def get_token_async()

in server/scripts/cloudstorage/rest_api.py [0:0]

• 16 lines of code
• 5 McCabe index (conditional complexity)

  def get_token_async(self, refresh=False):
    """Get an authentication token.

    The token is cached in memcache, keyed by the scopes argument.
    Uses a random token expiration headroom value generated in the constructor
    to eliminate a burst of GET_ACCESS_TOKEN API requests.

    Args:
      refresh: If True, ignore a cached token; default False.

    Yields:
      An authentication token. This token is guaranteed to be non-expired.
    """
    key = '%s,%s' % (self.service_account_id, ','.join(self.scopes))
    ts = yield _AE_TokenStorage_.get_by_id_async(
        key, use_cache=True, use_memcache=True,
        use_datastore=self.retry_params.save_access_token)
    if refresh or ts is None or ts.expires < (
        time.time() + self.expiration_headroom):
      token, expires_at = yield self.make_token_async(
          self.scopes, self.service_account_id)
      timeout = int(expires_at - time.time())
      ts = _AE_TokenStorage_(id=key, token=token, expires=expires_at)
      if timeout > 0:
        yield ts.put_async(memcache_timeout=timeout,
                           use_datastore=self.retry_params.save_access_token,
                           use_cache=True, use_memcache=True)
    raise ndb.Return(ts.token)