xref: /aosp_15_r20/external/cronet/net/dns/notify_watcher_mac.h (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_DNS_NOTIFY_WATCHER_MAC_H_
#define NET_DNS_NOTIFY_WATCHER_MAC_H_

#include <memory>

#include "base/files/file_descriptor_watcher_posix.h"
#include "base/functional/callback.h"

namespace net {

// Watches for notifications from Libnotify and delivers them to a Callback.
// After failure the watch is cancelled and will have to be restarted.
class NotifyWatcherMac {
 public:
  // Called on received notification with true on success and false on error.
  typedef base::RepeatingCallback<void(bool succeeded)> CallbackType;

  NotifyWatcherMac();

  NotifyWatcherMac(const NotifyWatcherMac&) = delete;
  NotifyWatcherMac& operator=(const NotifyWatcherMac&) = delete;

  // When deleted, automatically cancels.
  virtual ~NotifyWatcherMac();

  // Registers for notifications for |key|. Returns true if succeeds. If so,
  // will deliver asynchronous notifications and errors to |callback|.
  bool Watch(const char* key, const CallbackType& callback);

  // Cancels the watch.
  void Cancel();

 private:
  // Called by |watcher_| when |notify_fd_| can be read without blocking.
  void OnFileCanReadWithoutBlocking();

  CallbackType CancelInternal();

  int notify_fd_;
  int notify_token_;
  CallbackType callback_;
  std::unique_ptr<base::FileDescriptorWatcher::Controller> watcher_;
};

}  // namespace net

#endif  // NET_DNS_NOTIFY_WATCHER_MAC_H_