blob: 1b3a5c7968af1bda488ec68e2f7a9b9b634ba76d [file] [log] [blame]
// Copyright 2013 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 <memory>
#include "base/callback_forward.h"
#include "base/macros.h"
#include "base/threading/thread_checker.h"
#include "components/drive/file_system_core_util.h"
namespace base {
class FilePath;
class SequencedTaskRunner;
} // namespace base
namespace drive {
namespace internal {
typedef base::Callback<void(bool)> StartWatchCallback;
// The class watches modification to Drive files in the cache directory.
// This is used for returning a local writable snapshot of Drive files from the
// Save-As file dialog, so that the callers of the dialog can save to Drive
// without any special handling about Drive.
class FileWriteWatcher {
explicit FileWriteWatcher(base::SequencedTaskRunner* blocking_task_runner);
// Starts watching the modification to |path|. When it successfully started
// watching, it runs |on_start_callback| by passing true as the argument.
// Or if it failed, the callback is run with false.
// Detected modification is notified by calling |on_write_callback|.
// Currently, the modification is watched in "one-shot" manner. That is, once
// a modification is notified, the watch is deactivated for freeing system
// resources. As a heuristic to capture the real end of write operations that
// might be done by several chunked writes, the notification is fired after
// 5 seconds has passed after the last write operation is detected.
// TODO(kinaba): investigate the possibility to continuously watch the whole
// cache directory.
void StartWatch(const base::FilePath& path,
const StartWatchCallback& on_start_callback,
const base::Closure& on_write_callback);
// For testing purpose, stops inserting delay between the write detection and
// notification to the |on_write_callback|.
void DisableDelayForTesting();
class FileWriteWatcherImpl;
std::unique_ptr<FileWriteWatcherImpl, util::DestroyHelper> watcher_impl_;
base::ThreadChecker thread_checker_;
} // namespace internal
} // namespace drive