.set(book, zlib.gunzipSync(content));
+        }
+    }
+}
+
+const bookNames = ["book1.en_US", "book1.es_ES", "book2.zh_CN"];
+
+const shelf = new BookShelf(bookNames);
+
+assert(v8.startupSnapshot.isBuildingSnapshot());
+v8.startupSnapshot.addSerializeCallback(BookShelf.compressAll, shelf);
+v8.startupSnapshot.addDeserializeCallback(BookShelf.decompressAll, shelf);
+v8.startupSnapshot.setDeserializeMainFunction((shelf: BookShelf): void => {
+    const lang = "en_US";
+    const book = process.argv[1];
+    const name = `${book}.${lang}`;
+    console.log(shelf.storage.get(name));
+}, shelf);

types/node/ts4.8/test/v8.ts

@@ -1,5 +1,7 @@
+import * as assert from "node:assert";
 import { Readable } from "node:stream";
 import * as v8 from "node:v8";
+import * as zlib from "node:zlib";
 
 const heapStats = v8.getHeapStatistics();
 const numOfDetached = heapStats.number_of_detached_contexts;
@@ -34,3 +36,39 @@ const stopInit = v8.promiseHooks.onInit((promise, parent) => {});
 const stopBefore = v8.promiseHooks.onBefore(promise => {});
 const stopAfter = v8.promiseHooks.onAfter(promise => {});
 const stopSettled = v8.promiseHooks.onSettled(promise => {});
+
+class BookShelf {
+    storage: Map<string, Buffer | string> = new Map();
+
+    constructor(bookNames: string[]) {
+        for (const bookName of bookNames) {
+            this.storage.set(bookName, bookName);
+        }
+    }
+
+    static compressAll(shelf: BookShelf): void {
+        for (const [book, content] of shelf.storage) {
+            shelf.storage.set(book, zlib.gzipSync(content));
+        }
+    }
+
+    static decompressAll(shelf: BookShelf): void {
+        for (const [book, content] of shelf.storage) {
+            shelf.storage.set(book, zlib.gunzipSync(content));
+        }
+    }
+}
+
+const bookNames = ["book1.en_US", "book1.es_ES", "book2.zh_CN"];
+
+const shelf = new BookShelf(bookNames);
+
+assert(v8.startupSnapshot.isBuildingSnapshot());
+v8.startupSnapshot.addSerializeCallback(BookShelf.compressAll, shelf);
+v8.startupSnapshot.addDeserializeCallback(BookShelf.decompressAll, shelf);
+v8.startupSnapshot.setDeserializeMainFunction((shelf: BookShelf): void => {
+    const lang = "en_US";
+    const book = process.argv[1];
+    const name = `${book}.${lang}`;
+    console.log(shelf.storage.get(name));
+}, shelf);

