codekingpro/portable-devtools

1# Copyright 2023 Google LLC2#3# Licensed under the Apache License, Version 2.0 (the "License");4# you may not use this file except in compliance with the License.5# You may obtain a copy of the License at6#7#      http://www.apache.org/licenses/LICENSE-2.08#9# Unless required by applicable law or agreed to in writing, software10# distributed under the License is distributed on an "AS IS" BASIS,11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.12# See the License for the specific language governing permissions and13# limitations under the License.14 15import copy16import logging17import threading18 19import google.auth.exceptions as e20 21_LOGGER = logging.getLogger(__name__)22 23 24class RefreshThreadManager:25    """26    Organizes exactly one background job that refresh a token.27    """28 29    def __init__(self):30        """Initializes the manager."""31 32        self._worker = None33        self._lock = threading.Lock()  # protects access to worker threads.34 35    def start_refresh(self, cred, request):36        """Starts a refresh thread for the given credentials.37        The credentials are refreshed using the request parameter.38        request and cred MUST not be None39 40        Returns True if a background refresh was kicked off. False otherwise.41 42        Args:43            cred: A credentials object.44            request: A request object.45        Returns:46          bool47        """48        if cred is None or request is None:49            raise e.InvalidValue(50                "Unable to start refresh. cred and request must be valid and instantiated objects."51            )52 53        with self._lock:54            if self._worker is not None and self._worker._error_info is not None:55                return False56 57            if self._worker is None or not self._worker.is_alive():  # pragma: NO COVER58                self._worker = RefreshThread(cred=cred, request=copy.deepcopy(request))59                self._worker.start()60        return True61 62    def clear_error(self):63        """64      Removes any errors that were stored from previous background refreshes.65      """66        with self._lock:67            if self._worker:68                self._worker._error_info = None69 70    def __getstate__(self):71        """Pickle helper that serializes the _lock attribute."""72        state = self.__dict__.copy()73        state["_lock"] = None74        return state75 76    def __setstate__(self, state):77        """Pickle helper that deserializes the _lock attribute."""78        state["_lock"] = threading.Lock()79        self.__dict__.update(state)80 81 82class RefreshThread(threading.Thread):83    """84    Thread that refreshes credentials.85    """86 87    def __init__(self, cred, request, **kwargs):88        """Initializes the thread.89 90        Args:91            cred: A Credential object to refresh.92            request: A Request object used to perform a credential refresh.93            **kwargs: Additional keyword arguments.94        """95 96        super().__init__(**kwargs)97        self._cred = cred98        self._request = request99        self._error_info = None100 101    def run(self):102        """103        Perform the credential refresh.104        """105        try:106            self._cred.refresh(self._request)107        except Exception as err:  # pragma: NO COVER108            _LOGGER.error(f"Background refresh failed due to: {err}")109            self._error_info = err110