forked from mirrors/gecko-dev
8ad76c7e47
Depends on D66008 Differential Revision: https://phabricator.services.mozilla.com/D66010 --HG-- extra : moz-landing-system : lando
89 lines
2.4 KiB
C++
89 lines
2.4 KiB
C++
// Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors
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// Distributed under MIT license, or public domain if desired and
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// recognized in your jurisdiction.
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// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
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#ifndef CPPTL_JSON_ALLOCATOR_H_INCLUDED
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#define CPPTL_JSON_ALLOCATOR_H_INCLUDED
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#include <cstring>
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#include <memory>
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#pragma pack(push, 8)
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namespace Json {
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template <typename T> class SecureAllocator {
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public:
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// Type definitions
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using value_type = T;
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using pointer = T*;
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using const_pointer = const T*;
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using reference = T&;
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using const_reference = const T&;
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using size_type = std::size_t;
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using difference_type = std::ptrdiff_t;
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/**
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* Allocate memory for N items using the standard allocator.
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*/
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pointer allocate(size_type n) {
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// allocate using "global operator new"
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return static_cast<pointer>(::operator new(n * sizeof(T)));
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}
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/**
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* Release memory which was allocated for N items at pointer P.
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*
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* The memory block is filled with zeroes before being released.
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* The pointer argument is tagged as "volatile" to prevent the
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* compiler optimizing out this critical step.
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*/
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void deallocate(volatile pointer p, size_type n) {
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std::memset(p, 0, n * sizeof(T));
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// free using "global operator delete"
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::operator delete(p);
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}
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/**
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* Construct an item in-place at pointer P.
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*/
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template <typename... Args> void construct(pointer p, Args&&... args) {
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// construct using "placement new" and "perfect forwarding"
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::new (static_cast<void*>(p)) T(std::forward<Args>(args)...);
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}
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size_type max_size() const { return size_t(-1) / sizeof(T); }
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pointer address(reference x) const { return std::addressof(x); }
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const_pointer address(const_reference x) const { return std::addressof(x); }
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/**
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* Destroy an item in-place at pointer P.
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*/
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void destroy(pointer p) {
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// destroy using "explicit destructor"
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p->~T();
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}
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// Boilerplate
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SecureAllocator() = default;
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template <typename U> SecureAllocator(const SecureAllocator<U>&) {}
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template <typename U> struct rebind { using other = SecureAllocator<U>; };
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};
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template <typename T, typename U>
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bool operator==(const SecureAllocator<T>&, const SecureAllocator<U>&) {
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return true;
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}
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template <typename T, typename U>
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bool operator!=(const SecureAllocator<T>&, const SecureAllocator<U>&) {
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return false;
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}
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} // namespace Json
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#pragma pack(pop)
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#endif // CPPTL_JSON_ALLOCATOR_H_INCLUDED
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