blob: 2a98cda539b8cb08a03a4a7589d037fdc78b9c7d (
plain) (
blame)
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
128
129
130
131
132
133
|
// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <iterator>
#include "common/make_unique_for_overwrite.h"
namespace Common {
/**
* ScratchBuffer class
* This class creates a default initialized heap allocated buffer for cases such as intermediate
* buffers being copied into entirely, where value initializing members during allocation or resize
* is redundant.
*/
template <typename T>
class ScratchBuffer {
public:
using element_type = T;
using value_type = T;
using size_type = size_t;
using difference_type = std::ptrdiff_t;
using pointer = T*;
using const_pointer = const T*;
using reference = T&;
using const_reference = const T&;
using iterator = pointer;
using const_iterator = const_pointer;
using iterator_category = std::random_access_iterator_tag;
using iterator_concept = std::contiguous_iterator_tag;
ScratchBuffer() = default;
explicit ScratchBuffer(size_type initial_capacity)
: last_requested_size{initial_capacity}, buffer_capacity{initial_capacity},
buffer{Common::make_unique_for_overwrite<T[]>(initial_capacity)} {}
~ScratchBuffer() = default;
ScratchBuffer(const ScratchBuffer&) = delete;
ScratchBuffer& operator=(const ScratchBuffer&) = delete;
ScratchBuffer(ScratchBuffer&& other) noexcept {
swap(other);
other.last_requested_size = 0;
other.buffer_capacity = 0;
other.buffer.reset();
}
ScratchBuffer& operator=(ScratchBuffer&& other) noexcept {
swap(other);
other.last_requested_size = 0;
other.buffer_capacity = 0;
other.buffer.reset();
return *this;
}
/// This will only grow the buffer's capacity if size is greater than the current capacity.
/// The previously held data will remain intact.
void resize(size_type size) {
if (size > buffer_capacity) {
auto new_buffer = Common::make_unique_for_overwrite<T[]>(size);
std::move(buffer.get(), buffer.get() + buffer_capacity, new_buffer.get());
buffer = std::move(new_buffer);
buffer_capacity = size;
}
last_requested_size = size;
}
/// This will only grow the buffer's capacity if size is greater than the current capacity.
/// The previously held data will be destroyed if a reallocation occurs.
void resize_destructive(size_type size) {
if (size > buffer_capacity) {
buffer_capacity = size;
buffer = Common::make_unique_for_overwrite<T[]>(buffer_capacity);
}
last_requested_size = size;
}
[[nodiscard]] pointer data() noexcept {
return buffer.get();
}
[[nodiscard]] const_pointer data() const noexcept {
return buffer.get();
}
[[nodiscard]] iterator begin() noexcept {
return data();
}
[[nodiscard]] const_iterator begin() const noexcept {
return data();
}
[[nodiscard]] iterator end() noexcept {
return data() + last_requested_size;
}
[[nodiscard]] const_iterator end() const noexcept {
return data() + last_requested_size;
}
[[nodiscard]] reference operator[](size_type i) {
return buffer[i];
}
[[nodiscard]] const_reference operator[](size_type i) const {
return buffer[i];
}
[[nodiscard]] size_type size() const noexcept {
return last_requested_size;
}
[[nodiscard]] size_type capacity() const noexcept {
return buffer_capacity;
}
void swap(ScratchBuffer& other) noexcept {
std::swap(last_requested_size, other.last_requested_size);
std::swap(buffer_capacity, other.buffer_capacity);
std::swap(buffer, other.buffer);
}
private:
size_type last_requested_size{};
size_type buffer_capacity{};
std::unique_ptr<T[]> buffer{};
};
} // namespace Common
|
