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allocator.h
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1// Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors
2// Distributed under MIT license, or public domain if desired and
3// recognized in your jurisdiction.
4// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
5
6#ifndef JSON_ALLOCATOR_H_INCLUDED
7#define JSON_ALLOCATOR_H_INCLUDED
8
9#include <algorithm>
10#include <cstring>
11#include <memory>
12
13#pragma pack(push)
14#pragma pack()
15
16 namespace Json {
17 template <typename T> class SecureAllocator {
18 public:
19 // Type definitions
20 using value_type = T;
21 using pointer = T*;
22 using const_pointer = const T*;
23 using reference = T&;
24 using const_reference = const T&;
25 using size_type = std::size_t;
26 using difference_type = std::ptrdiff_t;
27
31 pointer allocate(size_type n) {
32 // allocate using "global operator new"
33 return static_cast<pointer>(::operator new(n * sizeof(T)));
34 }
35
41 void deallocate(pointer p, size_type n) {
42 // These constructs will not be removed by the compiler during optimization,
43 // unlike memset.
44#if defined(HAVE_MEMSET_S)
45 memset_s(p, n * sizeof(T), 0, n * sizeof(T));
46#elif defined(_WIN32)
47 RtlSecureZeroMemory(p, n * sizeof(T));
48#else
49 std::fill_n(reinterpret_cast<volatile unsigned char*>(p), n, 0);
50#endif
51
52 // free using "global operator delete"
53 ::operator delete(p);
54 }
55
59 template <typename... Args> void construct(pointer p, Args&&... args) {
60 // construct using "placement new" and "perfect forwarding"
61 ::new (static_cast<void*>(p)) T(std::forward<Args>(args)...);
62 }
63
64 size_type max_size() const { return size_t(-1) / sizeof(T); }
65
66 pointer address(reference x) const { return std::addressof(x); }
67
68 const_pointer address(const_reference x) const { return std::addressof(x); }
69
73 void destroy(pointer p) {
74 // destroy using "explicit destructor"
75 p->~T();
76 }
77
78 // Boilerplate
79 SecureAllocator() {}
80 template <typename U> SecureAllocator(const SecureAllocator<U>&) {}
81 template <typename U> struct rebind {
82 using other = SecureAllocator<U>;
83 };
84};
85
86 template <typename T, typename U>
87 bool operator==(const SecureAllocator<T>&, const SecureAllocator<U>&) {
88 return true;
89}
90
91 template <typename T, typename U>
92 bool operator!=(const SecureAllocator<T>&, const SecureAllocator<U>&) {
93 return false;
94}
95
96} // namespace Json
97
98#pragma pack(pop)
99
100#endif // JSON_ALLOCATOR_H_INCLUDED
Json::SecureAllocator
Definition allocator.h:17
Json::SecureAllocator::max_size
size_type max_size() const
Definition allocator.h:64
Json::SecureAllocator::address
const_pointer address(const_reference x) const
Definition allocator.h:68
Json::SecureAllocator::address
pointer address(reference x) const
Definition allocator.h:66
Json::SecureAllocator::const_reference
const T & const_reference
Definition allocator.h:24
Json::SecureAllocator::difference_type
std::ptrdiff_t difference_type
Definition allocator.h:26
Json::SecureAllocator::pointer
T * pointer
Definition allocator.h:21
Json::SecureAllocator::const_pointer
const T * const_pointer
Definition allocator.h:22
Json::SecureAllocator::reference
T & reference
Definition allocator.h:23
Json::SecureAllocator::size_type
std::size_t size_type
Definition allocator.h:25
Json::SecureAllocator::destroy
void destroy(pointer p)
Destroy an item in-place at pointer P.
Definition allocator.h:73
Json::SecureAllocator::deallocate
void deallocate(pointer p, size_type n)
Release memory which was allocated for N items at pointer P.
Definition allocator.h:41
Json::SecureAllocator::allocate
pointer allocate(size_type n)
Allocate memory for N items using the standard allocator.
Definition allocator.h:31
Json::SecureAllocator::SecureAllocator
SecureAllocator()
Definition allocator.h:79
Json::SecureAllocator::construct
void construct(pointer p, Args &&... args)
Construct an item in-place at pointer P.
Definition allocator.h:59
Json::SecureAllocator::value_type
T value_type
Definition allocator.h:20
Json::SecureAllocator::SecureAllocator
SecureAllocator(const SecureAllocator< U > &)
Definition allocator.h:80
Json
JSON (JavaScript Object Notation).
Definition allocator.h:16
Json::operator==
bool operator==(const SecureAllocator< T > &, const SecureAllocator< U > &)
Definition allocator.h:87
Json::operator!=
bool operator!=(const SecureAllocator< T > &, const SecureAllocator< U > &)
Definition allocator.h:92
Json::SecureAllocator::rebind
Definition allocator.h:81
Json::SecureAllocator::rebind::other
SecureAllocator< U > other
Definition allocator.h:82