bazarr/libs/retry/api.py

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2018-11-01 00:08:29 +08:00
import logging
import random
import time
from functools import partial
from retry.compat import decorator
logging_logger = logging.getLogger(__name__)
def __retry_internal(f, exceptions=Exception, tries=-1, delay=0, max_delay=None, backoff=1, jitter=0,
logger=logging_logger):
"""
Executes a function and retries it if it failed.
:param f: the function to execute.
:param exceptions: an exception or a tuple of exceptions to catch. default: Exception.
:param tries: the maximum number of attempts. default: -1 (infinite).
:param delay: initial delay between attempts. default: 0.
:param max_delay: the maximum value of delay. default: None (no limit).
:param backoff: multiplier applied to delay between attempts. default: 1 (no backoff).
:param jitter: extra seconds added to delay between attempts. default: 0.
fixed if a number, random if a range tuple (min, max)
:param logger: logger.warning(fmt, error, delay) will be called on failed attempts.
default: retry.logging_logger. if None, logging is disabled.
:returns: the result of the f function.
"""
_tries, _delay = tries, delay
while _tries:
try:
return f()
except exceptions as e:
_tries -= 1
if not _tries:
raise
if logger is not None:
logger.warning('%s, retrying in %s seconds...', e, _delay)
time.sleep(_delay)
_delay *= backoff
if isinstance(jitter, tuple):
_delay += random.uniform(*jitter)
else:
_delay += jitter
if max_delay is not None:
_delay = min(_delay, max_delay)
def retry(exceptions=Exception, tries=-1, delay=0, max_delay=None, backoff=1, jitter=0, logger=logging_logger):
"""Returns a retry decorator.
:param exceptions: an exception or a tuple of exceptions to catch. default: Exception.
:param tries: the maximum number of attempts. default: -1 (infinite).
:param delay: initial delay between attempts. default: 0.
:param max_delay: the maximum value of delay. default: None (no limit).
:param backoff: multiplier applied to delay between attempts. default: 1 (no backoff).
:param jitter: extra seconds added to delay between attempts. default: 0.
fixed if a number, random if a range tuple (min, max)
:param logger: logger.warning(fmt, error, delay) will be called on failed attempts.
default: retry.logging_logger. if None, logging is disabled.
:returns: a retry decorator.
"""
@decorator
def retry_decorator(f, *fargs, **fkwargs):
args = fargs if fargs else list()
kwargs = fkwargs if fkwargs else dict()
return __retry_internal(partial(f, *args, **kwargs), exceptions, tries, delay, max_delay, backoff, jitter,
logger)
return retry_decorator
def retry_call(f, fargs=None, fkwargs=None, exceptions=Exception, tries=-1, delay=0, max_delay=None, backoff=1,
jitter=0,
logger=logging_logger):
"""
Calls a function and re-executes it if it failed.
:param f: the function to execute.
:param fargs: the positional arguments of the function to execute.
:param fkwargs: the named arguments of the function to execute.
:param exceptions: an exception or a tuple of exceptions to catch. default: Exception.
:param tries: the maximum number of attempts. default: -1 (infinite).
:param delay: initial delay between attempts. default: 0.
:param max_delay: the maximum value of delay. default: None (no limit).
:param backoff: multiplier applied to delay between attempts. default: 1 (no backoff).
:param jitter: extra seconds added to delay between attempts. default: 0.
fixed if a number, random if a range tuple (min, max)
:param logger: logger.warning(fmt, error, delay) will be called on failed attempts.
default: retry.logging_logger. if None, logging is disabled.
:returns: the result of the f function.
"""
args = fargs if fargs else list()
kwargs = fkwargs if fkwargs else dict()
return __retry_internal(partial(f, *args, **kwargs), exceptions, tries, delay, max_delay, backoff, jitter, logger)