// 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.
#ifndef CHROME_BROWSER_CHROMEOS_DRIVE_FILE_WRITE_WATCHER_H_
#define CHROME_BROWSER_CHROMEOS_DRIVE_FILE_WRITE_WATCHER_H_
#include "base/callback_forward.h"
#include "base/memory/scoped_ptr.h"
#include "chrome/browser/chromeos/drive/file_system_util.h"
namespace base {
class FilePath;
} // 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 {
public:
FileWriteWatcher();
~FileWriteWatcher();
// 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. http://crbug.com/269424
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();
private:
class FileWriteWatcherImpl;
scoped_ptr<FileWriteWatcherImpl, util::DestroyHelper> watcher_impl_;
DISALLOW_COPY_AND_ASSIGN(FileWriteWatcher);
};
} // namespace internal
} // namespace drive
#endif // CHROME_BROWSER_CHROMEOS_DRIVE_FILE_WRITE_WATCHER_H_