ext-boost/boost/smart_ptr/allocate_shared_array.hpp
2022-08-26 23:24:04 +03:00

353 lines
9.7 KiB
C++

/*
Copyright 2012-2019 Glen Joseph Fernandes
(glenjofe@gmail.com)
Distributed under the Boost Software License, Version 1.0.
(http://www.boost.org/LICENSE_1_0.txt)
*/
#ifndef BOOST_SMART_PTR_ALLOCATE_SHARED_ARRAY_HPP
#define BOOST_SMART_PTR_ALLOCATE_SHARED_ARRAY_HPP
#include <boost/core/allocator_access.hpp>
#include <boost/core/alloc_construct.hpp>
#include <boost/core/first_scalar.hpp>
#include <boost/smart_ptr/shared_ptr.hpp>
#include <boost/type_traits/alignment_of.hpp>
#include <boost/type_traits/enable_if.hpp>
#include <boost/type_traits/extent.hpp>
#include <boost/type_traits/is_bounded_array.hpp>
#include <boost/type_traits/is_unbounded_array.hpp>
#include <boost/type_traits/remove_cv.hpp>
#include <boost/type_traits/remove_extent.hpp>
#include <boost/type_traits/type_with_alignment.hpp>
namespace boost {
namespace detail {
template<class T>
struct sp_array_element {
typedef typename boost::remove_cv<typename
boost::remove_extent<T>::type>::type type;
};
template<class T>
struct sp_array_count {
enum {
value = 1
};
};
template<class T, std::size_t N>
struct sp_array_count<T[N]> {
enum {
value = N * sp_array_count<T>::value
};
};
template<std::size_t N, std::size_t M>
struct sp_max_size {
enum {
value = N < M ? M : N
};
};
template<std::size_t N, std::size_t M>
struct sp_align_up {
enum {
value = (N + M - 1) & ~(M - 1)
};
};
template<class T>
BOOST_CONSTEXPR inline std::size_t
sp_objects(std::size_t size) BOOST_SP_NOEXCEPT
{
return (size + sizeof(T) - 1) / sizeof(T);
}
template<class A>
class sp_array_state {
public:
typedef A type;
template<class U>
sp_array_state(const U& _allocator, std::size_t _size) BOOST_SP_NOEXCEPT
: allocator_(_allocator),
size_(_size) { }
A& allocator() BOOST_SP_NOEXCEPT {
return allocator_;
}
std::size_t size() const BOOST_SP_NOEXCEPT {
return size_;
}
private:
A allocator_;
std::size_t size_;
};
template<class A, std::size_t N>
class sp_size_array_state {
public:
typedef A type;
template<class U>
sp_size_array_state(const U& _allocator, std::size_t) BOOST_SP_NOEXCEPT
: allocator_(_allocator) { }
A& allocator() BOOST_SP_NOEXCEPT {
return allocator_;
}
BOOST_CONSTEXPR std::size_t size() const BOOST_SP_NOEXCEPT {
return N;
}
private:
A allocator_;
};
template<class T, class U>
struct sp_array_alignment {
enum {
value = sp_max_size<boost::alignment_of<T>::value,
boost::alignment_of<U>::value>::value
};
};
template<class T, class U>
struct sp_array_offset {
enum {
value = sp_align_up<sizeof(T), sp_array_alignment<T, U>::value>::value
};
};
template<class U, class T>
inline U*
sp_array_start(T* base) BOOST_SP_NOEXCEPT
{
enum {
size = sp_array_offset<T, U>::value
};
return reinterpret_cast<U*>(reinterpret_cast<char*>(base) + size);
}
template<class A, class T>
class sp_array_creator {
typedef typename A::value_type element;
enum {
offset = sp_array_offset<T, element>::value
};
typedef typename boost::type_with_alignment<sp_array_alignment<T,
element>::value>::type type;
public:
template<class U>
sp_array_creator(const U& other, std::size_t size) BOOST_SP_NOEXCEPT
: other_(other),
size_(sp_objects<type>(offset + sizeof(element) * size)) { }
T* create() {
return reinterpret_cast<T*>(other_.allocate(size_));
}
void destroy(T* base) {
other_.deallocate(reinterpret_cast<type*>(base), size_);
}
private:
typename boost::allocator_rebind<A, type>::type other_;
std::size_t size_;
};
template<class T>
class BOOST_SYMBOL_VISIBLE sp_array_base
: public sp_counted_base {
typedef typename T::type allocator;
public:
typedef typename allocator::value_type type;
template<class A>
sp_array_base(const A& other, type* start, std::size_t size)
: state_(other, size) {
boost::alloc_construct_n(state_.allocator(),
boost::first_scalar(start),
state_.size() * sp_array_count<type>::value);
}
template<class A, class U>
sp_array_base(const A& other, type* start, std::size_t size, const U& list)
: state_(other, size) {
enum {
count = sp_array_count<type>::value
};
boost::alloc_construct_n(state_.allocator(),
boost::first_scalar(start), state_.size() * count,
boost::first_scalar(&list), count);
}
T& state() BOOST_SP_NOEXCEPT {
return state_;
}
void dispose() BOOST_SP_NOEXCEPT BOOST_OVERRIDE {
boost::alloc_destroy_n(state_.allocator(),
boost::first_scalar(sp_array_start<type>(this)),
state_.size() * sp_array_count<type>::value);
}
void destroy() BOOST_SP_NOEXCEPT BOOST_OVERRIDE {
