Source/bindings/v8/DOMDataStore.h

/*
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 * in the documentation and/or other materials provided with the
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#ifndef DOMDataStore_h
#define DOMDataStore_h

#include "bindings/v8/DOMWrapperMap.h"
#include "bindings/v8/DOMWrapperWorld.h"
#include "bindings/v8/ScriptWrappable.h"
#include "bindings/v8/WrapperTypeInfo.h"
#include <v8.h>
#include "wtf/Noncopyable.h"
#include "wtf/StdLibExtras.h"

namespace WebCore {

class Node;

class DOMDataStore {
    WTF_MAKE_NONCOPYABLE(DOMDataStore);
public:
    explicit DOMDataStore(WrapperWorldType);
    ~DOMDataStore();

    static DOMDataStore& current(v8::Isolate*);

    template<typename V8T, typename T, typename Wrappable>
    static bool setReturnValueFromWrapperFast(v8::ReturnValue<v8::Value> returnValue, T* object, v8::Local<v8::Object> holder, Wrappable* wrappable)
    {
        // What we'd really like to check here is whether we're in the
        // main world or in an isolated world. The fastest way to do that
        // is to check that there is no isolated world and the 'object'
        // is an object that can exist in the main world. The second fastest
        // way is to check whether the wrappable's wrapper is the same as
        // the holder.
        if ((!DOMWrapperWorld::isolatedWorldsExist() && !canExistInWorker(object)) || holderContainsWrapper(holder, wrappable)) {
            if (ScriptWrappable::wrapperCanBeStoredInObject(object))
                return ScriptWrappable::setReturnValueWithSecurityCheck<V8T>(returnValue, object);
            return mainWorldStore().m_wrapperMap.setReturnValueFrom(returnValue, V8T::toInternalPointer(object));
        }
        return current(returnValue.GetIsolate()).template setReturnValueFrom<V8T>(returnValue, object);
    }

    template<typename V8T, typename T>
    static bool setReturnValueFromWrapper(v8::ReturnValue<v8::Value> returnValue, T* object)
    {
        if (ScriptWrappable::wrapperCanBeStoredInObject(object) && !canExistInWorker(object)) {
            if (LIKELY(!DOMWrapperWorld::isolatedWorldsExist()))
                return ScriptWrappable::setReturnValueWithSecurityCheck<V8T>(returnValue, object);
        }
        return current(returnValue.GetIsolate()).template setReturnValueFrom<V8T>(returnValue, object);
    }

    template<typename V8T, typename T>
    static bool setReturnValueFromWrapperForMainWorld(v8::ReturnValue<v8::Value> returnValue, T* object)
    {
        if (ScriptWrappable::wrapperCanBeStoredInObject(object))
            return ScriptWrappable::setReturnValue(returnValue, object);
        return mainWorldStore().m_wrapperMap.setReturnValueFrom(returnValue, V8T::toInternalPointer(object));
    }

    template<typename V8T, typename T>
    static v8::Handle<v8::Object> getWrapper(T* object, v8::Isolate* isolate)
    {
        if (ScriptWrappable::wrapperCanBeStoredInObject(object) && !canExistInWorker(object)) {
            if (LIKELY(!DOMWrapperWorld::isolatedWorldsExist())) {
                v8::Handle<v8::Object> result = ScriptWrappable::getUnsafeWrapperFromObject(object).newLocal(isolate);
                // Security: always guard against malicious tampering.
                RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(result.IsEmpty() || result->GetAlignedPointerFromInternalField(v8DOMWrapperObjectIndex) == V8T::toInternalPointer(object));
                return result;
            }
        }
        return current(isolate).template get<V8T>(object, isolate);
    }

    template<typename V8T, typename T>
    static void setWrapperReference(const v8::Persistent<v8::Object>& parent, T* child, v8::Isolate* isolate)
    {
        if (ScriptWrappable::wrapperCanBeStoredInObject(child) && !canExistInWorker(child)) {
            if (LIKELY(!DOMWrapperWorld::isolatedWorldsExist())) {
                UnsafePersistent<v8::Object> unsafePersistent = ScriptWrappable::getUnsafeWrapperFromObject(child);
                // Security: always guard against malicious tampering.
                RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(unsafePersistent.isEmpty() || unsafePersistent.value()->GetAlignedPointerFromInternalField(v8DOMWrapperObjectIndex) == V8T::toInternalPointer(child));
                unsafePersistent.setReferenceFrom(parent, isolate);
            }
        }
        current(isolate).template setReference<V8T>(parent, child, isolate);
    }

