/usr/lib/python2.7/dist-packages/fasteners/_utils.py is in python-fasteners 0.12.0-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 | # -*- coding: utf-8 -*-
# Copyright (C) 2015 Yahoo! Inc. All Rights Reserved.
#
# All Rights Reserved.
#
# 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.
import logging
import time
from monotonic import monotonic as now # noqa
# log level for low-level debugging
BLATHER = 5
LOG = logging.getLogger(__name__)
class LockStack(object):
"""Simple lock stack to get and release many locks.
An instance of this should **not** be used by many threads at the
same time, as the stack that is maintained will be corrupted and
invalid if that is attempted.
"""
def __init__(self):
self._stack = []
def acquire_lock(self, lock):
gotten = lock.acquire()
if gotten:
self._stack.append(lock)
return gotten
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, exc_tb):
am_left = len(self._stack)
tot_am = am_left
while self._stack:
lock = self._stack.pop()
try:
lock.release()
except Exception:
LOG.exception("Failed releasing lock %s from lock"
" stack with %s locks", am_left, tot_am)
am_left -= 1
class RetryAgain(Exception):
"""Exception to signal to retry helper to try again."""
class Retry(object):
"""A little retry helper object."""
def __init__(self, delay, max_delay,
sleep_func=time.sleep, watch=None):
self.delay = delay
self.attempts = 0
self.max_delay = max_delay
self.sleep_func = sleep_func
self.watch = watch
def __call__(self, fn, *args, **kwargs):
while True:
self.attempts += 1
try:
return fn(*args, **kwargs)
except RetryAgain:
maybe_delay = self.attempts * self.delay
if maybe_delay < self.max_delay:
actual_delay = maybe_delay
else:
actual_delay = self.max_delay
actual_delay = max(0.0, actual_delay)
if self.watch is not None:
leftover = self.watch.leftover()
if leftover is not None and leftover < actual_delay:
actual_delay = leftover
self.sleep_func(actual_delay)
class StopWatch(object):
"""A really basic stop watch."""
def __init__(self, duration=None):
self.duration = duration
self.started_at = None
self.stopped_at = None
def leftover(self):
if self.duration is None:
return None
return max(0.0, self.duration - self.elapsed())
def elapsed(self):
if self.stopped_at is not None:
end_time = self.stopped_at
else:
end_time = now()
return max(0.0, end_time - self.started_at)
def __enter__(self):
self.start()
return self
def __exit__(self, exc_type, exc_value, exc_tb):
self.stopped_at = now()
def start(self):
self.started_at = now()
self.stopped_at = None
def expired(self):
if self.duration is None:
return False
else:
return self.elapsed() > self.duration
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