1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
#pragma clang system_header
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
#pragma once
#include <cstring>
#include <type_traits>
#include <utility>
#include "contrib/libs/apache/arrow_next/cpp/src/arrow/util/launder.h"
#include "contrib/libs/apache/arrow_next/cpp/src/arrow/util/macros.h"
namespace arrow20 {
namespace internal {
template <typename T>
class AlignedStorage {
public:
static constexpr bool can_memcpy = std::is_trivial<T>::value;
constexpr T* get() noexcept {
return arrow20::internal::launder(reinterpret_cast<T*>(&data_));
}
constexpr const T* get() const noexcept {
// Use fully qualified name to avoid ambiguities with MSVC (ARROW-14800)
return arrow20::internal::launder(reinterpret_cast<const T*>(&data_));
}
void destroy() noexcept {
if (!std::is_trivially_destructible<T>::value) {
get()->~T();
}
}
template <typename... A>
void construct(A&&... args) noexcept {
new (&data_) T(std::forward<A>(args)...);
}
template <typename V>
void assign(V&& v) noexcept {
*get() = std::forward<V>(v);
}
void move_construct(AlignedStorage* other) noexcept {
new (&data_) T(std::move(*other->get()));
}
void move_assign(AlignedStorage* other) noexcept { *get() = std::move(*other->get()); }
template <bool CanMemcpy = can_memcpy>
static typename std::enable_if<CanMemcpy>::type move_construct_several(
AlignedStorage* ARROW_RESTRICT src, AlignedStorage* ARROW_RESTRICT dest, size_t n,
size_t memcpy_length) noexcept {
memcpy(dest->get(), src->get(), memcpy_length * sizeof(T));
}
template <bool CanMemcpy = can_memcpy>
static typename std::enable_if<CanMemcpy>::type
move_construct_several_and_destroy_source(AlignedStorage* ARROW_RESTRICT src,
AlignedStorage* ARROW_RESTRICT dest, size_t n,
size_t memcpy_length) noexcept {
memcpy(dest->get(), src->get(), memcpy_length * sizeof(T));
}
template <bool CanMemcpy = can_memcpy>
static typename std::enable_if<!CanMemcpy>::type move_construct_several(
AlignedStorage* ARROW_RESTRICT src, AlignedStorage* ARROW_RESTRICT dest, size_t n,
size_t memcpy_length) noexcept {
for (size_t i = 0; i < n; ++i) {
new (dest[i].get()) T(std::move(*src[i].get()));
}
}
template <bool CanMemcpy = can_memcpy>
static typename std::enable_if<!CanMemcpy>::type
move_construct_several_and_destroy_source(AlignedStorage* ARROW_RESTRICT src,
AlignedStorage* ARROW_RESTRICT dest, size_t n,
size_t memcpy_length) noexcept {
for (size_t i = 0; i < n; ++i) {
new (dest[i].get()) T(std::move(*src[i].get()));
src[i].destroy();
}
}
static void move_construct_several(AlignedStorage* ARROW_RESTRICT src,
AlignedStorage* ARROW_RESTRICT dest,
size_t n) noexcept {
move_construct_several(src, dest, n, n);
}
static void move_construct_several_and_destroy_source(
AlignedStorage* ARROW_RESTRICT src, AlignedStorage* ARROW_RESTRICT dest,
size_t n) noexcept {
move_construct_several_and_destroy_source(src, dest, n, n);
}
static void destroy_several(AlignedStorage* p, size_t n) noexcept {
if (!std::is_trivially_destructible<T>::value) {
for (size_t i = 0; i < n; ++i) {
p[i].destroy();
}
}
}
private:
alignas(T) std::byte data_[sizeof(T)];
};
} // namespace internal
} // namespace arrow20
|
