charm-neutron-openvswitch/hooks/charmhelpers/core/decorators.py
2015-01-26 09:42:44 +00:00

58 lines
1.7 KiB
Python

# Copyright 2014-2015 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
#
# Copyright 2014 Canonical Ltd.
#
# Authors:
# Edward Hope-Morley <opentastic@gmail.com>
#
import time
from charmhelpers.core.hookenv import (
log,
INFO,
)
def retry_on_exception(num_retries, base_delay=0, exc_type=Exception):
"""If the decorated function raises exception exc_type, allow num_retries
retry attempts before raise the exception.
"""
def _retry_on_exception_inner_1(f):
def _retry_on_exception_inner_2(*args, **kwargs):
retries = num_retries
multiplier = 1
while True:
try:
return f(*args, **kwargs)
except exc_type:
if not retries:
raise
delay = base_delay * multiplier
multiplier += 1
log("Retrying '%s' %d more times (delay=%s)" %
(f.__name__, retries, delay), level=INFO)
retries -= 1
if delay:
time.sleep(delay)
return _retry_on_exception_inner_2
return _retry_on_exception_inner_1