Revert 274735 "Use FSEvents for recursive file watch on Mac"

trunk/src/base/files/file_path_watcher_kqueue.h

-// Copyright 2014 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 BASE_FILES_FILE_PATH_WATCHER_KQUEUE_H_
-#define BASE_FILES_FILE_PATH_WATCHER_KQUEUE_H_
-
-#include <sys/event.h>
-#include <vector>
-
-#include "base/files/file_path.h"
-#include "base/files/file_path_watcher.h"
-#include "base/message_loop/message_loop.h"
-#include "base/message_loop/message_loop_proxy.h"
-
-namespace base {
-
-// Mac-specific file watcher implementation based on kqueue.
-// The Linux and Windows versions are able to detect:
-// - file creation/deletion/modification in a watched directory
-// - file creation/deletion/modification for a watched file
-// - modifications to the paths to a watched object that would affect the
-//   object such as renaming/attibute changes etc.
-// The kqueue implementation will handle all of the items in the list above
-// except for detecting modifications to files in a watched directory. It will
-// detect the creation and deletion of files, just not the modification of
-// files. It does however detect the attribute changes that the FSEvents impl
-// would miss.
-class FilePathWatcherKQueue : public FilePathWatcher::PlatformDelegate,
-                              public MessageLoopForIO::Watcher,
-                              public MessageLoop::DestructionObserver {
- public:
-  FilePathWatcherKQueue();
-
-  // MessageLoopForIO::Watcher overrides.
-  virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
-  virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE;
-
-  // MessageLoop::DestructionObserver overrides.
-  virtual void WillDestroyCurrentMessageLoop() OVERRIDE;
-
-  // FilePathWatcher::PlatformDelegate overrides.
-  virtual bool Watch(const FilePath& path,
-                     bool recursive,
-                     const FilePathWatcher::Callback& callback) OVERRIDE;
-  virtual void Cancel() OVERRIDE;
-
- protected:
-  virtual ~FilePathWatcherKQueue();
-
- private:
-  class EventData {
-   public:
-    EventData(const FilePath& path, const FilePath::StringType& subdir)
-        : path_(path), subdir_(subdir) { }
-    FilePath path_;  // Full path to this item.
-    FilePath::StringType subdir_;  // Path to any sub item.
-  };
-
-  typedef std::vector<struct kevent> EventVector;
-
-  // Can only be called on |io_message_loop_|'s thread.
-  virtual void CancelOnMessageLoopThread() OVERRIDE;
-
-  // Returns true if the kevent values are error free.
-  bool AreKeventValuesValid(struct kevent* kevents, int count);
-
-  // Respond to a change of attributes of the path component represented by
-  // |event|. Sets |target_file_affected| to true if |target_| is affected.
-  // Sets |update_watches| to true if |events_| need to be updated.
-  void HandleAttributesChange(const EventVector::iterator& event,
-                              bool* target_file_affected,
-                              bool* update_watches);
-
-  // Respond to a move or deletion of the path component represented by
-  // |event|. Sets |target_file_affected| to true if |target_| is affected.
-  // Sets |update_watches| to true if |events_| need to be updated.
-  void HandleDeleteOrMoveChange(const EventVector::iterator& event,
-                                bool* target_file_affected,
-                                bool* update_watches);
-
-  // Respond to a creation of an item in the path component represented by
-  // |event|. Sets |target_file_affected| to true if |target_| is affected.
-  // Sets |update_watches| to true if |events_| need to be updated.
-  void HandleCreateItemChange(const EventVector::iterator& event,
-                              bool* target_file_affected,
-                              bool* update_watches);
-
-  // Update |events_| with the current status of the system.
-  // Sets |target_file_affected| to true if |target_| is affected.
-  // Returns false if an error occurs.
-  bool UpdateWatches(bool* target_file_affected);
-
-  // Fills |events| with one kevent per component in |path|.
-  // Returns the number of valid events created where a valid event is
-  // defined as one that has a ident (file descriptor) field != -1.
-  static int EventsForPath(FilePath path, EventVector *events);
-
-  // Release a kevent generated by EventsForPath.
-  static void ReleaseEvent(struct kevent& event);
-
-  // Returns a file descriptor that will not block the system from deleting
-  // the file it references.
-  static uintptr_t FileDescriptorForPath(const FilePath& path);
-
-  static const uintptr_t kNoFileDescriptor = static_cast<uintptr_t>(-1);
-
-  // Closes |*fd| and sets |*fd| to -1.
-  static void CloseFileDescriptor(uintptr_t* fd);
-
-  // Returns true if kevent has open file descriptor.
-  static bool IsKeventFileDescriptorOpen(const struct kevent& event) {
-    return event.ident != kNoFileDescriptor;
-  }
-
-  static EventData* EventDataForKevent(const struct kevent& event) {
-    return reinterpret_cast<EventData*>(event.udata);
-  }
-
-  EventVector events_;
-  scoped_refptr<base::MessageLoopProxy> io_message_loop_;
-  MessageLoopForIO::FileDescriptorWatcher kqueue_watcher_;
-  FilePathWatcher::Callback callback_;
-  FilePath target_;
-  int kqueue_;
-
-  DISALLOW_COPY_AND_ASSIGN(FilePathWatcherKQueue);
-};
-
-}  // namespace base
-
-#endif  // BASE_FILES_FILE_PATH_WATCHER_KQUEUE_H_