deb-heat/heat/common/timeutils.py
Ethan Lynn 11c1b62052 Remove deprecated function i18n.install('heat')
Since i18n.install() is deprecated, remove it from heat codes and
import i18n._() to where it needed.

blueprint oslo-i18n
Change-Id: Icefada18b5a33112b425cd90d31d3a6a5f06188a
2014-10-13 10:31:28 +08:00

63 lines
1.9 KiB
Python

#
# 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.
"""
Utilities for handling ISO 8601 duration format.
"""
import random
import re
from heat.common.i18n import _
iso_duration_re = re.compile('PT(?:(\d+)H)?(?:(\d+)M)?(?:(\d+)S)?$')
def parse_isoduration(duration):
"""
Convert duration in ISO 8601 format to second(s).
Year, Month, Week, and Day designators are not supported.
Example: 'PT12H30M5S'
"""
result = iso_duration_re.match(duration)
if not result:
raise ValueError(_('Only ISO 8601 duration format of the form '
'PT#H#M#S is supported.'))
t = 0
t += (3600 * int(result.group(1))) if result.group(1) else 0
t += (60 * int(result.group(2))) if result.group(2) else 0
t += int(result.group(3)) if result.group(3) else 0
return t
def retry_backoff_delay(attempt, scale_factor=1.0, jitter_max=0.0):
"""
Calculate an exponential backoff delay with jitter.
Delay is calculated as
2^attempt + (uniform random from [0,1) * jitter_max)
:param attempt: The count of the current retry attempt
:param scale_factor: Multiplier to scale the exponential delay by
:param jitter_max: Maximum of random seconds to add to the delay
:returns: Seconds since epoch to wait until
"""
exp = float(2 ** attempt) * float(scale_factor)
if jitter_max == 0.0:
return exp
return exp + random.random() * jitter_max