charm-keystone/charmhelpers/core/decorators.py
James Page 960f1cec05 Resync charmhelpers for licensing change
The charm-helpers project have re-licensed to Apache 2.0
inline with the agreed licensing approach to intefaces,
layers and charms generally.

Resync helpers to bring charmhelpers inline with charm
codebase.

Change-Id: Icedfb79814e186290a3120d953c9077e4e4504fe
2016-07-06 16:35:04 +01:00

56 lines
1.7 KiB
Python

# Copyright 2014-2015 Canonical Limited.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# 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