    template<typename V8T, typename T>
    static void setWrapper(T* object, v8::Handle<v8::Object> wrapper, v8::Isolate* isolate, const WrapperConfiguration& configuration)
    {
        if (ScriptWrappable::wrapperCanBeStoredInObject(object) && !canExistInWorker(object)) {
            if (LIKELY(!DOMWrapperWorld::isolatedWorldsExist())) {
                ScriptWrappable::setWrapperInObject(object, wrapper, isolate, configuration);
                return;
            }
        }
        return current(isolate).template set<V8T>(object, wrapper, isolate, configuration);
    }

    template<typename V8T, typename T>
    static bool containsWrapper(T* object, v8::Isolate* isolate)
    {
        return current(isolate).template containsWrapper<V8T>(object);
    }

    template<typename V8T, typename T>
    inline v8::Handle<v8::Object> get(T* object, v8::Isolate* isolate)
    {
        if (ScriptWrappable::wrapperCanBeStoredInObject(object) && m_type == MainWorld)
            return ScriptWrappable::getUnsafeWrapperFromObject(object).newLocal(isolate);
        return m_wrapperMap.newLocal(V8T::toInternalPointer(object), isolate);
    }

    template<typename V8T, typename T>
    inline void setReference(const v8::Persistent<v8::Object>& parent, T* child, v8::Isolate* isolate)
    {
        if (ScriptWrappable::wrapperCanBeStoredInObject(child) && m_type == MainWorld) {
            ScriptWrappable::getUnsafeWrapperFromObject(child).setReferenceFrom(parent, isolate);
            return;
        }
        m_wrapperMap.setReference(parent, V8T::toInternalPointer(child), isolate);
    }

    template<typename V8T, typename T>
    inline bool setReturnValueFrom(v8::ReturnValue<v8::Value> returnValue, T* object)
    {
        if (ScriptWrappable::wrapperCanBeStoredInObject(object) && m_type == MainWorld)
            return ScriptWrappable::setReturnValue(returnValue, object);
        return m_wrapperMap.setReturnValueFrom(returnValue, V8T::toInternalPointer(object));
    }

    template<typename V8T, typename T>
    inline bool containsWrapper(T* object)
    {
        if (ScriptWrappable::wrapperCanBeStoredInObject(object) && m_type == MainWorld)
            return !ScriptWrappable::getUnsafeWrapperFromObject(object).isEmpty();
        return m_wrapperMap.containsKey(V8T::toInternalPointer(object));
    }

private:
    template<typename V8T, typename T>
    inline void set(T* object, v8::Handle<v8::Object> wrapper, v8::Isolate* isolate, const WrapperConfiguration& configuration)
    {
        ASSERT(!!object);
        ASSERT(!wrapper.IsEmpty());
        if (ScriptWrappable::wrapperCanBeStoredInObject(object) && m_type == MainWorld) {
            ScriptWrappable::setWrapperInObject(object, wrapper, isolate, configuration);
            return;
        }
        m_wrapperMap.set(V8T::toInternalPointer(object), wrapper, configuration);
    }

    static DOMDataStore& mainWorldStore();

    static bool canExistInWorker(void*) { return true; }
    static bool canExistInWorker(Node*) { return false; }

    static bool holderContainsWrapper(v8::Local<v8::Object>, void*)
    {
        return false;
    }

    static bool holderContainsWrapper(v8::Local<v8::Object> holder, ScriptWrappable* wrappable)
    {
        // Verify our assumptions about the main world.
        UnsafePersistent<v8::Object> unsafePersistent = wrappable->unsafePersistent();
        ASSERT(unsafePersistent.isEmpty() || !(holder == *unsafePersistent.persistent()) || current(v8::Isolate::GetCurrent()).m_type == MainWorld);
        return holder == *unsafePersistent.persistent();
    }

    WrapperWorldType m_type;
    DOMWrapperMap<void> m_wrapperMap;
};

} // namespace WebCore

#endif // DOMDataStore_h