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
content / renderer / mhtml_handle_writer.cc [blame]
// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/342213636): Remove this and spanify to fix the errors.
#pragma allow_unsafe_buffers
#endif
#include "content/renderer/mhtml_handle_writer.h"
#include "base/containers/span.h"
#include "base/metrics/histogram_macros.h"
#include "base/task/sequenced_task_runner.h"
#include "base/task/task_traits.h"
#include "base/task/thread_pool.h"
#include "base/trace_event/trace_event.h"
#include "content/common/download/mhtml_file_writer.mojom.h"
#include "content/public/renderer/render_thread.h"
#include "third_party/blink/public/platform/web_thread_safe_data.h"
namespace content {
MHTMLHandleWriter::MHTMLHandleWriter(
scoped_refptr<base::TaskRunner> main_thread_task_runner,
MHTMLWriteCompleteCallback callback)
: main_thread_task_runner_(std::move(main_thread_task_runner)),
callback_(std::move(callback)) {}
MHTMLHandleWriter::~MHTMLHandleWriter() {}
void MHTMLHandleWriter::WriteContents(
std::vector<blink::WebThreadSafeData> mhtml_contents) {
TRACE_EVENT_NESTABLE_ASYNC_BEGIN0("page-serialization",
"Writing MHTML contents to handle",
TRACE_ID_LOCAL(this));
is_writing_ = true;
WriteContentsImpl(std::move(mhtml_contents));
}
void MHTMLHandleWriter::Finish(mojom::MhtmlSaveStatus save_status) {
DCHECK(!RenderThread::IsMainThread())
<< "Should not run in the main renderer thread";
if (is_writing_) {
TRACE_EVENT_NESTABLE_ASYNC_END0("page-serialization",
"WriteContentsImpl (MHTMLHandleWriter)",
TRACE_ID_LOCAL(this));
}
Close();
main_thread_task_runner_->PostTask(
FROM_HERE, base::BindOnce(std::move(callback_), save_status));
}
MHTMLFileHandleWriter::MHTMLFileHandleWriter(
scoped_refptr<base::TaskRunner> main_thread_task_runner,
MHTMLWriteCompleteCallback callback,
base::File file)
: MHTMLHandleWriter(std::move(main_thread_task_runner),
std::move(callback)),
file_(std::move(file)) {
#if BUILDFLAG(IS_FUCHSIA)
// TODO(crbug.com/42050414): Remove the Seek call.
// On fuchsia, fds do not share state. As the fd has been duped and sent from
// the browser process, it must be seeked to the end to ensure the data is
// appended.
file_.Seek(base::File::FROM_END, 0);
#endif // BUILDFLAG(IS_FUCHSIA)
}
MHTMLFileHandleWriter::~MHTMLFileHandleWriter() {}
void MHTMLFileHandleWriter::WriteContentsImpl(
std::vector<blink::WebThreadSafeData> mhtml_contents) {
for (const auto& data : mhtml_contents) {
if (data.IsEmpty()) {
continue;
}
if (!file_.WriteAtCurrentPosAndCheck(base::as_byte_span(data))) {
Finish(mojom::MhtmlSaveStatus::kFileWritingError);
return;
}
}
Finish(mojom::MhtmlSaveStatus::kSuccess);
}
void MHTMLFileHandleWriter::Close() {
file_.Close();
}
MHTMLProducerHandleWriter::MHTMLProducerHandleWriter(
scoped_refptr<base::TaskRunner> main_thread_task_runner,
MHTMLWriteCompleteCallback callback,
mojo::ScopedDataPipeProducerHandle producer)
: MHTMLHandleWriter(std::move(main_thread_task_runner),
std::move(callback)),
producer_(std::move(producer)),
current_block_(0),
write_position_(0) {}
void MHTMLProducerHandleWriter::WriteContentsImpl(
std::vector<blink::WebThreadSafeData> mhtml_contents) {
DCHECK(mhtml_contents_.empty());
mhtml_contents_ = std::move(mhtml_contents);
scoped_refptr<base::SequencedTaskRunner> task_runner =
base::ThreadPool::CreateSequencedTaskRunner(
{base::MayBlock(), base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN});
task_runner->PostTask(
FROM_HERE, base::BindOnce(&MHTMLProducerHandleWriter::BeginWatchingHandle,
base::Unretained(this)));
}
MHTMLProducerHandleWriter::~MHTMLProducerHandleWriter() {}
void MHTMLProducerHandleWriter::Close() {
producer_.reset();
}
void MHTMLProducerHandleWriter::BeginWatchingHandle() {
// mojo::SimpleWatcher's constructor by default gets a reference ptr
// to the current SequencedTaskRunner if one is not specified, keeping
// the current SequencedTaskRunner's lifetime bound to |watcher_|.
watcher_ = std::make_unique<mojo::SimpleWatcher>(
FROM_HERE, mojo::SimpleWatcher::ArmingPolicy::AUTOMATIC);
// Using base::Unretained is safe, as |this| owns |watcher_|.
watcher_->Watch(
producer_.get(),
MOJO_HANDLE_SIGNAL_WRITABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED,
MOJO_WATCH_CONDITION_SATISFIED,
base::BindRepeating(&MHTMLProducerHandleWriter::TryWritingContents,
base::Unretained(this)));
}
// TODO(crbug.com/40606905): This can be simplified with usage
// of BlockingCopyToString once error signalling is implemented and
// updated with usage of base::span instead of std::string.
void MHTMLProducerHandleWriter::TryWritingContents(
MojoResult result,
const mojo::HandleSignalsState& state) {
if (result != MOJO_RESULT_OK) {
DLOG(ERROR)
<< "Error receiving notifications from producer handle watcher.";
Finish(mojom::MhtmlSaveStatus::kStreamingError);
return;
}
while (true) {
const blink::WebThreadSafeData& data = mhtml_contents_.at(current_block_);
base::span<const uint8_t> bytes =
base::as_byte_span(data).subspan(write_position_);
// If there is no more data in this block, continue to next block or
// finish.
if (bytes.empty()) {
write_position_ = 0;
if (++current_block_ >= mhtml_contents_.size()) {
Finish(mojom::MhtmlSaveStatus::kSuccess);
return;
}
continue;
}
size_t bytes_written = 0;
result =
producer_->WriteData(bytes, MOJO_WRITE_DATA_FLAG_NONE, bytes_written);
// Break out of loop early if write was not successful to avoid
// incrementing the write position incorrectly.
if (result != MOJO_RESULT_OK)
break;
// Reaching this indicates a successful write.
write_position_ += bytes_written;
DCHECK(write_position_ <= data.size());
}
if (result != MOJO_RESULT_SHOULD_WAIT) {
Finish(mojom::MhtmlSaveStatus::kStreamingError);
}
// Buffer is full, return to automatically re-arm the watcher.
}
} // namespace content