remoting/host/win/host_event_file_logger.cc

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "remoting/host/win/host_event_file_logger.h"

#include <string>
#include <utility>

#include "base/base_paths.h"
#include "base/check.h"
#include "base/containers/span.h"
#include "base/files/file_util.h"
#include "base/i18n/time_formatting.h"
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/path_service.h"
#include "base/strings/stringprintf.h"
#include "base/time/time.h"
#include "remoting/host/win/event_trace_data.h"

namespace remoting {

namespace {

constexpr wchar_t kLatestLogSymbolicLinkName[] = L"latest.log";

}  // namespace

HostEventFileLogger::HostEventFileLogger(base::File log_file)
    : log_file_(std::move(log_file)) {}

HostEventFileLogger::~HostEventFileLogger() = default;

std::unique_ptr<HostEventLogger> HostEventFileLogger::Create() {
  base::FilePath directory;
  bool result = base::PathService::Get(base::DIR_EXE, &directory);
  DCHECK(result);

  if (!base::DirectoryExists(directory)) {
    LOG(ERROR) << "PathService returned an invalid DIR_EXE directory: "
               << directory;
    return nullptr;
  }

  base::FilePath log_file_path =
      directory.AppendASCII(base::UnlocalizedTimeFormatWithPattern(
          base::Time::Now(),
          "'chrome_remote_desktop'_yyyyMMdd_HHmmss_SSS.'log'"));

  // Create the log_file and set the write mode to append.
  base::File log_file(log_file_path, base::File::Flags::FLAG_APPEND |
                                         base::File::Flags::FLAG_CREATE);

  if (!log_file.IsValid()) {
    LOG(ERROR) << "Failed to create the output log file at: " << log_file_path;
    return nullptr;
  }

  base::FilePath sym_link_path = directory.Append(kLatestLogSymbolicLinkName);
  // We don't need to check for existence first as DeleteFile() 'succeeds' if
  // the file doesn't exist.
  if (!base::DeleteFile(sym_link_path)) {
    PLOG(WARNING) << "Failed to delete symlink";
  }
  if (!::CreateSymbolicLink(sym_link_path.value().c_str(),
                            log_file_path.value().c_str(),
                            /*file*/ 0)) {
    PLOG(WARNING) << "Failed to create symbolic link for latest log file.";
  }

  return base::WrapUnique(new HostEventFileLogger(std::move(log_file)));
}

void HostEventFileLogger::LogEvent(const EventTraceData& data) {
  // Log format is:
  // [YYYYMMDD/HHMMSS.sss:pid:tid:severity:file_name(line)] <message>
  const std::string timestamp = base::UnlocalizedTimeFormatWithPattern(
      data.time_stamp, "yyyyMMdd/HHmmss.SSS");
  std::string message = base::StringPrintf(
      "[%s:%05d:%05d:%s:%s(%d)] %s", timestamp.c_str(), data.process_id,
      data.thread_id, EventTraceData::SeverityToString(data.severity).c_str(),
      data.file_name.c_str(), data.line, data.message.c_str());

  log_file_.WriteAtCurrentPosAndCheck(base::as_byte_span(message));
}

}  // namespace remoting