1/*
2 * Copyright (C) 2009 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef DOMData_h
32#define DOMData_h
33
34#include "DOMDataStore.h"
35#include "V8DOMWrapper.h"
36
37namespace WebCore {
38
39    // DOMData
40    //
41    // DOMData represents the all the DOM wrappers for a given thread.  In
42    // particular, DOMData holds wrappers for all the isolated worlds in the
43    // thread.  The DOMData for the main thread and the DOMData for child threads
44    // use different subclasses.
45    //
46    class DOMData {
47        WTF_MAKE_NONCOPYABLE(DOMData);
48    public:
49        DOMData();
50        virtual ~DOMData();
51
52        static DOMData* getCurrent();
53        virtual DOMDataStore& getStore() = 0;
54
55        template<typename T>
56        static void handleWeakObject(DOMDataStore::DOMWrapperMapType, v8::Persistent<v8::Object>, T* domObject);
57
58        template<typename T>
59        static void removeObjectsFromWrapperMap(DOMDataStore* store, AbstractWeakReferenceMap<T, v8::Object>& domMap);
60
61        ThreadIdentifier owningThread() const { return m_owningThread; }
62
63    private:
64        static void derefObject(WrapperTypeInfo* type, void* domObject);
65
66        template<typename T>
67        class WrapperMapObjectRemover : public WeakReferenceMap<T, v8::Object>::Visitor {
68        public:
69            virtual void visitDOMWrapper(DOMDataStore* store, T* domObject, v8::Persistent<v8::Object> v8Object)
70            {
71                WrapperTypeInfo* type = V8DOMWrapper::domWrapperType(v8Object);
72                derefObject(type, domObject);
73                v8Object.Dispose();
74            }
75        };
76
77        ThreadIdentifier m_owningThread;
78    };
79
80    template<typename T>
81    void DOMData::handleWeakObject(DOMDataStore::DOMWrapperMapType mapType, v8::Persistent<v8::Object> v8Object, T* domObject)
82    {
83        WrapperTypeInfo* type = V8DOMWrapper::domWrapperType(v8Object);
84        DOMDataList& list = DOMDataStore::allStores();
85        bool found = false;
86        for (size_t i = 0; i < list.size(); ++i) {
87            DOMDataStore* store = list[i];
88            ASSERT(store->domData()->owningThread() == WTF::currentThread());
89
90            DOMWrapperMap<T>* domMap = static_cast<DOMWrapperMap<T>*>(store->getDOMWrapperMap(mapType));
91            if (domMap->removeIfPresent(domObject, v8Object)) {
92                derefObject(type, domObject);
93                found = true;
94            }
95        }
96
97        // If not found, it means map for the wrapper has been already destroyed, just dispose the
98        // handle and deref the object to fight memory leak.
99        if (!found) {
100            v8Object.Dispose();
101            derefObject(type, domObject);
102        }
103    }
104
105    template<typename T>
106    void DOMData::removeObjectsFromWrapperMap(DOMDataStore* store, AbstractWeakReferenceMap<T, v8::Object>& domMap)
107    {
108        WrapperMapObjectRemover<T> remover;
109        domMap.visit(store, &remover);
110        domMap.clear();
111    }
112
113} // namespace WebCore
114
115#endif // DOMData_h
116