lib: convert transfer sequence to array in js

Author: jazelly

lib/internal/bootstrap/web/exposed-window-or-worker.js

@@ -38,8 +38,11 @@ const {
 } = require('internal/process/task_queues');
 defineOperation(globalThis, 'queueMicrotask', queueMicrotask);
 
-const { structuredClone } = internalBinding('messaging');
-defineOperation(globalThis, 'structuredClone', structuredClone);
+defineLazyProperties(
+  globalThis,
+  'internal/structured_clone',
+  ['structuredClone'],
+);
 defineLazyProperties(globalThis, 'buffer', ['atob', 'btoa']);
 
 // https://html.spec.whatwg.org/multipage/web-messaging.html#broadcasting-to-other-browsing-contexts

lib/internal/perf/usertiming.js

@@ -31,7 +31,7 @@ const {
   },
 } = require('internal/errors');
 
-const { structuredClone } = internalBinding('messaging');
+const { structuredClone } = require('internal/structured_clone');
 const {
   lazyDOMException,
   kEnumerableProperty,

lib/internal/structured_clone.js

@@ -0,0 +1,47 @@
+'use strict';
+
+const {
+  codes: {
+    ERR_INVALID_ARG_TYPE,
+    ERR_MISSING_ARGS,
+  },
+} = require('internal/errors');
+const webidl = require('internal/webidl');
+
+const {
+  structuredClone: nativeStructuredClone,
+} = internalBinding('messaging');
+
+webidl.converters['sequence<object>'] = webidl.createSequenceConverter(webidl.converters.any);
+
+function structuredClone(value, options) {
+  if (arguments.length === 0) {
+    throw new ERR_MISSING_ARGS('The value argument must be specified');
+  }
+
+  // TODO(jazelly): implement generic webidl dictionary converter
+  const prefix = 'Options';
+  const optionsType = webidl.type(options);
+  if (optionsType !== 'Undefined' && optionsType !== 'Null' && optionsType !== 'Object') {
+    throw new ERR_INVALID_ARG_TYPE(
+      prefix,
+      ['object', 'null', 'undefined'],
+      options,
+    );
+  }
+  const key = 'transfer';
+  const idlOptions = { __proto__: null, [key]: [] };
+  if (options !== undefined && options !== null && key in options && options[key] !== undefined) {
+    idlOptions[key] = webidl.converters['sequence<transfer>'](options[key], {
+      __proto__: null,
+      context: 'Transfer',
+    });
+  }
+
+  const serializedData = nativeStructuredClone(value, idlOptions);
+  return serializedData;
+}
+
+module.exports = {
+  structuredClone,
+};

lib/internal/webidl.js

@@ -38,6 +38,16 @@ converters.any = (V) => {
   return V;
 };
 
+converters.object = (V, opts = kEmptyObject) => {
+  if (type(V) !== 'Object') {
+    throw makeException(
+      'is not an object',
+      kEmptyObject,
+    );
+  }
+  return V;
+};
+
 // https://webidl.spec.whatwg.org/#abstract-opdef-integerpart
 const integerPart = MathTrunc;
 

lib/internal/webstreams/readablestream.js

@@ -88,7 +88,7 @@ const {
   kControllerErrorFunction,
 } = require('internal/streams/utils');
 
-const { structuredClone } = internalBinding('messaging');
+const { structuredClone } = require('internal/structured_clone');
 
 const {
   ArrayBufferViewGetBuffer,

src/node_messaging.cc

@@ -1578,28 +1578,21 @@ static void StructuredClone(const FunctionCallbackInfo<Value>& args) {
   Realm* realm = Realm::GetCurrent(context);
   Environment* env = realm->env();
 
-  if (args.Length() == 0) {
-    return THROW_ERR_MISSING_ARGS(env, "The value argument must be specified");
-  }
-
   Local<Value> value = args[0];
 
   TransferList transfer_list;
-  if (!args[1]->IsNullOrUndefined()) {
-    if (!args[1]->IsObject()) {
-      return THROW_ERR_INVALID_ARG_TYPE(
-          env, "The options argument must be either an object or undefined");
-    }
-    Local<Object> options = args[1].As<Object>();
-    Local<Value> transfer_list_v;
-    if (!options->Get(context, env->transfer_string())
-             .ToLocal(&transfer_list_v)) {
-      return;
-    }
+  Local<Object> options = args[1].As<Object>();
+  Local<Value> transfer_list_v;
+  if (!options->Get(context, env->transfer_string())
+            .ToLocal(&transfer_list_v)) {
+    return;
+  }
 
-    // TODO(joyeecheung): implement this in JS land to avoid the C++ -> JS
-    // cost to convert a sequence into an array.
-    if (!GetTransferList(env, context, transfer_list_v, &transfer_list)) {
+  Local<Array> arr = transfer_list_v.As<Array>();
+  size_t length = arr->Length();
+  transfer_list.AllocateSufficientStorage(length);
+  for (size_t i = 0; i < length; i++) {
+    if (!arr->Get(context, i).ToLocal(&transfer_list[i])) {
       return;
     }
   }

test/parallel/test-structuredClone-global.js

@@ -8,12 +8,12 @@ assert.throws(() => structuredClone(undefined, ''), { code: 'ERR_INVALID_ARG_TYP
 assert.throws(() => structuredClone(undefined, 1), { code: 'ERR_INVALID_ARG_TYPE' });
 assert.throws(() => structuredClone(undefined, { transfer: 1 }), { code: 'ERR_INVALID_ARG_TYPE' });
 assert.throws(() => structuredClone(undefined, { transfer: '' }), { code: 'ERR_INVALID_ARG_TYPE' });
+assert.throws(() => structuredClone(undefined, { transfer: null }), { code: 'ERR_INVALID_ARG_TYPE' });
 
 // Options can be null or undefined.
 assert.strictEqual(structuredClone(undefined), undefined);
 assert.strictEqual(structuredClone(undefined, null), undefined);
 // Transfer can be null or undefined.
-assert.strictEqual(structuredClone(undefined, { transfer: null }), undefined);
 assert.strictEqual(structuredClone(undefined, { }), undefined);
 
 // Transferables or its subclasses should be received with its closest transferable superclass
@@ -43,6 +43,27 @@ for (const Transferrable of [File, Blob]) {
   assert.ok(extendedTransfer instanceof Transferrable);
 }
 
+// Transfer can be iterable
+{
+  const value = {
+    a: new ReadableStream(),
+    b: new WritableStream(),
+  };
+  const cloned = structuredClone(value, {
+    transfer: {
+      *[Symbol.iterator]() {
+        for (const key in value) {
+          yield value[key];
+        }
+      }
+    }
+  });
+  for (const key in value) {
+    assert.ok(value[key].locked);
+    assert.ok(!cloned[key].locked);
+  }
+}
+
 {
   // See: https://github.com/nodejs/node/issues/49940
   const cloned = structuredClone({}, {