| // Copyright 2016 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| #ifndef COBALT_SCRIPT_MOZJS_45_MOZJS_USER_OBJECT_HOLDER_H_ |
| #define COBALT_SCRIPT_MOZJS_45_MOZJS_USER_OBJECT_HOLDER_H_ |
| |
| #include "base/hash_tables.h" |
| #include "base/memory/weak_ptr.h" |
| #include "cobalt/base/polymorphic_downcast.h" |
| #include "cobalt/script/mozjs-45/mozjs_global_environment.h" |
| #include "cobalt/script/mozjs-45/referenced_object_map.h" |
| #include "cobalt/script/mozjs-45/util/algorithm_helpers.h" |
| #include "cobalt/script/mozjs-45/wrapper_factory.h" |
| #include "cobalt/script/mozjs-45/wrapper_private.h" |
| #include "cobalt/script/script_value.h" |
| #include "third_party/mozjs-45/js/src/jsapi.h" |
| |
| #include "nb/memory_scope.h" |
| |
| namespace cobalt { |
| namespace script { |
| namespace mozjs { |
| |
| // Template class that implements the ScriptValue template class for lifetime |
| // management of User Objects passed from the bindings layer into Cobalt. See |
| // the definition of ScriptValue for further detail. |
| // This class does not root the underlying JSObject that MozjsUserObjectType |
| // holds a reference to. The object will be traced when any owning objects are |
| // traced. |
| template <typename MozjsUserObjectType> |
| class MozjsUserObjectHolder |
| : public ScriptValue<typename MozjsUserObjectType::BaseType> { |
| public: |
| typedef ScriptValue<typename MozjsUserObjectType::BaseType> BaseClass; |
| |
| MozjsUserObjectHolder() : context_(NULL), wrapper_factory_(NULL) {} |
| |
| MozjsUserObjectHolder(JS::HandleObject object, JSContext* context, |
| WrapperFactory* wrapper_factory) |
| : handle_(MozjsUserObjectType(context, object)), |
| context_(context), |
| wrapper_factory_(wrapper_factory) {} |
| |
| MozjsUserObjectHolder(JS::HandleValue value, JSContext* context, |
| WrapperFactory* wrapper_factory) |
| : handle_(MozjsUserObjectType(context, value)), |
| context_(context), |
| wrapper_factory_(wrapper_factory) {} |
| |
| void RegisterOwner(Wrappable* owner) OVERRIDE { |
| JSAutoRequest auto_request(context_); |
| JS::RootedValue owned_value(context_, js_value()); |
| DLOG_IF(WARNING, handle_->WasCollected()) |
| << "Owned value has been garbage collected."; |
| // We have to check for null, because null is apparently a GC Thing. |
| if (!owned_value.isNullOrUndefined() && owned_value.isGCThing()) { |
| MozjsGlobalEnvironment* global_environment = |
| MozjsGlobalEnvironment::GetFromContext(context_); |
| intptr_t key = ReferencedObjectMap::GetKeyForWrappable(owner); |
| global_environment->referenced_objects()->AddReferencedObject( |
| key, owned_value); |
| } |
| } |
| |
| void DeregisterOwner(Wrappable* owner) OVERRIDE { |
| // |owner| may be in the process of being destructed, so don't use it. |
| JSAutoRequest auto_request(context_); |
| JS::RootedValue owned_value(context_, js_value()); |
| // We have to check for null, because null is apparently a GC Thing. |
| if (!owned_value.isNullOrUndefined() && owned_value.isGCThing()) { |
| MozjsGlobalEnvironment* global_environment = |
| MozjsGlobalEnvironment::GetFromContext(context_); |
| intptr_t key = ReferencedObjectMap::GetKeyForWrappable(owner); |
| global_environment->referenced_objects()->RemoveReferencedObject( |
| key, owned_value); |
| } |
| } |
| |
| void PreventGarbageCollection() OVERRIDE { |
| if (prevent_garbage_collection_count_++ == 0 && handle_) { |
| JSAutoRequest auto_request(context_); |
| persistent_root_ = JS::PersistentRootedValue(context_, handle_->value()); |
| } |
| } |
| |
| void AllowGarbageCollection() { |
| if (prevent_garbage_collection_count_++ == 0 && handle_) { |
| JSAutoRequest auto_request(context_); |
| persistent_root_ = base::nullopt; |
| } |
| } |
| |
| const typename MozjsUserObjectType::BaseType* GetScriptValue() |
| const OVERRIDE { |
| return handle_ ? &handle_.value() : NULL; |
| } |
| |
| scoped_ptr<BaseClass> MakeCopy() const OVERRIDE { |
| TRACK_MEMORY_SCOPE("Javascript"); |
| DCHECK(handle_); |
| JSAutoRequest auto_request(context_); |
| JS::RootedValue rooted_value(context_, js_value()); |
| return make_scoped_ptr<BaseClass>( |
| new MozjsUserObjectHolder(rooted_value, context_, wrapper_factory_)); |
| } |
| |
| bool EqualTo(const BaseClass& other) const OVERRIDE { |
| const MozjsUserObjectHolder* mozjs_other = |
| base::polymorphic_downcast<const MozjsUserObjectHolder*>(&other); |
| if (!handle_) { |
| return !mozjs_other->handle_; |
| } else if (!mozjs_other->handle_) { |
| return false; |
| } |
| |
| DCHECK(handle_); |
| DCHECK(mozjs_other->handle_); |
| |
| JS::RootedValue value1(context_, js_value()); |
| JS::RootedValue value2(context_, mozjs_other->js_value()); |
| return util::IsSameGcThing(context_, value1, value2); |
| } |
| |
| const JS::Value& js_value() const { |
| DCHECK(handle_); |
| return handle_->value(); |
| } |
| |
| JSObject* js_object() const { |
| DCHECK(handle_); |
| return handle_->handle(); |
| } |
| |
| private: |
| typedef base::hash_map<const Wrappable*, base::WeakPtr<WrapperPrivate> > |
| WrappableAndPrivateHashMap; |
| |
| JSContext* context_; |
| base::optional<MozjsUserObjectType> handle_; |
| WrapperFactory* wrapper_factory_; |
| int prevent_garbage_collection_count_; |
| base::optional<JS::Value> persistent_root_; |
| }; |
| |
| } // namespace mozjs |
| } // namespace script |
| } // namespace cobalt |
| |
| #endif // COBALT_SCRIPT_MOZJS_45_MOZJS_USER_OBJECT_HOLDER_H_ |