GCanvas/core/android/memory/AutoPtr.h

/**
 * Created by G-Canvas Open Source Team.
 * Copyright (c) 2017, Alibaba, Inc. All rights reserved.
 *
 * This source code is licensed under the Apache Licence 2.0.
 * For the full copyright and license information, please view
 * the LICENSE file in the root directory of this source tree.
 */
#ifndef AUTOPTR_H_
#define AUTOPTR_H_

#include "IDelete.h"
#include "RefCount.h"

namespace gcanvas
{
template < typename T > class AutoPtr final
{
public:
    AutoPtr(T *r = nullptr) : mPtr(nullptr) { InternalAdd(r); }

    AutoPtr(const AutoPtr< T > &r) : mPtr(nullptr) { InternalAdd(r.RawData()); }

    ~AutoPtr() { InternalRelease(mPtr); }

    AutoPtr< T > &operator=(const AutoPtr< T > &r)
    {
        InternalAdd(r.RawData());
        return *this;
    }

    AutoPtr< T > &operator=(T *r)
    {
        InternalAdd(r);
        return *this;
    }

    T *operator->() { return RawData(); }

    T &operator*() { return *RawData(); }

    T *RawData() { return mPtr; }

    bool IsNULL() { return (mPtr == nullptr); }

private:
    void InternalAdd(RefCount *r)
    {
        if (r == nullptr) return;

        r->AddRef();

        if (mPtr) static_cast< RefCount * >(mPtr)->ReleaseRef();

        mPtr = (T *)r;
    }

    void InternalAdd(IDelete *r)
    {
        if (r == mPtr) return;

        if (mPtr) static_cast< IDelete * >(mPtr)->Delete();

        mPtr = (T *)r;
    }

    void InternalAdd(void *r)
    {
        if (r == mPtr) return;

        delete mPtr;

        mPtr = (T *)r;
    }

    void InternalRelease(RefCount *r)
    {
        static_cast< RefCount * >(mPtr)->ReleaseRef();
        mPtr = nullptr;
    }

    void InternalRelease(IDelete *r)
    {
        static_cast< IDelete * >(mPtr)->Delete();
        mPtr = nullptr;
    }

    void InternalRelease(void *r)
    {
        delete mPtr;
        mPtr = nullptr;
    }

private:
    T *mPtr;
};
}

#endif