blob: d7ad9102de31f0e5850de439640b473bdb413083 [file] [log] [blame]
// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/log/file_net_log_observer.h"
#include <algorithm>
#include <memory>
#include <queue>
#include <string>
#include <utility>
#include "base/bind.h"
#include "base/files/file_util.h"
#include "base/json/json_writer.h"
#include "base/logging.h"
#include "base/sequenced_task_runner.h"
#include "base/strings/string_number_conversions.h"
#include "base/synchronization/lock.h"
#include "base/task_scheduler/post_task.h"
#include "base/values.h"
#include "net/log/net_log_capture_mode.h"
#include "net/log/net_log_entry.h"
#include "net/log/net_log_util.h"
#include "net/url_request/url_request_context.h"
namespace {
// Number of events that can build up in |write_queue_| before a task is posted
// to the file task runner to flush them to disk.
const int kNumWriteQueueEvents = 15;
scoped_refptr<base::SequencedTaskRunner> CreateFileTaskRunner() {
// The tasks posted to this sequenced task runner do synchronous File I/O for
// the purposes of writing NetLog files.
//
// These intentionally block shutdown to ensure the log file has finished
// being written.
return base::CreateSequencedTaskRunnerWithTraits(
{base::MayBlock(), base::TaskPriority::USER_VISIBLE,
base::TaskShutdownBehavior::BLOCK_SHUTDOWN});
}
// Opens |path| in write mode. Returns the file handle on success, or nullptr on
// failure.
base::ScopedFILE OpenFileForWrite(const base::FilePath& path) {
base::ScopedFILE result(base::OpenFile(path, "wb"));
LOG_IF(ERROR, !result) << "Failed opening: " << path.value();
return result;
}
// Helper that writes data to a file. The |file| handle may optionally be null,
// in which case nothing will be written. Returns the number of bytes
// successfully written (may be less than input data in case of errors).
size_t WriteToFile(FILE* file,
base::StringPiece data1,
base::StringPiece data2 = base::StringPiece(),
base::StringPiece data3 = base::StringPiece()) {
size_t bytes_written = 0;
if (file) {
// Append each of data1, data2 and data3.
if (!data1.empty())
bytes_written += fwrite(data1.data(), 1, data1.size(), file);
if (!data2.empty())
bytes_written += fwrite(data2.data(), 1, data2.size(), file);
if (!data3.empty())
bytes_written += fwrite(data3.data(), 1, data3.size(), file);
}
return bytes_written;
}
// Copies all of the data at |source_path| and appends it to |destination_file|,
// then deletes |source_path|.
void AppendToFileThenDelete(const base::FilePath& source_path,
FILE* destination_file,
char* read_buffer,
size_t read_buffer_size) {
base::ScopedFILE source_file(base::OpenFile(source_path, "rb"));
if (!source_file)
return;
// Read |source_path|'s contents in chunks of read_buffer_size and append
// to |destination_file|.
size_t num_bytes_read;
while ((num_bytes_read =
fread(read_buffer, 1, read_buffer_size, source_file.get())) > 0) {
WriteToFile(destination_file,
base::StringPiece(read_buffer, num_bytes_read));
}
// Now that it has been copied, delete the source file.
source_file.reset();
base::DeleteFile(source_path, false);
}
} // namespace
namespace net {
// Used to store events to be written to file.
using EventQueue = std::queue<std::unique_ptr<std::string>>;
// WriteQueue receives events from FileNetLogObserver on the main thread and
// holds them in a queue until they are drained from the queue and written to
// file on the file task runner.
//
// WriteQueue contains the resources shared between the main thread and the
// file task runner. |lock_| must be acquired to read or write to |queue_| and
// |memory_|.
//
// WriteQueue is refcounted and should be destroyed once all events on the
// file task runner have finished executing.
class FileNetLogObserver::WriteQueue
: public base::RefCountedThreadSafe<WriteQueue> {
public:
// |memory_max| indicates the maximum amount of memory that the virtual write
// queue can use. If |memory_| exceeds |memory_max_|, the |queue_| of events
// is overwritten.
explicit WriteQueue(size_t memory_max);
// Adds |event| to |queue_|. Also manages the size of |memory_|; if it
// exceeds |memory_max_|, then old events are dropped from |queue_| without
// being written to file.
