dynamic_aligning_allocator.hpp

/* Copyright 2009-2017 Francesco Biscani (bluescarni@gmail.com)

This file is part of the Piranha library.

The Piranha library is free software; you can redistribute it and/or modify
it under the terms of either:

  * the GNU Lesser General Public License as published by the Free
    Software Foundation; either version 3 of the License, or (at your
    option) any later version.

or

  * the GNU General Public License as published by the Free Software
    Foundation; either version 3 of the License, or (at your option) any
    later version.

or both in parallel, as here.

The Piranha library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received copies of the GNU General Public License and the
GNU Lesser General Public License along with the Piranha library.  If not,
see https://www.gnu.org/licenses/. */

#ifndef PIRANHA_DYNAMIC_ALIGNING_ALLOCATOR_HPP
#define PIRANHA_DYNAMIC_ALIGNING_ALLOCATOR_HPP

#include <cstddef>
#include <limits>
#include <new>
#include <type_traits>

#include <piranha/config.hpp>
#include <piranha/memory.hpp>

namespace piranha
{


template <typename T>
class dynamic_aligning_allocator
{
public:

    using value_type = T;
    using size_type = std::size_t;

    using propagate_on_container_move_assignment = std::true_type;

    dynamic_aligning_allocator() : m_alignment(0)
    {
    }
    dynamic_aligning_allocator(const dynamic_aligning_allocator &) = default;
    dynamic_aligning_allocator(dynamic_aligning_allocator &&) = default;

    explicit dynamic_aligning_allocator(const std::size_t &alignment) : m_alignment(alignment)
    {
    }

    template <typename U>
    explicit dynamic_aligning_allocator(const dynamic_aligning_allocator<U> &other) : m_alignment(other.alignment())
    {
    }

    template <typename U>
    explicit dynamic_aligning_allocator(dynamic_aligning_allocator<U> &&other) : m_alignment(other.alignment())
    {
    }
    ~dynamic_aligning_allocator() = default;

    dynamic_aligning_allocator &operator=(const dynamic_aligning_allocator &other) = default;

    dynamic_aligning_allocator &operator=(dynamic_aligning_allocator &&other) = default;

    constexpr size_type max_size() const
    {
        return std::numeric_limits<size_type>::max() / sizeof(value_type);
    }

    value_type *allocate(const size_type &size) const
    {
        if (unlikely(size > max_size())) {
            piranha_throw(std::bad_alloc, );
        }
        return static_cast<value_type *>(
            aligned_palloc(m_alignment, static_cast<size_type>(size * sizeof(value_type))));
    }

    void deallocate(value_type *ptr, const size_type &) const
    {
        aligned_pfree(m_alignment, ptr);
    }

    bool operator==(const dynamic_aligning_allocator &other) const
    {
        return m_alignment == other.m_alignment;
    }

    bool operator!=(const dynamic_aligning_allocator &other) const
    {
        return !(this->operator==(other));
    }

    std::size_t alignment() const
    {
        return m_alignment;
    }

private:
    std::size_t m_alignment;
};
}

#endif