types/node/ts4.8/v8.d.ts

@@ -4,7 +4,7 @@
  * ```js
  * const v8 = require('node:v8');
  * ```
- * @see [source](https://github.com/nodejs/node/blob/v20.2.0/lib/v8.js)
+ * @see [source](https://github.com/nodejs/node/blob/v20.11.0/lib/v8.js)
  */
 declare module "v8" {
     import { Readable } from "node:stream";
@@ -38,6 +38,18 @@ declare module "v8" {
         bytecode_and_metadata_size: number;
         external_script_source_size: number;
     }
+    interface HeapSnapshotOptions {
+        /**
+         * If true, expose internals in the heap snapshot.
+         * @default false
+         */
+        exposeInternals?: boolean;
+        /**
+         * If true, expose numeric values in artificial fields.
+         * @default false
+         */
+        exposeNumericValues?: boolean;
+    }
     /**
      * Returns an integer representing a version tag derived from the V8 version,
      * command-line flags, and detected CPU features. This is useful for determining
@@ -105,7 +117,7 @@ declare module "v8" {
      * Returns statistics about the V8 heap spaces, i.e. the segments which make up
      * the V8 heap. Neither the ordering of heap spaces, nor the availability of a
      * heap space can be guaranteed as the statistics are provided via the
-     * V8[`GetHeapSpaceStatistics`](https://v8docs.nodesource.com/node-13.2/d5/dda/classv8_1_1_isolate.html#ac673576f24fdc7a33378f8f57e1d13a4) function and may change from one V8 version to the
+     * V8 [`GetHeapSpaceStatistics`](https://v8docs.nodesource.com/node-13.2/d5/dda/classv8_1_1_isolate.html#ac673576f24fdc7a33378f8f57e1d13a4) function and may change from one V8 version to the
      * next.
      *
      * The value returned is an array of objects containing the following properties:
@@ -194,7 +206,7 @@ declare module "v8" {
      * @since v11.13.0
      * @return A Readable containing the V8 heap snapshot.
      */
-    function getHeapSnapshot(): Readable;
+    function getHeapSnapshot(options?: HeapSnapshotOptions): Readable;
     /**
      * Generates a snapshot of the current V8 heap and writes it to a JSON
      * file. This file is intended to be used with tools such as Chrome
@@ -246,10 +258,10 @@ declare module "v8" {
      * worker thread.
      * @return The filename where the snapshot was saved.
      */
-    function writeHeapSnapshot(filename?: string): string;
+    function writeHeapSnapshot(filename?: string, options?: HeapSnapshotOptions): string;
     /**
      * Get statistics about code and its metadata in the heap, see
-     * V8[`GetHeapCodeAndMetadataStatistics`](https://v8docs.nodesource.com/node-13.2/d5/dda/classv8_1_1_isolate.html#a6079122af17612ef54ef3348ce170866) API. Returns an object with the
+     * V8 [`GetHeapCodeAndMetadataStatistics`](https://v8docs.nodesource.com/node-13.2/d5/dda/classv8_1_1_isolate.html#a6079122af17612ef54ef3348ce170866) API. Returns an object with the
      * following properties:
      *
      * ```js
@@ -408,6 +420,13 @@ declare module "v8" {
      * @since v15.1.0, v14.18.0, v12.22.0
      */
     function stopCoverage(): void;
+    /**
+     * The API is a no-op if `--heapsnapshot-near-heap-limit` is already set from the command line or the API is called more than once.
+     * `limit` must be a positive integer. See [`--heapsnapshot-near-heap-limit`](https://nodejs.org/docs/latest-v20.x/api/cli.html#--heapsnapshot-near-heap-limitmax_count) for more information.
+     * @experimental
+     * @since v18.10.0, v16.18.0
+     */
+    function setHeapSnapshotNearHeapLimit(limit: number): void;
     /**
      * This API collects GC data in current thread.
      * @since v19.6.0, v18.15.0
@@ -629,6 +648,116 @@ declare module "v8" {
      * @since v17.1.0, v16.14.0
      */
     const promiseHooks: PromiseHooks;
+    type StartupSnapshotCallbackFn = (args: any) => any;
+    interface StartupSnapshot {
+        /**
+         * Add a callback that will be called when the Node.js instance is about to get serialized into a snapshot and exit.
+         * This can be used to release resources that should not or cannot be serialized or to convert user data into a form more suitable for serialization.
+         * @since v18.6.0, v16.17.0
+         */
+        addSerializeCallback(callback: StartupSnapshotCallbackFn, data?: any): void;
+        /**
+         * Add a callback that will be called when the Node.js instance is deserialized from a snapshot.
+         * The `callback` and the `data` (if provided) will be serialized into the snapshot, they can be used to re-initialize the state of the application or
