/src/pdns/pdns/noinitvector.hh
Line | Count | Source |
1 | | #pragma once |
2 | | |
3 | | #include <cstdint> |
4 | | #include <memory> |
5 | | #include <new> |
6 | | #include <utility> |
7 | | #include <vector> |
8 | | |
9 | | // based on boost::core::noinit_adaptor |
10 | | // The goal is to avoid initialization of the content of a container, |
11 | | // because setting several kB of uint8_t to 0 has a real cost if you |
12 | | // do 100k times per second. |
13 | | template<class Allocator> |
14 | | struct noinit_adaptor: Allocator |
15 | | { |
16 | | template<class U> |
17 | | struct rebind { |
18 | | typedef noinit_adaptor<typename std::allocator_traits<Allocator>::template |
19 | | rebind_alloc<U> > other; |
20 | | }; |
21 | | |
22 | 1.14k | noinit_adaptor(): Allocator() { } |
23 | | |
24 | | template<class U> |
25 | | noinit_adaptor(U&& u) noexcept : Allocator(std::forward<U>(u)) { } |
26 | | |
27 | | template<class U> |
28 | | noinit_adaptor(const noinit_adaptor<U>& u) noexcept : Allocator(static_cast<const U&>(u)) { } |
29 | | |
30 | | template<class U> |
31 | 0 | void construct(U* p) { |
32 | 0 | ::new((void*)p) U; |
33 | 0 | } |
34 | | |
35 | | template<class U, class V, class... Args> |
36 | 5.17M | void construct(U* p, V&& v, Args&&... args) { |
37 | 5.17M | ::new((void*)p) U(std::forward<V>(v), std::forward<Args>(args)...); |
38 | 5.17M | } Unexecuted instantiation: void noinit_adaptor<std::__1::allocator<unsigned char> >::construct<unsigned char, unsigned char>(unsigned char*, unsigned char&&) Unexecuted instantiation: void noinit_adaptor<std::__1::allocator<unsigned char> >::construct<unsigned char, char const&>(unsigned char*, char const&) Unexecuted instantiation: void noinit_adaptor<std::__1::allocator<unsigned char> >::construct<unsigned char, unsigned char&>(unsigned char*, unsigned char&) void noinit_adaptor<std::__1::allocator<unsigned char> >::construct<unsigned char, unsigned char const&>(unsigned char*, unsigned char const&) Line | Count | Source | 36 | 5.17M | void construct(U* p, V&& v, Args&&... args) { | 37 | 5.17M | ::new((void*)p) U(std::forward<V>(v), std::forward<Args>(args)...); | 38 | 5.17M | } |
|
39 | | |
40 | | template<class U> |
41 | 5.17M | void destroy(U* p) { |
42 | 5.17M | p->~U(); |
43 | 5.17M | } |
44 | | }; |
45 | | |
46 | | template<class T, class U> |
47 | | inline bool operator==(const noinit_adaptor<T>& lhs, |
48 | | const noinit_adaptor<U>& rhs) noexcept |
49 | | { |
50 | | return static_cast<const T&>(lhs) == static_cast<const U&>(rhs); |
51 | | } |
52 | | |
53 | | template<class T, class U> |
54 | | inline bool operator!=(const noinit_adaptor<T>& lhs, |
55 | | const noinit_adaptor<U>& rhs) noexcept |
56 | | { |
57 | | return !(lhs == rhs); |
58 | | } |
59 | | |
60 | | template<class Allocator> |
61 | | inline noinit_adaptor<Allocator> noinit_adapt(const Allocator& a) noexcept |
62 | | { |
63 | | return noinit_adaptor<Allocator>(a); |
64 | | } |
65 | | |
66 | | template<class T> using NoInitVector = std::vector<T, noinit_adaptor<std::allocator<T>>>; |
67 | | |
68 | | using PacketBuffer = NoInitVector<uint8_t>; |