libs/http/include/boost/http/detail/impl/workspace.hpp

97.9% Lines (46/47) 100.0% Functions (14/14) 72.7% Branches (8/11)

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1			//
2			// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)
3			//
4			// Distributed under the Boost Software License, Version 1.0. (See accompanying
5			// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6			//
7			// Official repository: https://github.com/cppalliance/http
8			//
9
10			#ifndef BOOST_HTTP_DETAIL_IMPL_WORKSPACE_HPP
11			#define BOOST_HTTP_DETAIL_IMPL_WORKSPACE_HPP
12
13			#include <boost/config.hpp>
14
15			namespace boost {
16			namespace http {
17			namespace detail {
18
19			#if defined(BOOST_MSVC)
20			#pragma warning(push)
21			#pragma warning(disable : 4324) /* structure was padded due to __declspec(align()) */
22			#endif
23
24			struct workspace::any
25			{
26			any* next = nullptr;
27
28			BOOST_HTTP_DECL
29			virtual ~any() = 0;
30			};
31
32			template<class U>
33			struct alignas(::max_align_t)
34			workspace::any_impl : any
35			{
36			U u;
37
38			any_impl(any_impl const&) = delete;
39			any_impl(any_impl&&) = delete;
40
41			template<class... Args>
42		10	explicit any_impl(Args&&... args)
43		10	: u(std::forward<Args>(args)...)
44			{
45		10	}
46			};
47
48			struct workspace::undo
49			{
50			explicit
51		101	undo(workspace& ws0) noexcept
52		101	: ws_(ws0)
53		101	, head_(ws0.head_)
54			{
55		101	}
56
57		101	~undo()
58			{
59	1/2 ✗ Branch 0 not taken. ✓ Branch 1 taken 101 times.	101	if(head_)
60		✗	ws_.head_ = head_;
61		101	}
62
63			void
64		101	commit() noexcept
65			{
66		101	head_ = nullptr;
67		101	}
68
69			private:
70			workspace& ws_;
71			unsigned char* head_;
72			};
73
74			template<class T>
75			constexpr
76			std::size_t
77			workspace::
78			space_needed()
79			{
80			using U = typename std::decay<T>::type;
81
82			static_assert(
83			alignof(U) <= alignof(::max_align_t),
84			"Overaligned types not supported");
85
86			return sizeof(any_impl<U>);
87			}
88
89			template<class T, class... Args>
90			auto
91		10	workspace::
92			emplace(Args&&... args) ->
93			typename std::decay<T>::type&
94			{
95			static_assert(
96			alignof(T) <= alignof(::max_align_t),
97			"Overaligned types not supported");
98
99			using U = any_impl<typename
100			std::decay<T>::type>;
101
102		10	undo u(*this);
103		10	auto prev_head = head_;
104	1/1 ✓ Branch 1 taken 10 times.	10	head_ = bump_down(sizeof(U), alignof(U));
105	1/3 ✓ Branch 3 taken 10 times. ✗ Branch 5 not taken. ✗ Branch 6 not taken.	10	auto p = ::new(head_) U(
106			std::forward<Args>(args)...);
107		10	u.commit();
108		10	p->next = reinterpret_cast<
109			any*>(prev_head);
110		10	return p->u;
111		10	}
112
113			template<class T>
114			T*
115		91	workspace::
116			push_array(
117			std::size_t n,
118			T const& t)
119			{
120			struct alignas(::max_align_t)
121			U : any
122			{
123			std::size_t n_ = 0;
124
125		91	U() = default;
126		91	~U()
127			{
128		91	for(std::size_t i = n_;
129	2/2 ✓ Branch 0 taken 291 times. ✓ Branch 1 taken 91 times.	382	i-- > 0;)
130		291	data()[i].~T();
131		182	}
132
133		91	U( std::size_t n,
134			T const& t)
135		91	: U()
136			{
137	2/2 ✓ Branch 0 taken 291 times. ✓ Branch 1 taken 91 times.	382	while(n_ < n)
138			{
139		291	new(&data()[n_]) T(t);
140		291	++n_;
141			}
142		91	}
143
144		673	T* data() noexcept
145			{
146			return reinterpret_cast<
147		673	T*>(this + 1);
148			}
149			};
150
151		91	undo u(*this);
152		91	auto prev_head = head_;
153		182	head_ = bump_down(
154	1/1 ✓ Branch 1 taken 91 times.	91	sizeof(U) + n * sizeof(T),
155			alignof(::max_align_t));
156		91	auto p = ::new(head_) U(n, t);
157		91	u.commit();
158		91	p->next = reinterpret_cast<
159			any*>(prev_head);
160		182	return p->data();
161		91	}
162
163			#if defined(BOOST_MSVC)
164			#pragma warning(pop) /* C4324 */
165			#endif
166
167			} // detail
168			} // http
169			} // boost
170
171			#endif
172