thehub/libs/utils/support/allocators/zeroafterfree.h

/*
 * This file is part of the Flowee project
 * Copyright (C) 2009-2010 Satoshi Nakamoto
 * Copyright (C) 2009-2015 The Bitcoin Core developers
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of 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.
 *
 * This program 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 a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef FLOWEE_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H
#define FLOWEE_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H

#include "support/cleanse.h"

#include <memory>
#include <vector>

template <typename T>
struct zero_after_free_allocator : public std::allocator<T> {
    // MSVC8 default copy constructor is broken
    typedef std::allocator<T> base;
    typedef typename base::size_type size_type;
    typedef typename base::difference_type difference_type;
    typedef typename base::pointer pointer;
    typedef typename base::const_pointer const_pointer;
    typedef typename base::reference reference;
    typedef typename base::const_reference const_reference;
    typedef typename base::value_type value_type;
    zero_after_free_allocator() throw() {}
    zero_after_free_allocator(const zero_after_free_allocator& a) throw() : base(a) {}
    template <typename U>
    zero_after_free_allocator(const zero_after_free_allocator<U>& a) throw() : base(a)
    {
    }
    ~zero_after_free_allocator() throw() {}
    template <typename _Other>
    struct rebind {
        typedef zero_after_free_allocator<_Other> other;
    };

    void deallocate(T* p, std::size_t n)
    {
        if (p != NULL)
            memory_cleanse(p, sizeof(T) * n);
        std::allocator<T>::deallocate(p, n);
    }
};

// Byte-vector that clears its contents before deletion.
typedef std::vector<char, zero_after_free_allocator<char> > CSerializeData;

#endif