Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/retrying.py: 60%
Shortcuts on this page
r m x toggle line displays
j k next/prev highlighted chunk
0 (zero) top of page
1 (one) first highlighted chunk
1# Copyright 2013-2014 Ray Holder
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7# http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14import logging
15import random
16import sys
17import time
18import traceback
19from functools import wraps
21# sys.maxint / 2, since Python 3.2 doesn't have a sys.maxint...
22MAX_WAIT = 1073741823
25def _retry_if_exception_of_type(retryable_types):
26 def _retry_if_exception_these_types(exception):
27 return isinstance(exception, retryable_types)
29 return _retry_if_exception_these_types
32def retry(*dargs, **dkw):
33 """
34 Decorator function that instantiates the Retrying object
35 @param *dargs: positional arguments passed to Retrying object
36 @param **dkw: keyword arguments passed to the Retrying object
37 """
38 # support both @retry and @retry() as valid syntax
39 if len(dargs) == 1 and callable(dargs[0]):
41 def wrap_simple(f):
42 @wraps(f)
43 def wrapped_f(*args, **kw):
44 return Retrying().call(f, *args, **kw)
46 return wrapped_f
48 return wrap_simple(dargs[0])
50 else:
52 def wrap(f):
53 @wraps(f)
54 def wrapped_f(*args, **kw):
55 return Retrying(*dargs, **dkw).call(f, *args, **kw)
57 return wrapped_f
59 return wrap
61_default_logger = None
62_configured_null_logger = False
64def _pick_logger(logger=None):
65 # Factor this logic out into a smaller function so that `global` only needs to be here,
66 # not the large __init__ function.
67 global _default_logger, _configured_null_logger
69 if logger in (True, None):
70 if _default_logger is None:
71 _default_logger = logging.getLogger(__name__)
72 # Only add the null handler once, not every time we get the logger
73 if logger is None and not _configured_null_logger:
74 _configured_null_logger = True
75 _default_logger.addHandler(logging.NullHandler())
76 _default_logger.propagate = False
77 return _default_logger
78 else: # Not None (and not True) -> must have supplied a logger. Just use that.
79 return logger
82class Retrying(object):
83 def __init__(
84 self,
85 stop=None,
86 wait=None,
87 stop_max_attempt_number=None,
88 stop_max_delay=None,
89 wait_fixed=None,
90 wait_random_min=None,
91 wait_random_max=None,
92 wait_incrementing_start=None,
93 wait_incrementing_increment=None,
94 wait_incrementing_max=None,
95 wait_exponential_multiplier=None,
96 wait_exponential_max=None,
97 retry_on_exception=None,
98 retry_on_result=None,
99 wrap_exception=False,
100 stop_func=None,
101 wait_func=None,
102 wait_jitter_max=None,
103 before_attempts=None,
104 after_attempts=None,
105 logger=None,
106 ):
108 self._stop_max_attempt_number = (
109 5 if stop_max_attempt_number is None else stop_max_attempt_number
110 )
111 self._stop_max_delay = 100 if stop_max_delay is None else stop_max_delay
112 self._wait_fixed = 1000 if wait_fixed is None else wait_fixed
113 self._wait_random_min = 0 if wait_random_min is None else wait_random_min
114 self._wait_random_max = 1000 if wait_random_max is None else wait_random_max
115 self._wait_incrementing_start = (
116 0 if wait_incrementing_start is None else wait_incrementing_start
117 )
118 self._wait_incrementing_increment = (
119 100 if wait_incrementing_increment is None else wait_incrementing_increment
120 )
121 self._wait_exponential_multiplier = (
122 1 if wait_exponential_multiplier is None else wait_exponential_multiplier
123 )
124 self._wait_exponential_max = (
125 MAX_WAIT if wait_exponential_max is None else wait_exponential_max
126 )
127 self._wait_incrementing_max = (
128 MAX_WAIT if wait_incrementing_max is None else wait_incrementing_max
129 )
130 self._wait_jitter_max = 0 if wait_jitter_max is None else wait_jitter_max
131 self._before_attempts = before_attempts
132 self._after_attempts = after_attempts
134 self._logger = _pick_logger(logger)
136 # TODO add chaining of stop behaviors
137 # stop behavior
138 stop_funcs = []
139 if stop_max_attempt_number is not None:
140 stop_funcs.append(self.stop_after_attempt)
142 if stop_max_delay is not None:
143 stop_funcs.append(self.stop_after_delay)
145 if stop_func is not None:
146 self.stop = stop_func
148 elif stop is None:
149 self.stop = lambda attempts, delay: any(
150 f(attempts, delay) for f in stop_funcs
151 )
153 else:
154 self.stop = getattr(self, stop)
156 # TODO add chaining of wait behaviors
157 # wait behavior
158 wait_funcs = [lambda *args, **kwargs: 0]
159 if wait_fixed is not None:
160 wait_funcs.append(self.fixed_sleep)
162 if wait_random_min is not None or wait_random_max is not None:
163 wait_funcs.append(self.random_sleep)
165 if (
166 wait_incrementing_start is not None
167 or wait_incrementing_increment is not None
168 ):
169 wait_funcs.append(self.incrementing_sleep)
171 if wait_exponential_multiplier is not None or wait_exponential_max is not None:
172 wait_funcs.append(self.exponential_sleep)
174 if wait_func is not None:
175 self.wait = wait_func
177 elif wait is None:
178 self.wait = lambda attempts, delay: max(
179 f(attempts, delay) for f in wait_funcs
180 )
182 else:
183 self.wait = getattr(self, wait)
185 # retry on exception filter
186 if retry_on_exception is None:
187 self._retry_on_exception = self.always_reject
188 else:
189 # this allows for providing a tuple of exception types that
190 # should be allowed to retry on, and avoids having to create
191 # a callback that does the same thing
192 if isinstance(retry_on_exception, (tuple, Exception)):
193 retry_on_exception = _retry_if_exception_of_type(retry_on_exception)
194 self._retry_on_exception = retry_on_exception
196 # retry on result filter
197 if retry_on_result is None:
198 self._retry_on_result = self.never_reject
199 else:
200 self._retry_on_result = retry_on_result
202 self._wrap_exception = wrap_exception
204 def stop_after_attempt(self, previous_attempt_number, delay_since_first_attempt_ms):
205 """Stop after the previous attempt >= stop_max_attempt_number."""
