Exposing APIs to store/get host data

This is implemented by using internal property (EmbedderData). Currently
it is used for TypedArray/ArrayBuffer. It may expand in future.

lib/Jsrt/ChakraCore.h

@@ -1949,6 +1949,30 @@ CHAKRA_API
 JsExternalizeArrayBuffer(
     _In_ JsValueRef arrayBuffer);
 
+/// <summary>
+///     Get host embedded data from the current object
+/// </summary>
+/// <param name="instance">Js object from which an embedder data to be fetched</param>
+/// <param name="embedderData">An embedder data to be returned, it will be nullptr if not found</param>
+/// <returns>
+///     The code <c>JsNoError</c> if the operation succeeded, a failure code
+///     otherwise.
+/// </returns>
+CHAKRA_API
+JsGetEmbedderData(_In_ JsValueRef instance, _Out_ JsValueRef* embedderData);
+
+/// <summary>
+///     Set host embedded data on the current object
+/// </summary>
+/// <param name="instance">Js object from which an embedder data to be fetched</param>
+/// <param name="embedderData">An embedder data to be set on the passed object</param>
+/// <returns>
+///     The code <c>JsNoError</c> if the operation succeeded, a failure code
+///     otherwise.
+/// </returns>
+CHAKRA_API
+JsSetEmbedderData(_In_ JsValueRef instance, _In_ JsValueRef embedderData);
+
 #ifdef _WIN32
 #include "ChakraCoreWindows.h"
 #endif // _WIN32

lib/Jsrt/Core/JsrtCore.cpp

@@ -497,6 +497,63 @@ JsSetArrayBufferExtraInfo(
     END_JSRT_NO_EXCEPTION
 }
 
+
+CHAKRA_API
+JsGetEmbedderData(
+    _In_ JsValueRef instance,
+    _Out_ JsValueRef* embedderData)
+{
+   VALIDATE_JSREF(instance);
+   PARAM_NOT_NULL(embedderData);
+   return ContextAPINoScriptWrapper_NoRecord([&](Js::ScriptContext* scriptContext) -> JsErrorCode {
+        Js::RecyclableObject* object = Js::JavascriptOperators::TryFromVar<Js::RecyclableObject>(instance);
+        if (!object)
+        {
+            return JsErrorInvalidArgument;
+        }
+
+        // Right now we know that we support these many. Lets find out if
+        // there are more.
+        Assert(Js::TypedArrayBase::Is(object->GetTypeId()) ||
+               object->GetTypeId() == Js::TypeIds_ArrayBuffer ||
+               object->GetTypeId() == Js::TypeIds_DataView ||
+               object->GetTypeId() == Js::TypeIds_SharedArrayBuffer);
+
+        if (!object->GetInternalProperty(object, Js::InternalPropertyIds::EmbedderData, embedderData, nullptr, scriptContext))
+        {
+            *embedderData = nullptr;
+        }
+        return JsNoError;
+    });
+}
+
+CHAKRA_API
+JsSetEmbedderData(_In_ JsValueRef instance, _In_ JsValueRef embedderData)
+{
+   VALIDATE_JSREF(instance);
+   return ContextAPINoScriptWrapper_NoRecord([&](Js::ScriptContext* scriptContext) -> JsErrorCode {
+        Js::RecyclableObject* object = Js::JavascriptOperators::TryFromVar<Js::RecyclableObject>(instance);
+        if (!object)
+        {
+            return JsErrorInvalidArgument;
+        }
+
+        // Right now we know that we support these many. Lets find out if
+        // there are more.
+        Assert(Js::TypedArrayBase::Is(object->GetTypeId()) ||
+               object->GetTypeId() == Js::TypeIds_ArrayBuffer ||
+               object->GetTypeId() == Js::TypeIds_DataView ||
+               object->GetTypeId() == Js::TypeIds_SharedArrayBuffer);
+
+        if (!object->SetInternalProperty(Js::InternalPropertyIds::EmbedderData, embedderData, Js::PropertyOperationFlags::PropertyOperation_None, nullptr))
+        {
+           return JsErrorInvalidArgument;
+        }
+
+        return JsNoError;
+    });
+}
+
 CHAKRA_API
 JsExternalizeArrayBuffer(
     _In_ JsValueRef arrayBufferVar)

lib/Jsrt/JsrtCommonExports.inc

@@ -134,6 +134,8 @@
     JsGetIteratorPrototype
     JsGetPropertyIdSymbolIterator
     JsGetWeakReferenceValue
+    JsGetEmbedderData
+    JsSetEmbedderData
     JsHasOwnProperty
     JsHasOwnItem
     JsIsCallable

lib/Runtime/InternalPropertyList.h

@@ -26,4 +26,6 @@ INTERNALPROPERTY(CachedUDateFormat)               // Used to store cached UDateF
 INTERNALPROPERTY(CachedUPluralRules)              // Used to store cached UPluralRules objects for Intl.PluralRules
 INTERNALPROPERTY(RevocableProxy)                  // Internal slot for [[RevokableProxy]] for revocable proxy in ES6
 INTERNALPROPERTY(MutationBp)                      // Used to store strong reference to the mutation breakpoint object
+INTERNALPROPERTY(EmbedderData)                    // Holds embedder data here.
+
 #undef INTERNALPROPERTY

lib/Runtime/Types/DynamicObject.cpp

@@ -809,6 +809,16 @@ namespace Js
             mutationBpValue = nullptr;
         }
 
+        Var embedderData = nullptr;
+        if (this->GetInternalProperty(this, InternalPropertyIds::EmbedderData,  &embedderData, nullptr, this->GetScriptContext()))
+        {
+          this->SetInternalProperty(InternalPropertyIds::EmbedderData, nullptr, PropertyOperation_Force, nullptr);
+        }
+        else
+        {
+          embedderData = nullptr;
+        }
+
         // If value of TypeOfPrototypeObjectDictionary was set undefined above, reset it to nullptr so we don't type cast it wrongly to TypeTransitionMap* or we don't marshal the non-Var dictionary below
         Var typeTransitionMap = nullptr;
         if (this->GetInternalProperty(this, InternalPropertyIds::TypeOfPrototypeObjectDictionary, &typeTransitionMap, nullptr, this->GetScriptContext()))
@@ -832,6 +842,10 @@ namespace Js
             {
                 this->SetInternalProperty(InternalPropertyIds::MutationBp, mutationBpValue, PropertyOperation_Force, nullptr);
             }
+            if (embedderData)
+            {
+              this->SetInternalProperty(InternalPropertyIds::EmbedderData, embedderData, PropertyOperation_Force, nullptr);
+            }
         }
     }