Source/WebCore/dom/MemoryInstrumentation.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 MemoryInstrumentation_h
#define MemoryInstrumentation_h

#include <wtf/Forward.h>
#include <wtf/OwnPtr.h>
#include <wtf/RefPtr.h>

namespace WebCore {

class MemoryObjectInfo;

class MemoryInstrumentation {
public:
    virtual ~MemoryInstrumentation() { }

    enum ObjectType {
        Other,
        DOM,
        CSS,
        LastTypeEntry
    };

    template <typename T> void reportInstrumentedObject(const T&);
    template <typename T> void reportObject(const T&) { }
    template <typename T> void reportInstrumentedPointer(const T*);
    template <typename T> void reportPointer(const T* object, ObjectType objectType)
    {
        if (!object || visited(object))
            return;
        countObjectSize(objectType, sizeof(T));
    }

private:
    friend class MemoryObjectInfo;

    virtual void reportString(ObjectType, const String&) = 0;
    virtual void countObjectSize(ObjectType, size_t) = 0;
    virtual bool visited(const void*) = 0;
};

class MemoryObjectInfo {
public:
    MemoryObjectInfo(MemoryInstrumentation* memoryInstrumentation)
        : m_memoryInstrumentation(memoryInstrumentation)
        , m_objectType(MemoryInstrumentation::Other)
        , m_objectSize(0)
     { }

    template <typename P>
    void reportInstrumentedPointer(const P* memberPointer)
    {
        m_memoryInstrumentation->reportInstrumentedPointer(memberPointer);
    }

    template <typename P>
    void reportPointer(const P* pointer, MemoryInstrumentation::ObjectType objectType)
    {
        m_memoryInstrumentation->reportPointer(pointer, objectType);
    }

    template <typename T>
    void reportInstrumentedObject(const T& memberObject)
    {
        m_memoryInstrumentation->reportInstrumentedObject(memberObject);
    }

    template <typename T>
    void reportObject(const T& object) { m_memoryInstrumentation->reportObject(object); }

    template <typename T>
    void reportObjectInfo(const T*, MemoryInstrumentation::ObjectType objectType)
    {
        if (m_objectType != MemoryInstrumentation::Other)
            return;
        m_objectType = objectType;
        m_objectSize = sizeof(T);
    }

    void reportString(const String& string)
    {
        m_memoryInstrumentation->reportString(objectType(), string);
    }

    MemoryInstrumentation::ObjectType objectType() const { return m_objectType; }
    size_t objectSize() const { return m_objectSize; }

 private:
    MemoryInstrumentation* m_memoryInstrumentation;
    MemoryInstrumentation::ObjectType m_objectType;
    size_t m_objectSize;
};

template <typename T>
void MemoryInstrumentation::reportInstrumentedPointer(const T* const object)
{
    if (!object || visited(object))
        return;
    MemoryObjectInfo memoryObjectInfo(this);
    object->reportMemoryUsage(&memoryObjectInfo);
    countObjectSize(memoryObjectInfo.objectType(), memoryObjectInfo.objectSize());
}

template<typename T>
void MemoryInstrumentation::reportInstrumentedObject(const T& object)
{
    if (visited(&object))
        return;
    MemoryObjectInfo memoryObjectInfo(this);
    object.reportMemoryUsage(&memoryObjectInfo);
}

} // namespace WebCore

#endif // !defined(MemoryInstrumentation_h)