//
// Returns the number of events in the |queue_|.
size_t AddEntryToQueue(std::unique_ptr<std::string> event);
// Swaps |queue_| with |local_queue|. |local_queue| should be empty, so that
// |queue_| is emptied. Resets |memory_| to 0.
void SwapQueue(EventQueue* local_queue);
private:
friend class base::RefCountedThreadSafe<WriteQueue>;
~WriteQueue();
// Queue of events to be written, shared between main thread and file task
// runner. Main thread adds events to the queue and the file task runner
// drains them and writes the events to file.
//
// |lock_| must be acquired to read or write to this.
EventQueue queue_;
// Tracks how much memory is being used by the virtual write queue.
// Incremented in AddEntryToQueue() when events are added to the
// buffer, and decremented when SwapQueue() is called and the file task
// runner's local queue is swapped with the shared write queue.
//
// |lock_| must be acquired to read or write to this.
size_t memory_;
// Indicates the maximum amount of memory that the |queue_| is allowed to
// use.
const size_t memory_max_;
// Protects access to |queue_| and |memory_|.
//
// A lock is necessary because |queue_| and |memory_| are shared between the
// file task runner and the main thread. NetLog's lock protects OnAddEntry(),
// which calls AddEntryToQueue(), but it does not protect access to the
// observer's member variables. Thus, a race condition exists if a thread is
// calling OnAddEntry() at the same time that the file task runner is
// accessing |memory_| and |queue_| to write events to file. The |queue_| and
// |memory_| counter are necessary to bound the amount of memory that is used
// for the queue in the event that the file task runner lags significantly
// behind the main thread in writing events to file.
base::Lock lock_;
DISALLOW_COPY_AND_ASSIGN(WriteQueue);
};
// FileWriter is responsible for draining events from a WriteQueue and writing
// them to disk. FileWriter can be constructed on any thread, and
// afterwards is only accessed on the file task runner.
class FileNetLogObserver::FileWriter {
public:
// If max_event_file_size == kNoLimit, then no limit is enforced.
FileWriter(const base::FilePath& log_path,
size_t max_event_file_size,
size_t total_num_event_files,
scoped_refptr<base::SequencedTaskRunner> task_runner);
~FileWriter();
// Writes |constants_value| to disk and opens the events array (closed in
// Stop()).
void Initialize(std::unique_ptr<base::Value> constants_value);
// Closes the events array opened in Initialize() and writes |polled_data| to
// disk. If |polled_data| cannot be converted to proper JSON, then it
// is ignored.
void Stop(std::unique_ptr<base::Value> polled_data);
// Drains |queue_| from WriteQueue into a local file queue and writes the
// events in the queue to disk.
void Flush(scoped_refptr<WriteQueue> write_queue);
// Deletes all netlog files. It is not valid to call any method of
// FileNetLogObserver after DeleteAllFiles().
void DeleteAllFiles();
void FlushThenStop(scoped_refptr<WriteQueue> write_queue,
std::unique_ptr<base::Value> polled_data);
private:
// Returns true if there is no file size bound to enforce.
//
// When operating in unbounded mode, the implementation is optimized to stream
// writes to a single file, rather than chunking them across temporary event
// files.
bool IsUnbounded() const;
bool IsBounded() const;
// Increments |current_event_file_number_|, and updates all state relating to
// the current event file (open file handle, num bytes written, current file
// number).
void IncrementCurrentEventFile();
// Gets the path to a (temporary) directory where files are written in bounded
// mode. When logging is stopped these files are stitched together and written
// to the final log path.
base::FilePath GetInprogressDirectory() const;
// Returns the path to the event file having |index|. This looks like
// "LOGDIR/event_file_<index>.json".
base::FilePath GetEventFilePath(size_t index) const;
// Gets the file path where constants are saved at the start of
// logging. This looks like "LOGDIR/constants.json".
base::FilePath GetConstantsFilePath() const;
// Gets the file path where the final data is written at the end of logging.
// This looks like "LOGDIR/end_netlog.json".
base::FilePath GetClosingFilePath() const;
// Returns the corresponding index for |file_number|. File "numbers" are a
// monotonically increasing identifier that start at 1 (a value of zero means
// it is uninitialized), whereas the file "index" is a bounded value that
// wraps and identifies the file path to use.