sp_array_creator<allocator, sp_array_base> other(state_.allocator(),
state_.size());
this->~sp_array_base();
other.destroy(this);
}
void* get_deleter(const sp_typeinfo_&) BOOST_SP_NOEXCEPT BOOST_OVERRIDE {
return 0;
}
void* get_local_deleter(const sp_typeinfo_&)
BOOST_SP_NOEXCEPT BOOST_OVERRIDE {
return 0;
}
void* get_untyped_deleter() BOOST_SP_NOEXCEPT BOOST_OVERRIDE {
return 0;
}
private:
T state_;
};
template<class A, class T>
struct sp_array_result {
public:
template<class U>
sp_array_result(const U& other, std::size_t size)
: creator_(other, size),
result_(creator_.create()) { }
~sp_array_result() {
if (result_) {
creator_.destroy(result_);
}
}
T* get() const BOOST_SP_NOEXCEPT {
return result_;
}
void release() BOOST_SP_NOEXCEPT {
result_ = 0;
}
private:
sp_array_result(const sp_array_result&);
sp_array_result& operator=(const sp_array_result&);
sp_array_creator<A, T> creator_;
T* result_;
};
} /* detail */
template<class T, class A>
inline typename enable_if_<is_unbounded_array<T>::value, shared_ptr<T> >::type
allocate_shared(const A& allocator, std::size_t count)
{
typedef typename detail::sp_array_element<T>::type element;
typedef typename allocator_rebind<A, element>::type other;
typedef detail::sp_array_state<other> state;
typedef detail::sp_array_base<state> base;
detail::sp_array_result<other, base> result(allocator, count);
base* node = result.get();
element* start = detail::sp_array_start<element>(node);
::new(static_cast<void*>(node)) base(allocator, start, count);
result.release();
return shared_ptr<T>(detail::sp_internal_constructor_tag(), start,
detail::shared_count(static_cast<detail::sp_counted_base*>(node)));
}
template<class T, class A>
inline typename enable_if_<is_bounded_array<T>::value, shared_ptr<T> >::type
allocate_shared(const A& allocator)
{
enum {
count = extent<T>::value
};
typedef typename detail::sp_array_element<T>::type element;
typedef typename allocator_rebind<A, element>::type other;
typedef detail::sp_size_array_state<other, extent<T>::value> state;
typedef detail::sp_array_base<state> base;
detail::sp_array_result<other, base> result(allocator, count);
base* node = result.get();
element* start = detail::sp_array_start<element>(node);
::new(static_cast<void*>(node)) base(allocator, start, count);
result.release();
return shared_ptr<T>(detail::sp_internal_constructor_tag(), start,
detail::shared_count(static_cast<detail::sp_counted_base*>(node)));
}
template<class T, class A>
inline typename enable_if_<is_unbounded_array<T>::value, shared_ptr<T> >::type
allocate_shared(const A& allocator, std::size_t count,
const typename remove_extent<T>::type& value)
{
typedef typename detail::sp_array_element<T>::type element;
typedef typename allocator_rebind<A, element>::type other;
typedef detail::sp_array_state<other> state;
typedef detail::sp_array_base<state> base;
detail::sp_array_result<other, base> result(allocator, count);
base* node = result.get();
element* start = detail::sp_array_start<element>(node);
::new(static_cast<void*>(node)) base(allocator, start, count, value);
result.release();
return shared_ptr<T>(detail::sp_internal_constructor_tag(), start,
detail::shared_count(static_cast<detail::sp_counted_base*>(node)));
}
template<class T, class A>
inline typename enable_if_<is_bounded_array<T>::value, shared_ptr<T> >::type
allocate_shared(const A& allocator,
const typename remove_extent<T>::type& value)
{
enum {
count = extent<T>::value
};
typedef typename detail::sp_array_element<T>::type element;
typedef typename allocator_rebind<A, element>::type other;
typedef detail::sp_size_array_state<other, extent<T>::value> state;
typedef detail::sp_array_base<state> base;
detail::sp_array_result<other, base> result(allocator, count);
base* node = result.get();
element* start = detail::sp_array_start<element>(node);
::new(static_cast<void*>(node)) base(allocator, start, count, value);
result.release();
return shared_ptr<T>(detail::sp_internal_constructor_tag(), start,
detail::shared_count(static_cast<detail::sp_counted_base*>(node)));
}
template<class T, class A>
inline typename enable_if_<is_unbounded_array<T>::value, shared_ptr<T> >::type
allocate_shared_noinit(const A& allocator, std::size_t count)
{
return boost::allocate_shared<T>(boost::noinit_adapt(allocator), count);
}
template<class T, class A>
inline typename enable_if_<is_bounded_array<T>::value, shared_ptr<T> >::type
allocate_shared_noinit(const A& allocator)
{
return boost::allocate_shared<T>(boost::noinit_adapt(allocator));
}
} /* boost */
#endif