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// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef STORAGE_BROWSER_FILE_SYSTEM_WATCHER_MANAGER_H_
#define STORAGE_BROWSER_FILE_SYSTEM_WATCHER_MANAGER_H_
#include "base/files/file.h"
#include "base/functional/callback_forward.h"
namespace storage {
class FileSystemURL;
// An interface for providing entry observing capability for file system
// backends.
//
// All member functions must be called on the IO thread. Callbacks will be
// called on the IO thread.
//
// It is NOT valid to give null callback to this class, and implementors
// can assume that they don't get any null callbacks.
class WatcherManager {
public:
enum ChangeType { CHANGED, DELETED };
using StatusCallback = base::OnceCallback<void(base::File::Error result)>;
using NotificationCallback =
base::RepeatingCallback<void(ChangeType change_type)>;
WatcherManager(const WatcherManager&) = delete;
WatcherManager& operator=(const WatcherManager&) = delete;
virtual ~WatcherManager() = default;
// Adds an entry watcher. If the |recursive| mode is not supported then
// FILE_ERROR_INVALID_OPERATION must be returned as an error. If the |url| is
// already watched with the same |recursive|, or setting up the watcher fails,
// then |callback| must be called with a specific error code.
//
// There may be up to two watchers for the same |url| as well as one of them
// is recursive, and the other one is not.
//
// In case of a success |callback| must be called with the FILE_OK error code.
// |notification_callback| is called for every change related to the watched
// directory.
virtual void AddWatcher(const FileSystemURL& url,
bool recursive,
StatusCallback callback,
NotificationCallback notification_callback) = 0;
// Removes a watcher represented by |url| in |recursive| mode.
virtual void RemoveWatcher(const FileSystemURL& url,
bool recursive,
StatusCallback callback) = 0;
protected:
WatcherManager() = default;
};
} // namespace storage
#endif // STORAGE_BROWSER_FILE_SYSTEM_WATCHER_MANAGER_H_
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