//
// Keeping track of the current number rather than index makes it a bit easier
// to assemble a file at the end, since it is unambiguous which paths have
// been used/re-used.
size_t FileNumberToIndex(size_t file_number) const;
// Writes |constants_value| to a file.
static void WriteConstantsToFile(std::unique_ptr<base::Value> constants_value,
FILE* file);
// Writes |polled_data| to a file.
static void WritePolledDataToFile(std::unique_ptr<base::Value> polled_data,
FILE* file);
// If any events were written (wrote_event_bytes_), rewinds |file| by 2 bytes
// in order to overwrite the trailing ",\n" that was written by the last event
// line.
void RewindIfWroteEventBytes(FILE* file) const;
// Concatenates all the log files to assemble the final
// |final_log_file_|. This single "stitched" file is what other
// log ingesting tools expect.
void StitchFinalLogFile();
// Creates the .inprogress directory used by bounded mode.
void CreateInprogressDirectory() const;
// The path (and associated file handle) where the final netlog is written. In
// bounded mode this is mostly written to once logging is stopped, whereas in
// unbounded mode events will be directly written to it.
const base::FilePath final_log_path_;
base::ScopedFILE final_log_file_;
// Holds the file handle for the numbered events file where data is currently
// being written to. The file path of this file is
// GetEventFilePath(current_event_file_number_). The
// file handle may be null if an error previously occurred opening the file,
// or logging has been stopped.
base::ScopedFILE current_event_file_;
size_t current_event_file_size_;
// Indicates the total number of netlog event files allowed.
// (The files GetConstantsFilePath() and GetClosingFilePath() do
// not count against the total.)
const size_t total_num_event_files_;
// Counter for the events file currently being written into. See
// FileNumberToIndex() for an explanation of what "number" vs "index" mean.
size_t current_event_file_number_;
// Indicates the maximum size of each individual events file. May be kNoLimit
// to indicate that it can grow arbitrarily large.
const size_t max_event_file_size_;
// Whether any bytes were written for events. This is used to properly format
// JSON (events list shouldn't end with a comma).
bool wrote_event_bytes_;
// Task runner for doing file operations.
const scoped_refptr<base::SequencedTaskRunner> task_runner_;
DISALLOW_COPY_AND_ASSIGN(FileWriter);
};
std::unique_ptr<FileNetLogObserver> FileNetLogObserver::CreateBounded(
const base::FilePath& log_path,
size_t max_total_size,
std::unique_ptr<base::Value> constants) {
// TODO(eroman): Should use something other than 10 for number of files?
return CreateBoundedInternal(log_path, max_total_size, 10,
std::move(constants));
}
std::unique_ptr<FileNetLogObserver> FileNetLogObserver::CreateUnbounded(
const base::FilePath& log_path,
std::unique_ptr<base::Value> constants) {
return CreateBounded(log_path, kNoLimit, std::move(constants));
}
FileNetLogObserver::~FileNetLogObserver() {
if (net_log()) {
// StopObserving was not called.
net_log()->RemoveObserver(this);
file_task_runner_->PostTask(
FROM_HERE, base::Bind(&FileNetLogObserver::FileWriter::DeleteAllFiles,
base::Unretained(file_writer_.get())));
}
file_task_runner_->DeleteSoon(FROM_HERE, file_writer_.release());
}
void FileNetLogObserver::StartObserving(NetLog* net_log,
NetLogCaptureMode capture_mode) {
net_log->AddObserver(this, capture_mode);
}
void FileNetLogObserver::StopObserving(std::unique_ptr<base::Value> polled_data,
base::OnceClosure optional_callback) {
net_log()->RemoveObserver(this);
base::OnceClosure bound_flush_then_stop =
base::Bind(&FileNetLogObserver::FileWriter::FlushThenStop,
base::Unretained(file_writer_.get()), write_queue_,
base::Passed(&polled_data));
// Note that PostTaskAndReply() requires a non-null closure.
if (!optional_callback.is_null()) {
file_task_runner_->PostTaskAndReply(FROM_HERE,
std::move(bound_flush_then_stop),
std::move(optional_callback));
} else {
file_task_runner_->PostTask(FROM_HERE, std::move(bound_flush_then_stop));
}
}
void FileNetLogObserver::OnAddEntry(const NetLogEntry& entry) {
std::unique_ptr<std::string> json(new std::string);
// If |entry| cannot be converted to proper JSON, ignore it.
if (!base::JSONWriter::Write(*entry.ToValue(), json.get()))
return;
size_t queue_size = write_queue_->AddEntryToQueue(std::move(json));
// If events build up in |write_queue_|, trigger the file task runner to drain
// the queue. Because only 1 item is added to the queue at a time, if
// queue_size > kNumWriteQueueEvents a task has already been posted, or will
// be posted.
