"""
SoftLayer.decoration
~~~~~~~~~~~~~~~~~~~~
Handy decorators to use
:license: MIT, see LICENSE for more details.
"""
from functools import wraps
from random import randint
from time import sleep
from SoftLayer import exceptions
RETRIABLE = (
exceptions.ServerError,
exceptions.ApplicationError,
exceptions.RemoteSystemError,
)
[docs]
def retry(ex=RETRIABLE, tries=4, delay=5, backoff=2, logger=None):
"""Retry calling the decorated function using an exponential backoff.
http://www.saltycrane.com/blog/2009/11/trying-out-retry-decorator-python/
original from: http://wiki.python.org/moin/PythonDecoratorLibrary#Retry
:param ex: the exception to check. may be a tuple of exceptions to check
:param tries: number of times to try (not retry) before giving up
:param delay: initial delay between retries in seconds.
A random 0-5s will be added to this number to stagger calls.
:param backoff: backoff multiplier e.g. value of 2 will double the delay each retry
:param logger: logger to use. If None, print
"""
def deco_retry(func):
"""@retry(arg[, ...]) -> true decorator"""
@wraps(func)
def f_retry(*args, **kwargs):
"""true decorator -> decorated function"""
mtries, mdelay = tries, delay
while mtries > 1:
try:
return func(*args, **kwargs)
except ex as error:
sleeping = mdelay + randint(0, 5)
msg = "%s, Retrying in %d seconds..." % (str(error), sleeping)
if logger:
logger.warning(msg)
sleep(sleeping)
mtries -= 1
mdelay *= backoff
return func(*args, **kwargs)
return f_retry # true decorator
return deco_retry