[serializer] introduce API to serialize internal fields

include/v8.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 6223 matching lines @@
   /**
    * Returns the number of wrappers that are still to be traced by the embedder.
    */
   virtual size_t NumberOfWrappersToTrace() { return 0; }
 
  protected:
   virtual ~EmbedderHeapTracer() = default;
 };
 
 /**
+ * Callback to the embedder used in SnapshotCreator to handle internal fields.
+ */
+typedef StartupData (*SerializeInternalFieldsCallback)(Local<Object> holder,
+                                                       int index);

[jochen (gone - plz use gerrit), 2016/10/27 12:40:51]

size_t ?

[Yang, 2016/10/27 12:49:27]

v8::Object::SetInternalField uses int, so I'd like to use the same type.

+
+/**
+ * Callback to the embedder used to deserialize internal fields.
+ */
+typedef void (*DeserializeInternalFieldsCallback)(Local<Object> holder,
+                                                  int index,
+                                                  StartupData payload);
+
+/**
  * Isolate represents an isolated instance of the V8 engine.  V8 isolates have
  * completely separate states.  Objects from one isolate must not be used in
  * other isolates.  The embedder can create multiple isolates and use them in
  * parallel in multiple threads.  An isolate can be entered by at most one
  * thread at any given time.  The Locker/Unlocker API must be used to
  * synchronize.
  */
 class V8_EXPORT Isolate {
  public:
   /**
    * Initial configuration parameters for a new Isolate.
    */
   struct CreateParams {
     CreateParams()
         : entry_hook(nullptr),
           code_event_handler(nullptr),
           snapshot_blob(nullptr),
           counter_lookup_callback(nullptr),
           create_histogram_callback(nullptr),
           add_histogram_sample_callback(nullptr),
           array_buffer_allocator(nullptr),
-          external_references(nullptr) {}
+          external_references(nullptr),
+          deserialize_internal_fields_callback(nullptr) {}
 
     /**
      * The optional entry_hook allows the host application to provide the
      * address of a function that's invoked on entry to every V8-generated
      * function.  Note that entry_hook is invoked at the very start of each
      * generated function. Furthermore, if an entry_hook is given, V8 will
      * not use a snapshot, including custom snapshots.
      */
     FunctionEntryHook entry_hook;
 
@@ skipping 35 matching lines @@
      */
     ArrayBuffer::Allocator* array_buffer_allocator;
 
     /**
      * Specifies an optional nullptr-terminated array of raw addresses in the
      * embedder that V8 can match against during serialization and use for
      * deserialization. This array and its content must stay valid for the
      * entire lifetime of the isolate.
      */
     intptr_t* external_references;
+
+    /**
+     * Specifies an optional callback to deserialize internal fields. It
+     * should match the SerializeInternalFieldCallback used to serialize.
+     */
+    DeserializeInternalFieldsCallback deserialize_internal_fields_callback;
   };
 
 
   /**
    * Stack-allocated class which sets the isolate for all operations
    * executed within a local scope.
    */
   class V8_EXPORT Scope {
    public:
     explicit Scope(Isolate* isolate) : isolate_(isolate) {
@@ skipping 1245 matching lines @@
    * Add a template to be included in the snapshot blob.
    * \returns the index of the template in the snapshot blob.
    */
   size_t AddTemplate(Local<Template> template_obj);
 
   /**
    * Created a snapshot data blob.
    * This must not be called from within a handle scope.
    * \param function_code_handling whether to include compiled function code
    *        in the snapshot.
+   * \param callback to serialize embedder-set internal fields.
    * \returns { nullptr, 0 } on failure, and a startup snapshot on success. The
    *        caller acquires ownership of the data array in the return value.
    */
-  StartupData CreateBlob(FunctionCodeHandling function_code_handling);
+  StartupData CreateBlob(FunctionCodeHandling function_code_handling,
+                         SerializeInternalFieldsCallback callback = nullptr);
 
   // Disallow copying and assigning.
   SnapshotCreator(const SnapshotCreator&) = delete;
   void operator=(const SnapshotCreator&) = delete;
 
  private:
   void* data_;
 };
 
 /**
@@ skipping 2067 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // INCLUDE_V8_H_