1// Copyright 2014 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef BASE_FILES_FILE_PATH_WATCHER_FSEVENTS_H_ 6#define BASE_FILES_FILE_PATH_WATCHER_FSEVENTS_H_ 7 8#include <CoreServices/CoreServices.h> 9 10#include <vector> 11 12#include "base/files/file_path.h" 13#include "base/files/file_path_watcher.h" 14 15namespace base { 16 17// Mac-specific file watcher implementation based on FSEvents. 18// There are trade-offs between the FSEvents implementation and a kqueue 19// implementation. The biggest issues are that FSEvents on 10.6 sometimes drops 20// events and kqueue does not trigger for modifications to a file in a watched 21// directory. See file_path_watcher_mac.cc for the code that decides when to 22// use which one. 23class FilePathWatcherFSEvents : public FilePathWatcher::PlatformDelegate { 24 public: 25 FilePathWatcherFSEvents(); 26 27 // Called from the FSEvents callback whenever there is a change to the paths. 28 void OnFilePathsChanged(const std::vector<FilePath>& paths); 29 30 // (Re-)Initialize the event stream to start reporting events from 31 // |start_event|. 32 void UpdateEventStream(FSEventStreamEventId start_event); 33 34 // Returns true if resolving the target path got a different result than 35 // last time it was done. 36 bool ResolveTargetPath(); 37 38 // FilePathWatcher::PlatformDelegate overrides. 39 virtual bool Watch(const FilePath& path, 40 bool recursive, 41 const FilePathWatcher::Callback& callback) OVERRIDE; 42 virtual void Cancel() OVERRIDE; 43 44 private: 45 virtual ~FilePathWatcherFSEvents(); 46 47 // Destroy the event stream. 48 void DestroyEventStream(); 49 50 // Start watching the FSEventStream. 51 void StartEventStream(FSEventStreamEventId start_event); 52 53 // Cleans up and stops the event stream. 54 virtual void CancelOnMessageLoopThread() OVERRIDE; 55 56 // Callback to notify upon changes. 57 FilePathWatcher::Callback callback_; 58 59 // Target path to watch (passed to callback). 60 FilePath target_; 61 62 // Target path with all symbolic links resolved. 63 FilePath resolved_target_; 64 65 // Backend stream we receive event callbacks from (strong reference). 66 FSEventStreamRef fsevent_stream_; 67 68 DISALLOW_COPY_AND_ASSIGN(FilePathWatcherFSEvents); 69}; 70 71} // namespace base 72 73#endif // BASE_FILES_FILE_PATH_WATCHER_FSEVENTS_H_ 74