[Bindings] Create and use V8 context snapshots

third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h

Index: third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h
diff --git a/third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h b/third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h
index 8af0f25c01ae503b222213bf66bf7fabf2d31bc4..ed069706809da727df5a1a43632c6be8f2931859 100644
--- a/third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h
+++ b/third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h
@@ -60,6 +60,12 @@ class PLATFORM_EXPORT V8PerIsolateData {
   WTF_MAKE_NONCOPYABLE(V8PerIsolateData);
 
  public:
+  enum class V8ContextSnapshotMode {
+    kTakeSnapshot,
+    kDontUseSnapshot,
+    kUseSnapshot,
+  };
+
   class EndOfScopeTask {
     USING_FAST_MALLOC(EndOfScopeTask);
 
@@ -101,7 +107,9 @@ class PLATFORM_EXPORT V8PerIsolateData {
     virtual ~Data() = default;
   };
 
-  static v8::Isolate* Initialize(WebTaskRunner*);
+  static v8::Isolate* Initialize(WebTaskRunner*,
+                                 intptr_t* refernce_table,
+                                 V8ContextSnapshotMode);
 
   static V8PerIsolateData* From(v8::Isolate* isolate) {
     DCHECK(isolate);
@@ -144,6 +152,17 @@ class PLATFORM_EXPORT V8PerIsolateData {
                             const void* key,
                             v8::Local<v8::FunctionTemplate>);
 
+  // When v8::SnapshotCreator::CreateBlob() is called, we must not have
+  // persistent handles in Blink. This method clears them.
+  void ClearPersistentsForV8ContextSnapshot();
+
+  v8::SnapshotCreator* GetSnapshotCreator() const {
+    return isolate_holder_.snapshot_creator();
+  }
+  V8ContextSnapshotMode GetV8ContextSnapshotMode() const {
+    return v8_context_snapshot_mode_;
+  }
+
   // Accessor to the cache of cross-origin accessible operation's templates.
   // Created templates get automatically cached.
   v8::Local<v8::FunctionTemplate> FindOrCreateOperationTemplate(
@@ -224,11 +243,14 @@ class PLATFORM_EXPORT V8PerIsolateData {
   }
 
  private:
-  explicit V8PerIsolateData(WebTaskRunner*);
+  V8PerIsolateData(WebTaskRunner*,
+                   intptr_t* reference_table,
+                   V8ContextSnapshotMode);
+  explicit V8PerIsolateData(intptr_t* reference_table);
   ~V8PerIsolateData();
 
-  typedef HashMap<const void*, v8::Eternal<v8::FunctionTemplate>>
-      V8FunctionTemplateMap;
+  using V8FunctionTemplateMap =
+      HashMap<const void*, v8::Eternal<v8::FunctionTemplate>>;
   V8FunctionTemplateMap& SelectInterfaceTemplateMap(const DOMWrapperWorld&);
   V8FunctionTemplateMap& SelectOperationTemplateMap(const DOMWrapperWorld&);
   bool HasInstance(const WrapperTypeInfo* untrusted,
@@ -238,12 +260,14 @@ class PLATFORM_EXPORT V8PerIsolateData {
                                                      v8::Local<v8::Value>,
                                                      V8FunctionTemplateMap&);
 
+  V8ContextSnapshotMode v8_context_snapshot_mode_;
   gin::IsolateHolder isolate_holder_;

[haraken, 2017/07/10 06:52:09]

// This isolate_holder_ must be initialized before initializing other members
below.

[peria, 2017/07/10 10:18:44]

Done.

 
-  // m_interfaceTemplateMapFor{,Non}MainWorld holds function templates for
+  // interface_template_map_for_{,non_}main_world holds function templates for
   // the inerface objects.
   V8FunctionTemplateMap interface_template_map_for_main_world_;
   V8FunctionTemplateMap interface_template_map_for_non_main_world_;
+
   // m_operationTemplateMapFor{,Non}MainWorld holds function templates for
   // the cross-origin accessible DOM operations.
   V8FunctionTemplateMap operation_template_map_for_main_world_;
@@ -252,6 +276,16 @@ class PLATFORM_EXPORT V8PerIsolateData {
   // Contains lists of eternal names, such as dictionary keys.
   HashMap<const void*, Vector<v8::Eternal<v8::Name>>> eternal_name_cache_;
 
+  // Members required for the V8 context snapshot.
+  // v8::Context is created from this blob data image. This needs to be
+  // instantiated before |isolate_holder_| gets instantiated.
+  v8::StartupData startup_data_;
+  // When taking a V8 context snapshot, we can't keep V8 objects with eternal
+  // handles. So we use a special interface map that doesn't use eternal handles
+  // instead of the default V8FunctionTemplateMap.
+  V8GlobalValueMap<const WrapperTypeInfo*, v8::FunctionTemplate, v8::kNotWeak>
+      interface_template_map_for_v8_context_snapshot_;
+
   std::unique_ptr<StringCache> string_cache_;
   std::unique_ptr<V8PrivateProperty> private_property_;
   RefPtr<ScriptState> script_regexp_script_state_;