bindings/v8/DOMWrapperMap.h

/*
 * Copyright (C) 2012 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef DOMWrapperMap_h
#define DOMWrapperMap_h

#include "bindings/v8/WrapperTypeInfo.h"
#include <v8-util.h>
#include <v8.h>
#include "wtf/HashMap.h"

namespace WebCore {

template<class KeyType>
class DOMWrapperMap {
public:
    explicit DOMWrapperMap(v8::Isolate* isolate)
        : m_isolate(isolate)
        , m_map(isolate)
    {
    }

    v8::Handle<v8::Object> newLocal(KeyType* key, v8::Isolate* isolate)
    {
        return m_map.Get(key);
    }

    bool setReturnValueFrom(v8::ReturnValue<v8::Value> returnValue, KeyType* key)
    {
        return m_map.SetReturnValue(key, returnValue);
    }

    void setReference(const v8::Persistent<v8::Object>& parent, KeyType* key, v8::Isolate* isolate)
    {
        m_map.SetReference(key, parent);
    }

    bool containsKey(KeyType* key)
    {
        return m_map.Contains(key);
    }

    void set(KeyType* key, v8::Handle<v8::Object> wrapper, const WrapperConfiguration& configuration)
    {
        ASSERT(static_cast<KeyType*>(toNative(wrapper)) == key);
        RELEASE_ASSERT(!containsKey(key)); // See crbug.com/368095
        v8::UniquePersistent<v8::Object> unique(m_isolate, wrapper);
        configuration.configureWrapper(&unique);
        m_map.Set(key, unique.Pass());
    }

    void clear()
    {
        m_map.Clear();
    }

    void removeAndDispose(KeyType* key)
    {
        ASSERT(containsKey(key));
        m_map.Remove(key);
    }

private:
    class PersistentValueMapTraits {
    public:
        // Map traits:
        typedef HashMap<KeyType*, v8::PersistentContainerValue> Impl;
        typedef typename Impl::iterator Iterator;
        static size_t Size(const Impl* impl) { return impl->size(); }
        static bool Empty(Impl* impl) { return impl->isEmpty(); }
        static void Swap(Impl& impl, Impl& other) { impl.swap(other); }
        static Iterator Begin(Impl* impl) { return impl->begin(); }
        static Iterator End(Impl* impl) { return impl->end(); }
        static v8::PersistentContainerValue Value(Iterator& iter)
        {
            return iter->value;
        }
        static KeyType* Key(Iterator& iter) { return iter->key; }
        static v8::PersistentContainerValue Set(
            Impl* impl, KeyType* key, v8::PersistentContainerValue value)
        {
            v8::PersistentContainerValue oldValue = Get(impl, key);
            impl->set(key, value);
            return oldValue;
        }
        static v8::PersistentContainerValue Get(const Impl* impl, KeyType* key)
        {
            return impl->get(key);
        }

        static v8::PersistentContainerValue Remove(Impl* impl, KeyType* key)
        {
            return impl->take(key);
        }

        // Weak traits:
        static const v8::PersistentContainerCallbackType kCallbackType = v8::kWeak;
        typedef v8::PersistentValueMap<KeyType*, v8::Object, PersistentValueMapTraits> MapType;
        typedef MapType WeakCallbackDataType;

        static WeakCallbackDataType* WeakCallbackParameter(MapType* map, KeyType* key, v8::Local<v8::Object>& value)
        {
            return map;
        }

        static void DisposeCallbackData(WeakCallbackDataType* callbackData) { }

        static MapType* MapFromWeakCallbackData(
            const v8::WeakCallbackData<v8::Object, WeakCallbackDataType>& data)
        {
            return data.GetParameter();
        }

        static KeyType* KeyFromWeakCallbackData(
            const v8::WeakCallbackData<v8::Object, WeakCallbackDataType>& data)
        {
            return static_cast<KeyType*>(toNative(data.GetValue()));
        }

        // Dispose traits:
        // Generally nothing to do, but see below for a specialization for
        // DomWrapperMap<void>.
        static void Dispose(v8::Isolate* isolate, v8::UniquePersistent<v8::Object> value, KeyType* key) { }
    };

    v8::Isolate* m_isolate;
    typename PersistentValueMapTraits::MapType m_map;
};

template <>
inline void DOMWrapperMap<void>::PersistentValueMapTraits::Dispose(
    v8::Isolate* isolate,
    v8::UniquePersistent<v8::Object> value,
    void* key)
{
    RELEASE_ASSERT(!value.IsEmpty()); // See crbug.com/368095.
    releaseObject(v8::Local<v8::Object>::New(isolate, value));
}

} // namespace WebCore

#endif // DOMWrapperMap_h