| // 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_WRAPPER_PRIVATE_H_ |
| #define COBALT_SCRIPT_MOZJS_WRAPPER_PRIVATE_H_ |
| |
| #include <vector> |
| |
| #include "base/memory/ref_counted.h" |
| #include "base/memory/scoped_vector.h" |
| #include "base/memory/weak_ptr.h" |
| #include "cobalt/base/polymorphic_downcast.h" |
| #include "cobalt/script/mozjs/wrapper_factory.h" |
| #include "cobalt/script/wrappable.h" |
| #include "third_party/mozjs/js/src/jsapi.h" |
| |
| namespace cobalt { |
| namespace script { |
| namespace mozjs { |
| |
| // Our mozjs specific implementation of |script::Tracer|. Tracing sessions |
| // will be initiated from a |Wrapper| of SpiderMonkey's choice, and then it |
| // will be the |mozjs::Tracer|'s job to assist SpiderMonkey's garbage |
| // collector in traversing the graph of |Wrapper|s and |Wrappable|s. |
| // |Wrappable|s will inform us about what they can reach through their |
| // |TraceMembers| implementation, and then we will pass the reachable |
| // |Wrappable|'s |Wrapper| to SpiderMonkey GC if it exists, and otherwise |
| // continue traversing ourselves from |Wrappable| to (the unwrapped) |
| // |Wrappable|. |
| class Tracer : public ::cobalt::script::Tracer { |
| public: |
| explicit Tracer(JSTracer* js_tracer) : js_tracer_(js_tracer) {} |
| void Trace(Wrappable* wrappable) OVERRIDE; |
| |
| void TraceFrom(Wrappable* wrappable); |
| |
| private: |
| JSTracer* js_tracer_; |
| // Pending |Wrappable|s that we must traverse ourselves, since they did not |
| // have a |Wrapper|. |
| std::vector<Wrappable*> frontier_; |
| }; |
| |
| // Contains private data associated with a JSObject representing a JS wrapper |
| // for a Cobalt platform object. There should be a one-to-one mapping of such |
| // JSObjects and WrapperPrivate instances, and the corresponding WrapperPrivate |
| // must be destroyed when its JSObject is garbage collected. |
| class WrapperPrivate : public base::SupportsWeakPtr<WrapperPrivate> { |
| public: |
| typedef std::vector<Wrappable*> WrappableVector; |
| |
| template <typename T> |
| scoped_refptr<T> wrappable() const { |
| return base::polymorphic_downcast<T*>(wrappable_.get()); |
| } |
| |
| JSObject* js_object_proxy() const { return wrapper_proxy_; } |
| |
| // Create a new WrapperPrivate instance and associate it with the wrapper. |
| static void AddPrivateData(JSContext* context, JS::HandleObject wrapper_proxy, |
| const scoped_refptr<Wrappable>& wrappable); |
| |
| // Return true if the object has wrapper private. |
| static bool HasWrapperPrivate(JSContext* context, JS::HandleObject object); |
| |
| // Get the WrapperPrivate associated with the given Wrappable. A new JSObject |
| // and WrapperPrivate object may be created. |
| static WrapperPrivate* GetFromWrappable( |
| const scoped_refptr<Wrappable>& wrappable, JSContext* context, |
| WrapperFactory* wrapper_factory); |
| |
| // Get the |WrapperPrivate| instance associated with this |Wrapper| object. |
| // Will return |NULL| if |object| does not have a |Wrappable|, which also |
| // implies that it is not a |Wrapper|. |
| static WrapperPrivate* GetFromWrapperObject(JS::HandleObject object); |
| |
| // Get the WrapperPrivate instance associated with the target of this proxy. |
| static WrapperPrivate* GetFromProxyObject(JSContext* context, |
| JS::HandleObject proxy_object); |
| |
| // Get the |WrapperPrivate| instance associated with the object, which may |
| // be a proxy or a proxy target. Will return |NULL| if the |JSObject| that |
| // results from traversing |object|'s proxy chain does not have a |
| // |Wrappable|, which also implies that it is not a |Wrapper|. |
| static WrapperPrivate* GetFromObject(JSContext* context, |
| JS::HandleObject object); |
| |
| // Called when the wrapper object is about to be deleted by the GC. |
| static void Finalizer(JSFreeOp* /* free_op */, JSObject* object); |
| |
| // Trace callback called during garbage collection. |
| static void Trace(JSTracer* trace, JSObject* object); |
| |
| private: |
| WrapperPrivate(JSContext* context, const scoped_refptr<Wrappable>& wrappable, |
| JS::HandleObject wrapper_proxy); |
| ~WrapperPrivate(); |
| |
| JSContext* context_; |
| scoped_refptr<Wrappable> wrappable_; |
| JS::Heap<JSObject*> wrapper_proxy_; |
| |
| friend Tracer; |
| }; |
| |
| } // namespace mozjs |
| } // namespace script |
| } // namespace cobalt |
| |
| #endif // COBALT_SCRIPT_MOZJS_WRAPPER_PRIVATE_H_ |