Merge pull request 'Implement `self.structuredClone()`' (#2206) from FranklinDM/UXP-contrib:work_js-structuredclone into master

Reviewed-on: https://repo.palemoon.org/MoonchildProductions/UXP/pulls/2206

1 files changed, 69 insertions, 0 deletions

diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
index 990e1bc589..86e52984af 100644
--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -47,6 +47,7 @@
 #include "mozilla/dom/HTMLTemplateElement.h"
 #include "mozilla/dom/ipc/BlobChild.h"
 #include "mozilla/dom/ipc/BlobParent.h"
+#include "mozilla/dom/MessagePort.h"
 #include "mozilla/dom/Promise.h"
 #include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/dom/TabParent.h"
@@ -9991,3 +9992,71 @@ nsContentUtils::GetClosestNonNativeAnonymousAncestor(Element* aElement)
   }
   return e;
 }
+
+/* static */ nsresult
+nsContentUtils::CreateJSValueFromSequenceOfObject(JSContext* aCx,
+                                                  const Sequence<JSObject*>& aTransfer,
+                                                  JS::MutableHandle<JS::Value> aValue)
+{
+  if (aTransfer.IsEmpty()) {
+    return NS_OK;
+  }
+
+  JS::Rooted<JSObject*> array(aCx, JS_NewArrayObject(aCx, aTransfer.Length()));
+  if (!array) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  for (uint32_t i = 0; i < aTransfer.Length(); ++i) {
+    JS::Rooted<JSObject*> object(aCx, aTransfer[i]);
+    if (!object) {
+      continue;
+    }
+
+    if (NS_WARN_IF(!JS_DefineElement(aCx, array, i, object,
+                                     JSPROP_ENUMERATE))) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  }
+
+  aValue.setObject(*array);
+  return NS_OK;
+}
+
+/* static */
+void nsContentUtils::StructuredClone(JSContext* aCx,
+                                     nsIGlobalObject* aGlobal,
+                                     JS::Handle<JS::Value> aValue,
+                                     const StructuredSerializeOptions& aOptions,
+                                     JS::MutableHandle<JS::Value> aRv,
+                                     ErrorResult& aError) {
+  JS::Rooted<JS::Value> transferArray(aCx, JS::UndefinedValue());
+  aError = nsContentUtils::CreateJSValueFromSequenceOfObject(
+      aCx, aOptions.mTransfer, &transferArray);
+  if (NS_WARN_IF(aError.Failed())) {
+    return;
+  }
+
+  JS::CloneDataPolicy clonePolicy;
+  // FIXME: Uncomment once bug 1609990 and bug 1611855 lands.
+  //clonePolicy.allowIntraClusterClonableSharedObjects();
+  //clonePolicy.allowSharedMemoryObjects();
+
+  StructuredCloneHolder holder(StructuredCloneHolder::CloningSupported,
+                               StructuredCloneHolder::TransferringSupported,
+                               JS::StructuredCloneScope::SameProcessDifferentThread);
+  holder.Write(aCx, aValue, transferArray, clonePolicy, aError);
+  if (NS_WARN_IF(aError.Failed())) {
+    return;
+  }
+
+  // TODO: Pass clonePolicy.
+  //holder.Read(this, aCx, aRv, clonePolicy, aError);
+  holder.Read(aGlobal, aCx, aRv, aError);
+  if (NS_WARN_IF(aError.Failed())) {
+    return;
+  }
+
+  nsTArray<RefPtr<MessagePort>> ports = holder.TakeTransferredPorts();
+  Unused << ports;
+}