+         * to re-acquire resources that the application needs when the application is restarted from the snapshot.
+         * @since v18.6.0, v16.17.0
+         */
+        addDeserializeCallback(callback: StartupSnapshotCallbackFn, data?: any): void;
+        /**
+         * This sets the entry point of the Node.js application when it is deserialized from a snapshot. This can be called only once in the snapshot building script.
+         * If called, the deserialized application no longer needs an additional entry point script to start up and will simply invoke the callback along with the deserialized
+         * data (if provided), otherwise an entry point script still needs to be provided to the deserialized application.
+         * @since v18.6.0, v16.17.0
+         */
+        setDeserializeMainFunction(callback: StartupSnapshotCallbackFn, data?: any): void;
+        /**
+         * Returns true if the Node.js instance is run to build a snapshot.
+         * @since v18.6.0, v16.17.0
+         */
+        isBuildingSnapshot(): boolean;
+    }
+    /**
+     * The `v8.startupSnapshot` interface can be used to add serialization and deserialization hooks for custom startup snapshots.
+     *
+     * ```bash
+     * $ node --snapshot-blob snapshot.blob --build-snapshot entry.js
+     * # This launches a process with the snapshot
+     * $ node --snapshot-blob snapshot.blob
+     * ```
+     *
+     * In the example above, `entry.js` can use methods from the `v8.startupSnapshot` interface to specify how to save information for custom objects
+     * in the snapshot during serialization and how the information can be used to synchronize these objects during deserialization of the snapshot.
+     * For example, if the `entry.js` contains the following script:
+     *
+     * ```js
+     * 'use strict';
+     *
+     * const fs = require('node:fs');
+     * const zlib = require('node:zlib');
+     * const path = require('node:path');
+     * const assert = require('node:assert');
+     *
+     * const v8 = require('node:v8');
+     *
+     * class BookShelf {
+     *   storage = new Map();
+     *
+     *   // Reading a series of files from directory and store them into storage.
+     *   constructor(directory, books) {
+     *     for (const book of books) {
+     *       this.storage.set(book, fs.readFileSync(path.join(directory, book)));
+     *     }
+     *   }
+     *
+     *   static compressAll(shelf) {
+     *     for (const [ book, content ] of shelf.storage) {
+     *       shelf.storage.set(book, zlib.gzipSync(content));
+     *     }
+     *   }
+     *
+     *   static decompressAll(shelf) {
+     *     for (const [ book, content ] of shelf.storage) {
+     *       shelf.storage.set(book, zlib.gunzipSync(content));
+     *     }
+     *   }
+     * }
+     *
+     * // __dirname here is where the snapshot script is placed
+     * // during snapshot building time.
+     * const shelf = new BookShelf(__dirname, [
+     *   'book1.en_US.txt',
+     *   'book1.es_ES.txt',
+     *   'book2.zh_CN.txt',
+     * ]);
+     *
+     * assert(v8.startupSnapshot.isBuildingSnapshot());
+     * // On snapshot serialization, compress the books to reduce size.
+     * v8.startupSnapshot.addSerializeCallback(BookShelf.compressAll, shelf);
+     * // On snapshot deserialization, decompress the books.
+     * v8.startupSnapshot.addDeserializeCallback(BookShelf.decompressAll, shelf);
+     * v8.startupSnapshot.setDeserializeMainFunction((shelf) => {
+     *   // process.env and process.argv are refreshed during snapshot
+     *   // deserialization.
+     *   const lang = process.env.BOOK_LANG || 'en_US';
+     *   const book = process.argv[1];
+     *   const name = `${book}.${lang}.txt`;
+     *   console.log(shelf.storage.get(name));
+     * }, shelf);
+     * ```
+     *
+     * The resulted binary will get print the data deserialized from the snapshot during start up, using the refreshed `process.env` and `process.argv` of the launched process:
+     *
+     * ```bash
+     * $ BOOK_LANG=es_ES node --snapshot-blob snapshot.blob book1
+     * # Prints content of book1.es_ES.txt deserialized from the snapshot.
+     * ```
+     *
+     * Currently the application deserialized from a user-land snapshot cannot be snapshotted again, so these APIs are only available to applications that are not deserialized from a user-land snapshot.
+     *
+     * @experimental
+     * @since v18.6.0, v16.17.0
+     */
+    const startupSnapshot: StartupSnapshot;
 }
 declare module "node:v8" {
     export * from "v8";

