| # Copyright (c) 2012, Google, Inc. |
| # All rights reserved. |
| # |
| # Permission is hereby granted, free of charge, to any person obtaining a |
| # copy of this software and associated documentation files (the |
| # "Software"), to deal in the Software without restriction, including |
| # without limitation the rights to use, copy, modify, merge, publish, dis- |
| # tribute, sublicense, and/or sell copies of the Software, and to permit |
| # persons to whom the Software is furnished to do so, subject to the fol- |
| # lowing conditions: |
| # |
| # The above copyright notice and this permission notice shall be included |
| # in all copies or substantial portions of the Software. |
| # |
| # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL- |
| # ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT |
| # SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
| # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| # IN THE SOFTWARE. |
| |
| import time |
| |
| from boto.provider import Provider |
| |
| |
| _HAS_GOOGLE_CREDENTIALS = None |
| |
| |
| def has_google_credentials(): |
| global _HAS_GOOGLE_CREDENTIALS |
| if _HAS_GOOGLE_CREDENTIALS is None: |
| provider = Provider('google') |
| if (provider.get_access_key() is None or |
| provider.get_secret_key() is None): |
| _HAS_GOOGLE_CREDENTIALS = False |
| else: |
| _HAS_GOOGLE_CREDENTIALS = True |
| return _HAS_GOOGLE_CREDENTIALS |
| |
| |
| def retry(ExceptionToCheck, tries=4, delay=3, backoff=2, logger=None): |
| """Retry calling the decorated function using an exponential backoff. |
| |
| Taken from: |
| https://github.com/saltycrane/retry-decorator |
| Licensed under BSD: |
| https://github.com/saltycrane/retry-decorator/blob/master/LICENSE |
| |
| :param ExceptionToCheck: the exception to check. may be a tuple of |
| exceptions to check |
| :type ExceptionToCheck: Exception or tuple |
| :param tries: number of times to try (not retry) before giving up |
| :type tries: int |
| :param delay: initial delay between retries in seconds |
| :type delay: int |
| :param backoff: backoff multiplier e.g. value of 2 will double the delay |
| each retry |
| :type backoff: int |
| :param logger: logger to use. If None, print |
| :type logger: logging.Logger instance |
| """ |
| def deco_retry(f): |
| def f_retry(*args, **kwargs): |
| mtries, mdelay = tries, delay |
| try_one_last_time = True |
| while mtries > 1: |
| try: |
| return f(*args, **kwargs) |
| try_one_last_time = False |
| break |
| except ExceptionToCheck, e: |
| msg = "%s, Retrying in %d seconds..." % (str(e), mdelay) |
| if logger: |
| logger.warning(msg) |
| else: |
| print msg |
| time.sleep(mdelay) |
| mtries -= 1 |
| mdelay *= backoff |
| if try_one_last_time: |
| return f(*args, **kwargs) |
| return |
| return f_retry # true decorator |
| return deco_retry |