206 return previous_attempt_number >= self._stop_max_attempt_number
208 def stop_after_delay(self, previous_attempt_number, delay_since_first_attempt_ms):
209 """Stop after the time from the first attempt >= stop_max_delay."""
210 return delay_since_first_attempt_ms >= self._stop_max_delay
212 @staticmethod
213 def no_sleep(previous_attempt_number, delay_since_first_attempt_ms):
214 """Don't sleep at all before retrying."""
215 return 0
217 def fixed_sleep(self, previous_attempt_number, delay_since_first_attempt_ms):
218 """Sleep a fixed amount of time between each retry."""
219 return self._wait_fixed
221 def random_sleep(self, previous_attempt_number, delay_since_first_attempt_ms):
222 """Sleep a random amount of time between wait_random_min and wait_random_max"""
223 return random.randint(self._wait_random_min, self._wait_random_max)
225 def incrementing_sleep(self, previous_attempt_number, delay_since_first_attempt_ms):
226 """
227 Sleep an incremental amount of time after each attempt, starting at
228 wait_incrementing_start and incrementing by wait_incrementing_increment
229 """
230 result = self._wait_incrementing_start + (
231 self._wait_incrementing_increment * (previous_attempt_number - 1)
232 )
233 if result > self._wait_incrementing_max:
234 result = self._wait_incrementing_max
235 if result < 0:
236 result = 0
237 return result
239 def exponential_sleep(self, previous_attempt_number, delay_since_first_attempt_ms):
240 exp = 2**previous_attempt_number
241 result = self._wait_exponential_multiplier * exp
242 if result > self._wait_exponential_max:
243 result = self._wait_exponential_max
244 if result < 0:
245 result = 0
246 return result
248 @staticmethod
249 def never_reject(result):
250 return False
252 @staticmethod
253 def always_reject(result):
254 return True
256 def should_reject(self, attempt):
257 reject = False
258 if attempt.has_exception:
259 reject |= self._retry_on_exception(attempt.value[1])
260 else:
261 reject |= self._retry_on_result(attempt.value)
263 return reject
265 def call(self, fn, *args, **kwargs):
266 start_time = int(round(time.time() * 1000))
267 attempt_number = 1
268 while True:
269 if self._before_attempts:
270 self._before_attempts(attempt_number)
272 try:
273 attempt = Attempt(fn(*args, **kwargs), attempt_number, False)
274 except Exception:
275 tb = sys.exc_info()
276 attempt = Attempt(tb, attempt_number, True)
278 if not self.should_reject(attempt):
279 return attempt.get(self._wrap_exception)
281 self._logger.warning(attempt)
282 if self._after_attempts:
283 self._after_attempts(attempt_number)
285 delay_since_first_attempt_ms = int(round(time.time() * 1000)) - start_time
286 if self.stop(attempt_number, delay_since_first_attempt_ms):
287 if not self._wrap_exception and attempt.has_exception:
288 # get() on an attempt with an exception should cause it to be raised, but raise just in case
289 raise attempt.get()
290 else:
291 raise RetryError(attempt)
292 else:
293 sleep = self.wait(attempt_number, delay_since_first_attempt_ms)
294 if self._wait_jitter_max:
295 jitter = random.random() * self._wait_jitter_max
296 sleep = sleep + max(0, jitter)
297 self._logger.info(f"Retrying in {sleep / 1000.0:.2f} seconds.")
298 time.sleep(sleep / 1000.0)
300 attempt_number += 1
303class Attempt(object):
304 """
305 An Attempt encapsulates a call to a target function that may end as a
306 normal return value from the function or an Exception depending on what
307 occurred during the execution.
308 """
310 def __init__(self, value, attempt_number, has_exception):
311 self.value = value
312 self.attempt_number = attempt_number
313 self.has_exception = has_exception
315 def get(self, wrap_exception=False):
316 """
317 Return the return value of this Attempt instance or raise an Exception.
318 If wrap_exception is true, this Attempt is wrapped inside of a
319 RetryError before being raised.
320 """
321 if self.has_exception:
322 if wrap_exception:
323 raise RetryError(self)
324 else:
325 exc_type, exc, tb = self.value
326 raise exc.with_traceback(tb)
327 else:
328 return self.value
330 def __repr__(self):
331 if self.has_exception:
332 return f"Attempts: {self.attempt_number}, Error:\n{''.join(traceback.format_tb(self.value[2]))}"
333 else:
334 return f"Attempts: {self.attempt_number}, Value: {self.value}"
337class RetryError(Exception):
338 """
339 A RetryError encapsulates the last Attempt instance right before giving up.
340 """
342 def __init__(self, last_attempt):
343 self.last_attempt = last_attempt
345 def __str__(self):
346 return f"RetryError[{self.last_attempt}]"