// SPDX-License-Identifier: BSD-2-Clause
/* Copyright (C) 2014 - 2020 Intel Corporation. */

#pragma once

#include <hbwmalloc.h>

#include <stddef.h>
#include <new>
/*
 * Header file for the C++ allocator compatible with the C++ standard library allocator concepts.
 * More details in hbwallocator(3) man page.
 * Note: memory heap management is based on hbwmalloc, refer to the hbwmalloc man page for more information.
 *
 * Functionality defined in this header is considered as EXPERIMENTAL API.
 * API standards are described in memkind(3) man page.
 */
namespace hbw
{

    template <class T>
    class allocator
    {
    public:
        /*
         *  Public member types required and defined by the standard library allocator concepts.
         */
        typedef size_t size_type;
        typedef ptrdiff_t difference_type;
        typedef T *pointer;
        typedef const T *const_pointer;
        typedef T &reference;
        typedef const T &const_reference;
        typedef T value_type;

        template <class U>
        struct rebind {
            typedef hbw::allocator<U> other;
        };

        /*
         *  Public member functions required and defined by the standard library allocator concepts.
         */
        allocator() throw() { }

        template <class U>
        allocator(const allocator<U> &) throw() { }

        ~allocator() throw() { }

        pointer address(reference x) const
        {
            return &x;
        }

        const_pointer address(const_reference x) const
        {
            return &x;
        }

        /*
         *  Allocates n*sizeof(T) bytes of high bandwidth memory using hbw_malloc().
         *  Throws std::bad_alloc when cannot allocate memory.
         */
        pointer allocate(size_type n, const void * = 0)
        {
            if (n > this->max_size()) {
                throw std::bad_alloc();
            }
            pointer result = static_cast<pointer>(hbw_malloc(n * sizeof(T)));
            if (!result) {
                throw std::bad_alloc();
            }
            return result;
        }

        /*
         *  Deallocates memory associated with pointer returned by allocate() using hbw_free().
         */
        void deallocate(pointer p, size_type n)
        {
            hbw_free(static_cast<void *>(p));
        }

        size_type max_size() const throw()
        {
            return size_t(-1) / sizeof(T);
        }

        void construct(pointer p, const_reference val)
        {
            ::new(p) value_type(val);
        }

        void destroy(pointer p)
        {
            p->~T();
        }
    };

    template <class T, class U>
    bool operator==(const allocator<T> &, const allocator<U> &)
    {
        return true;
    }

    template <class T, class U>
    bool operator!=(const allocator<T> &, const allocator<U> &)
    {
        return false;
    }

}