types/node/v16/test/v8.ts

@@ -1,5 +1,7 @@
+import * as assert from "node:assert";
 import { Readable } from "node:stream";
 import * as v8 from "node:v8";
+import * as zlib from "node:zlib";
 
 const heapStats = v8.getHeapStatistics();
 const numOfDetached = heapStats.number_of_detached_contexts;
@@ -26,3 +28,39 @@ const stopInit = v8.promiseHooks.onInit((promise, parent) => {});
 const stopBefore = v8.promiseHooks.onBefore(promise => {});
 const stopAfter = v8.promiseHooks.onAfter(promise => {});
 const stopSettled = v8.promiseHooks.onSettled(promise => {});
+
+class BookShelf {
+    storage: Map<string, Buffer | string> = new Map();
+
+    constructor(bookNames: string[]) {
+        for (const bookName of bookNames) {
+            this.storage.set(bookName, bookName);
+        }
+    }
+
+    static compressAll(shelf: BookShelf): void {
+        for (const [book, content] of shelf.storage) {
+            shelf.storage.set(book, zlib.gzipSync(content));
+        }
+    }
+
+    static decompressAll(shelf: BookShelf): void {
+        for (const [book, content] of shelf.storage) {
+            shelf.storage.set(book, zlib.gunzipSync(content));
+        }
+    }
+}
+
+const bookNames = ["book1.en_US", "book1.es_ES", "book2.zh_CN"];
+
+const shelf = new BookShelf(bookNames);
+
+assert(v8.startupSnapshot.isBuildingSnapshot());
+v8.startupSnapshot.addSerializeCallback(BookShelf.compressAll, shelf);
+v8.startupSnapshot.addDeserializeCallback(BookShelf.decompressAll, shelf);
+v8.startupSnapshot.setDeserializeMainFunction((shelf: BookShelf): void => {
+    const lang = "en_US";
+    const book = process.argv[1];
+    const name = `${book}.${lang}`;
+    console.log(shelf.storage.get(name));
+}, shelf);

types/node/v16/ts4.8/test/v8.ts

@@ -1,5 +1,7 @@
+import * as assert from "node:assert";
 import { Readable } from "node:stream";
 import * as v8 from "node:v8";
+import * as zlib from "node:zlib";
 
 const heapStats = v8.getHeapStatistics();
 const numOfDetached = heapStats.number_of_detached_contexts;
@@ -26,3 +28,39 @@ const stopInit = v8.promiseHooks.onInit((promise, parent) => {});
 const stopBefore = v8.promiseHooks.onBefore(promise => {});
 const stopAfter = v8.promiseHooks.onAfter(promise => {});
 const stopSettled = v8.promiseHooks.onSettled(promise => {});
+
+class BookShelf {
+    storage: Map<string, Buffer | string> = new Map();
+
+    constructor(bookNames: string[]) {
+        for (const bookName of bookNames) {
+            this.storage.set(bookName, bookName);
+        }
+    }
+
+    static compressAll(shelf: BookShelf): void {
+        for (const [book, content] of shelf.storage) {
+            shelf.storage.set(book, zlib.gzipSync(content));
+        }
+    }
+
+    static decompressAll(shelf: BookShelf): void {
+        for (const [book, content] of shelf.storage) {
+            shelf.storage.set(book, zlib.gunzipSync(content));
+        }
+    }
+}
+
+const bookNames = ["book1.en_US", "book1.es_ES", "book2.zh_CN"];
+
+const shelf = new BookShelf(bookNames);
+
+assert(v8.startupSnapshot.isBuildingSnapshot());
+v8.startupSnapshot.addSerializeCallback(BookShelf.compressAll, shelf);
+v8.startupSnapshot.addDeserializeCallback(BookShelf.decompressAll, shelf);
+v8.startupSnapshot.setDeserializeMainFunction((shelf: BookShelf): void => {
+    const lang = "en_US";
+    const book = process.argv[1];
+    const name = `${book}.${lang}`;
+    console.log(shelf.storage.get(name));
+}, shelf);