/*
 *  Copyright 2018 NVIDIA Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

#pragma once

#include <thrust/detail/config.h>

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header
#include <thrust/detail/type_traits/pointer_traits.h>

#include <thrust/mr/memory_resource.h>
#include <thrust/mr/validator.h>

THRUST_NAMESPACE_BEGIN
namespace mr
{

template<typename Upstream, typename Pointer>
class fancy_pointer_resource final : public memory_resource<Pointer>, private validator<Upstream>
{
public:
    fancy_pointer_resource() : m_upstream(get_global_resource<Upstream>())
    {
    }

    fancy_pointer_resource(Upstream * upstream) : m_upstream(upstream)
    {
    }

    THRUST_NODISCARD
    virtual Pointer do_allocate(std::size_t bytes, std::size_t alignment = THRUST_MR_DEFAULT_ALIGNMENT) override
    {
        return static_cast<Pointer>(m_upstream->do_allocate(bytes, alignment));
    }

    virtual void do_deallocate(Pointer p, std::size_t bytes, std::size_t alignment) override
    {
        return m_upstream->do_deallocate(
            static_cast<typename Upstream::pointer>(
                thrust::detail::pointer_traits<Pointer>::get(p)),
            bytes, alignment);
    }

private:
    Upstream * m_upstream;
};

} // end mr
THRUST_NAMESPACE_END