if (queue_size == kNumWriteQueueEvents) {
file_task_runner_->PostTask(
FROM_HERE,
base::Bind(&FileNetLogObserver::FileWriter::Flush,
base::Unretained(file_writer_.get()), write_queue_));
}
}
std::unique_ptr<FileNetLogObserver> FileNetLogObserver::CreateBoundedForTests(
const base::FilePath& log_path,
size_t max_total_size,
size_t total_num_event_files,
std::unique_ptr<base::Value> constants) {
return CreateBoundedInternal(log_path, max_total_size, total_num_event_files,
std::move(constants));
}
std::unique_ptr<FileNetLogObserver> FileNetLogObserver::CreateBoundedInternal(
const base::FilePath& log_path,
size_t max_total_size,
size_t total_num_event_files,
std::unique_ptr<base::Value> constants) {
DCHECK_GT(total_num_event_files, 0u);
scoped_refptr<base::SequencedTaskRunner> file_task_runner =
CreateFileTaskRunner();
const size_t max_event_file_size =
max_total_size == kNoLimit ? kNoLimit
: max_total_size / total_num_event_files;
// The FileWriter uses a soft limit to write events to file that allows
// the size of the file to exceed the limit, but the WriteQueue uses a hard
// limit which the size of |WriteQueue::queue_| cannot exceed. Thus, the
// FileWriter may write more events to file than can be contained by
// the WriteQueue if they have the same size limit. The maximum size of the
// WriteQueue is doubled to allow |WriteQueue::queue_| to hold enough events
// for the FileWriter to fill all files. As long as all events have
// sizes <= the size of an individual event file, the discrepancy between the
// hard limit and the soft limit will not cause an issue.
// TODO(dconnol): Handle the case when the WriteQueue still doesn't
// contain enough events to fill all files, because of very large events
// relative to file size.
std::unique_ptr<FileWriter> file_writer(new FileWriter(
log_path, max_event_file_size, total_num_event_files, file_task_runner));
scoped_refptr<WriteQueue> write_queue(new WriteQueue(max_total_size * 2));
return std::unique_ptr<FileNetLogObserver>(
new FileNetLogObserver(file_task_runner, std::move(file_writer),
std::move(write_queue), std::move(constants)));
}
FileNetLogObserver::FileNetLogObserver(
scoped_refptr<base::SequencedTaskRunner> file_task_runner,
std::unique_ptr<FileWriter> file_writer,
scoped_refptr<WriteQueue> write_queue,
std::unique_ptr<base::Value> constants)
: file_task_runner_(std::move(file_task_runner)),
write_queue_(std::move(write_queue)),
file_writer_(std::move(file_writer)) {
if (!constants)
constants = GetNetConstants();
file_task_runner_->PostTask(
FROM_HERE, base::Bind(&FileNetLogObserver::FileWriter::Initialize,
base::Unretained(file_writer_.get()),
base::Passed(&constants)));
}
FileNetLogObserver::WriteQueue::WriteQueue(size_t memory_max)
: memory_(0), memory_max_(memory_max) {}
size_t FileNetLogObserver::WriteQueue::AddEntryToQueue(
std::unique_ptr<std::string> event) {
base::AutoLock lock(lock_);
memory_ += event->size();
queue_.push(std::move(event));
while (memory_ > memory_max_ && !queue_.empty()) {
// Delete oldest events in the queue.
DCHECK(queue_.front());
memory_ -= queue_.front()->size();
queue_.pop();
}
return queue_.size();
}
void FileNetLogObserver::WriteQueue::SwapQueue(EventQueue* local_queue) {
DCHECK(local_queue->empty());
base::AutoLock lock(lock_);
queue_.swap(*local_queue);
memory_ = 0;
}
FileNetLogObserver::WriteQueue::~WriteQueue() {}
FileNetLogObserver::FileWriter::FileWriter(
const base::FilePath& log_path,
size_t max_event_file_size,
size_t total_num_event_files,
scoped_refptr<base::SequencedTaskRunner> task_runner)
: final_log_path_(log_path),
total_num_event_files_(total_num_event_files),
current_event_file_number_(0),
max_event_file_size_(max_event_file_size),
wrote_event_bytes_(false),
task_runner_(std::move(task_runner)) {}
FileNetLogObserver::FileWriter::~FileWriter() {}
void FileNetLogObserver::FileWriter::Initialize(
std::unique_ptr<base::Value> constants_value) {
DCHECK(task_runner_->RunsTasksInCurrentSequence());
// Open the final log file, and keep it open for the duration of logging (even
// in bounded mode).
