src/support/allocators/zeroafterfree.h

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2015 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #ifndef BITCOIN_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H
   7 #define BITCOIN_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H
   8
   9 #include "support/cleanse.h"
  10
  11 #include <memory>
  12 #include <vector>
  13
  14 template <typename T>
  15 struct zero_after_free_allocator : public std::allocator<T> {
  16     // MSVC8 default copy constructor is broken
  17     typedef std::allocator<T> base;
  18     typedef typename base::size_type size_type;
  19     typedef typename base::difference_type difference_type;
  20     typedef typename base::pointer pointer;
  21     typedef typename base::const_pointer const_pointer;
  22     typedef typename base::reference reference;
  23     typedef typename base::const_reference const_reference;
  24     typedef typename base::value_type value_type;
  25     zero_after_free_allocator() noexcept {}
  26     zero_after_free_allocator(const zero_after_free_allocator& a) noexcept : base(a) {}
  27     template <typename U>
  28     zero_after_free_allocator(const zero_after_free_allocator<U>& a) noexcept : base(a)
  29     {
  30     }
  31     ~zero_after_free_allocator() noexcept {}
  32     template <typename _Other>
  33     struct rebind {
  34         typedef zero_after_free_allocator<_Other> other;
  35     };
  36
  37     void deallocate(T* p, std::size_t n)
  38     {
  39         if (p != nullptr)
  40             memory_cleanse(p, sizeof(T) * n);
  41         std::allocator<T>::deallocate(p, n);
  42     }
  43 };
  44
  45 // Byte-vector that clears its contents before deletion.
  46 typedef std::vector<char, zero_after_free_allocator<char> > CSerializeData;
  47
  48 #endif // BITCOIN_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H