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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2025
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/utils/buffer.h"
#include "td/utils/logging.h"
#include "td/utils/port/thread_local.h"
#include <cstddef>
#include <new>
// fixes https://bugs.llvm.org/show_bug.cgi?id=33723 for clang >= 3.6 + c++11 + libc++
#if TD_CLANG && _LIBCPP_VERSION
#define TD_OFFSETOF __builtin_offsetof
#else
#define TD_OFFSETOF offsetof
#endif
namespace td {
TD_THREAD_LOCAL BufferAllocator::BufferRawTls *BufferAllocator::buffer_raw_tls; // static zero-initialized
std::atomic<size_t> BufferAllocator::buffer_mem;
int64 BufferAllocator::get_buffer_slice_size() {
return 0;
}
size_t BufferAllocator::get_buffer_mem() {
return buffer_mem;
}
BufferAllocator::WriterPtr BufferAllocator::create_writer(size_t size) {
if (size < 512) {
size = 512;
}
return create_writer_exact(size);
}
BufferAllocator::WriterPtr BufferAllocator::create_writer_exact(size_t size) {
return WriterPtr(create_buffer_raw(size));
}
BufferAllocator::WriterPtr BufferAllocator::create_writer(size_t size, size_t prepend, size_t append) {
auto ptr = create_writer(size + prepend + append);
ptr->begin_ += prepend;
ptr->end_ += prepend + size;
return ptr;
}
BufferAllocator::ReaderPtr BufferAllocator::create_reader(size_t size) {
if (size < 512) {
return create_reader_fast(size);
}
auto ptr = create_writer_exact(size);
ptr->end_ += (size + 7) & -8;
return create_reader(ptr);
}
BufferAllocator::ReaderPtr BufferAllocator::create_reader_fast(size_t size) {
size = (size + 7) & -8;
init_thread_local<BufferRawTls>(buffer_raw_tls);
auto buffer_raw = buffer_raw_tls->buffer_raw.get();
if (buffer_raw == nullptr || buffer_raw->data_size_ - buffer_raw->end_.load(std::memory_order_relaxed) < size) {
buffer_raw = create_buffer_raw(4096 * 4);
buffer_raw_tls->buffer_raw = std::unique_ptr<BufferRaw, BufferAllocator::BufferRawDeleter>(buffer_raw);
}
buffer_raw->end_.fetch_add(size, std::memory_order_relaxed);
buffer_raw->ref_cnt_.fetch_add(1, std::memory_order_acq_rel);
return ReaderPtr(buffer_raw);
}
BufferAllocator::ReaderPtr BufferAllocator::create_reader(const WriterPtr &raw) {
raw->was_reader_ = true;
raw->ref_cnt_.fetch_add(1, std::memory_order_acq_rel);
return ReaderPtr(raw.get());
}
BufferAllocator::ReaderPtr BufferAllocator::create_reader(const ReaderPtr &raw) {
raw->ref_cnt_.fetch_add(1, std::memory_order_acq_rel);
return ReaderPtr(raw.get());
}
void BufferAllocator::dec_ref_cnt(BufferRaw *ptr) {
int left = ptr->ref_cnt_.fetch_sub(1, std::memory_order_acq_rel);
if (left == 1) {
auto buf_size = max(sizeof(BufferRaw), TD_OFFSETOF(BufferRaw, data_) + ptr->data_size_);
buffer_mem -= buf_size;
ptr->~BufferRaw();
delete[] ptr;
}
}
size_t ChainBufferReader::advance(size_t offset, MutableSlice dest) {
LOG_CHECK(offset <= size()) << offset << " " << size() << " " << end_.offset() << " " << begin_.offset() << " "
<< sync_flag_ << " " << dest.size();
return begin_.advance(offset, dest);
}
BufferRaw *BufferAllocator::create_buffer_raw(size_t size) {
size = (size + 7) & -8;
auto buf_size = TD_OFFSETOF(BufferRaw, data_) + size;
if (buf_size < sizeof(BufferRaw)) {
buf_size = sizeof(BufferRaw);
}
buffer_mem += buf_size;
auto *buffer_raw = reinterpret_cast<BufferRaw *>(new char[buf_size]);
return new (buffer_raw) BufferRaw(size);
}
void BufferBuilder::append(BufferSlice slice) {
if (append_inplace(slice.as_slice())) {
return;
}
append_slow(std::move(slice));
}
void BufferBuilder::append(Slice slice) {
if (append_inplace(slice)) {
return;
}
append_slow(BufferSlice(slice));
}
void BufferBuilder::prepend(BufferSlice slice) {
if (prepend_inplace(slice.as_slice())) {
return;
}
prepend_slow(std::move(slice));
}
void BufferBuilder::prepend(Slice slice) {
if (prepend_inplace(slice)) {
return;
}
prepend_slow(BufferSlice(slice));
}
BufferSlice BufferBuilder::extract() {
if (to_append_.empty() && to_prepend_.empty()) {
return buffer_writer_.as_buffer_slice();
}
size_t total_size = size();
BufferWriter writer(0, 0, total_size);
std::move(*this).for_each([&](auto &&slice) {
writer.prepare_append().truncate(slice.size()).copy_from(slice.as_slice());
writer.confirm_append(slice.size());
});
*this = {};
return writer.as_buffer_slice();
}
size_t BufferBuilder::size() const {
size_t total_size = 0;
for_each([&](auto &&slice) { total_size += slice.size(); });
return total_size;
}
bool BufferBuilder::append_inplace(Slice slice) {
if (!to_append_.empty()) {
return false;
}
auto dest = buffer_writer_.prepare_append();
if (dest.size() < slice.size()) {
return false;
}
dest.remove_suffix(dest.size() - slice.size());
dest.copy_from(slice);
buffer_writer_.confirm_append(slice.size());
return true;
}
void BufferBuilder::append_slow(BufferSlice slice) {
to_append_.push_back(std::move(slice));
}
bool BufferBuilder::prepend_inplace(Slice slice) {
if (!to_prepend_.empty()) {
return false;
}
auto dest = buffer_writer_.prepare_prepend();
if (dest.size() < slice.size()) {
return false;
}
dest.remove_prefix(dest.size() - slice.size());
dest.copy_from(slice);
buffer_writer_.confirm_prepend(slice.size());
return true;
}
void BufferBuilder::prepend_slow(BufferSlice slice) {
to_prepend_.push_back(std::move(slice));
}
} // namespace td
|