final_log_file_ = OpenFileForWrite(final_log_path_);
if (IsBounded()) {
CreateInprogressDirectory();
base::ScopedFILE constants_file = OpenFileForWrite(GetConstantsFilePath());
WriteConstantsToFile(std::move(constants_value), constants_file.get());
} else {
WriteConstantsToFile(std::move(constants_value), final_log_file_.get());
}
}
void FileNetLogObserver::FileWriter::Stop(
std::unique_ptr<base::Value> polled_data) {
DCHECK(task_runner_->RunsTasksInCurrentSequence());
// Write out the polled data.
if (IsBounded()) {
base::ScopedFILE closing_file = OpenFileForWrite(GetClosingFilePath());
WritePolledDataToFile(std::move(polled_data), closing_file.get());
} else {
RewindIfWroteEventBytes(final_log_file_.get());
WritePolledDataToFile(std::move(polled_data), final_log_file_.get());
}
// If operating in bounded mode, the events were written to separate files
// within GetInprogressDirectory(). Assemble them into the final destination
// file.
if (IsBounded())
StitchFinalLogFile();
// Ensure the final log file has been flushed.
final_log_file_.reset();
}
void FileNetLogObserver::FileWriter::Flush(
scoped_refptr<FileNetLogObserver::WriteQueue> write_queue) {
DCHECK(task_runner_->RunsTasksInCurrentSequence());
EventQueue local_file_queue;
write_queue->SwapQueue(&local_file_queue);
while (!local_file_queue.empty()) {
FILE* output_file;
// If in bounded mode, output events to the current event file. Otherwise
// output events to the final log path.
if (IsBounded()) {
if (current_event_file_number_ == 0 ||
current_event_file_size_ >= max_event_file_size_) {
IncrementCurrentEventFile();
}
output_file = current_event_file_.get();
} else {
output_file = final_log_file_.get();
}
size_t bytes_written =
WriteToFile(output_file, *local_file_queue.front(), ",\n");
wrote_event_bytes_ |= bytes_written > 0;
// Keep track of the filesize for current event file when in bounded mode.
if (IsBounded())
current_event_file_size_ += bytes_written;
local_file_queue.pop();
}
}
void FileNetLogObserver::FileWriter::DeleteAllFiles() {
DCHECK(task_runner_->RunsTasksInCurrentSequence());
final_log_file_.reset();
if (IsBounded()) {
current_event_file_.reset();
base::DeleteFile(GetInprogressDirectory(), true);
}
base::DeleteFile(final_log_path_, false);
}
void FileNetLogObserver::FileWriter::FlushThenStop(
scoped_refptr<FileNetLogObserver::WriteQueue> write_queue,
std::unique_ptr<base::Value> polled_data) {
Flush(write_queue);
Stop(std::move(polled_data));
}
bool FileNetLogObserver::FileWriter::IsUnbounded() const {
return max_event_file_size_ == kNoLimit;
}
bool FileNetLogObserver::FileWriter::IsBounded() const {
return !IsUnbounded();
}
void FileNetLogObserver::FileWriter::IncrementCurrentEventFile() {
DCHECK(task_runner_->RunsTasksInCurrentSequence());
DCHECK(IsBounded());
current_event_file_number_++;
current_event_file_ = OpenFileForWrite(
GetEventFilePath(FileNumberToIndex(current_event_file_number_)));
current_event_file_size_ = 0;
}
base::FilePath FileNetLogObserver::FileWriter::GetInprogressDirectory() const {
return final_log_path_.AddExtension(FILE_PATH_LITERAL(".inprogress"));
}
base::FilePath FileNetLogObserver::FileWriter::GetEventFilePath(
size_t index) const {
DCHECK_LT(index, total_num_event_files_);
DCHECK(IsBounded());
return GetInprogressDirectory().AppendASCII(
"event_file_" + base::SizeTToString(index) + ".json");
}
base::FilePath FileNetLogObserver::FileWriter::GetConstantsFilePath() const {
return GetInprogressDirectory().AppendASCII("constants.json");
}
base::FilePath FileNetLogObserver::FileWriter::GetClosingFilePath() const {
return GetInprogressDirectory().AppendASCII("end_netlog.json");
}
size_t FileNetLogObserver::FileWriter::FileNumberToIndex(
size_t file_number) const {
DCHECK_GT(file_number, 0u);
// Note that "file numbers" start at 1 not 0.
return (file_number - 1) % total_num_event_files_;
}
void FileNetLogObserver::FileWriter::WriteConstantsToFile(
std::unique_ptr<base::Value> constants_value,
FILE* file) {
// Print constants to file and open events array.
std::string json;
// It should always be possible to convert constants to JSON.
if (!base::JSONWriter::Write(*constants_value, &json))
DCHECK(false);
WriteToFile(file, "{\"constants\":", json, ",\n\"events\": [\n");
}
void FileNetLogObserver::FileWriter::WritePolledDataToFile(
std::unique_ptr<base::Value> polled_data,
FILE* file) {
// Close the events array.
WriteToFile(file, "]");
// Write the polled data (if any).
if (polled_data) {
std::string polled_data_json;
base::JSONWriter::Write(*polled_data, &polled_data_json);
if (!polled_data_json.empty())
WriteToFile(file, ",\n\"polledData\": ", polled_data_json, "\n");
}
// Close the log.
WriteToFile(file, "}\n");
}
void FileNetLogObserver::FileWriter::RewindIfWroteEventBytes(FILE* file) const {
if (file && wrote_event_bytes_) {
// To be valid JSON the events array should not end with a comma. If events
// were written though, they will have been terminated with "\n," so strip
// it before closing the events array.
fseek(file, -2, SEEK_END);
}
}
void FileNetLogObserver::FileWriter::StitchFinalLogFile() {
// Make sure all the events files are flushed (as will read them next).
current_event_file_.reset();
// Allocate a 64K buffer used for reading the files. At most kReadBufferSize
// bytes will be in memory at a time.
const size_t kReadBufferSize = 1 << 16; // 64KiB
std::unique_ptr<char[]> read_buffer(new char[kReadBufferSize]);
// Re-open the final log file in order to truncate it.
final_log_file_ = OpenFileForWrite(final_log_path_);
// Append the constants file.
AppendToFileThenDelete(GetConstantsFilePath(), final_log_file_.get(),
read_buffer.get(), kReadBufferSize);
// Iterate over the events files, from oldest to most recent, and append them
// to the final destination. Note that "file numbers" start at 1 not 0.
size_t end_filenumber = current_event_file_number_ + 1;
size_t begin_filenumber = current_event_file_number_ <= total_num_event_files_
? 1
: end_filenumber - total_num_event_files_;
for (size_t filenumber = begin_filenumber; filenumber < end_filenumber;
++filenumber) {
AppendToFileThenDelete(GetEventFilePath(FileNumberToIndex(filenumber)),
final_log_file_.get(), read_buffer.get(),
kReadBufferSize);
}
// Account for the final event line ending in a ",\n". Strip it to form valid
// JSON.
RewindIfWroteEventBytes(final_log_file_.get());
// Append the polled data.
AppendToFileThenDelete(GetClosingFilePath(), final_log_file_.get(),
read_buffer.get(), kReadBufferSize);
// Delete the inprogress directory (and anything that may still be left inside
// it).
base::DeleteFile(GetInprogressDirectory(), true);
}
void FileNetLogObserver::FileWriter::CreateInprogressDirectory() const {
DCHECK(IsBounded());
// base::CreateDirectory() creates missing parent directories. Since the
// target directory is a sibling to |final_log_path_|, if that file couldn't
// be opened don't attempt to create the directory either.
if (!final_log_file_)
return;
if (!base::CreateDirectory(GetInprogressDirectory())) {
LOG(WARNING) << "Failed creating directory: "
<< GetInprogressDirectory().value();
return;
}
// It is OK if the path is wrong due to encoding - this is really just a
// convenience display for the user in understanding what the file means.
std::string in_progress_path = GetInprogressDirectory().AsUTF8Unsafe();
// Since |final_log_file_| will not be written to until the very end, leave
// some data in it explaining that the real data is currently in the
// .inprogress directory. This ordinarily won't be visible (overwritten when
// stopping) however if logging does not end gracefully the comments are
// useful for recovery.
WriteToFile(
final_log_file_.get(), "Logging is in progress writing data to:\n ",
in_progress_path,
"\n\n"
"That data will be stitched into a single file (this one) once logging\n"
"has stopped.\n"
"\n"
"If logging was interrupted, you can stitch a NetLog file out of the\n"
".inprogress directory manually using:\n"
"\n"
"https://chromium.googlesource.com/chromium/src/+/master/net/tools/"
"stitch_net_log_files.py\n");
fflush(final_log_file_.get());
}
} // namespace net