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Adds support for seconds in crontab

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This commit is contained in:
Josiah Carlson 2017-10-16 15:30:24 -07:00
parent 0d4251e6d0
commit 65c85e8d7b
5 changed files with 86 additions and 46 deletions
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1
Makefile
View file

@ -13,6 +13,7 @@ test:
python3.3 -m tests.test_crontab
python3.4 -m tests.test_crontab
python3.5 -m tests.test_crontab
python3.6 -m tests.test_crontab
upload:
python setup.py sdist upload

28
README.rst
View file

@ -15,16 +15,24 @@ should next be executed.
Comparing the below chart to http://en.wikipedia.org/wiki/Cron#CRON_expression
you will note that W and # symbols are not supported.
============= =========== ================= ===========================
Field Name Mandatory Allowed Values Allowed Special Characters
============= =========== ================= ===========================
Minutes Yes 0-59 \* / , -
Hours Yes 0-23 \* / , -
Day of month Yes 1-31 \* / , - ? L
Month Yes 1-12 or JAN-DEC \* / , -
Day of week Yes 0-6 or SUN-SAT \* / , - ? L
Year No 1970-2099 \* / , -
============= =========== ================= ===========================
============= =========== ================= ============== ===========================
Field Name Mandatory Allowed Values Default Value Allowed Special Characters
============= =========== ================= ============== ===========================
Seconds No 0-59 0 \* / , -
Minutes Yes 0-59 N/A \* / , -
Hours Yes 0-23 N/A \* / , -
Day of month Yes 1-31 N/A \* / , - ? L
Month Yes 1-12 or JAN-DEC N/A \* / , -
Day of week Yes 0-6 or SUN-SAT N/A \* / , - ? L
Year No 1970-2099 * \* / , -
============= =========== ================= ============== ===========================
If your cron entry has 5 values, minutes-day of week are used, default seconds
is and default year is appended. If your cron entry has 6 values, minutes-year
are used, and default seconds are prepended.
As such, only 5-7 value crontab entries are accepted (and mangled to 7 values,
as necessary).
Sample individual crontab fields

94
crontab/_crontab.py
View file

@ -18,6 +18,7 @@ import sys
import warnings
_ranges = [
(0, 59),
(0, 59),
(0, 23),
(1, 31),
@ -25,7 +26,12 @@ _ranges = [
(0, 6),
(1970, 2099),
]
ENTRIES = len(_ranges)
SECOND_OFFSET, MINUTE_OFFSET, HOUR_OFFSET, DAY_OFFSET, MONTH_OFFSET, WEEK_OFFSET, YEAR_OFFSET = range(ENTRIES)
_attribute = [
'second',
'minute',
'hour',
'day',
@ -34,9 +40,10 @@ _attribute = [
'year'
]
_alternate = {
3: {'jan': 1, 'feb': 2, 'mar': 3, 'apr': 4, 'may': 5, 'jun': 6,
MONTH_OFFSET: {'jan': 1, 'feb': 2, 'mar': 3, 'apr': 4, 'may': 5, 'jun': 6,
'jul': 7, 'aug': 8, 'sep': 9, 'oct': 10, 'nov':11, 'dec':12},
4: {'sun': 0, 'mon': 1, 'tue': 2, 'wed': 3, 'thu': 4, 'fri': 5, 'sat': 6},
WEEK_OFFSET: {'sun': 0, 'mon': 1, 'tue': 2, 'wed': 3, 'thu': 4, 'fri': 5,
'sat': 6},
}
_aliases = {
'@yearly': '0 0 1 1 *',
@ -64,6 +71,7 @@ if sys.version_info >= (3, 0):
else:
_number_types = (int, long, float)
SECOND = timedelta(seconds=1)
MINUTE = timedelta(minutes=1)
HOUR = timedelta(hours=1)
DAY = timedelta(days=1)
@ -99,12 +107,14 @@ def _year_incr(dt, m):
return YEAR
_increments = [
lambda *a: SECOND,
lambda *a: MINUTE,
lambda *a: HOUR,
lambda *a: DAY,
_month_incr,
lambda *a: DAY,
_year_incr,
lambda dt,x: dt.replace(second=0),
lambda dt,x: dt.replace(minute=0),
lambda dt,x: dt.replace(hour=0),
lambda dt,x: dt.replace(day=1) if x > DAY else dt,
@ -146,20 +156,23 @@ def _day_decr_reset(dt, x):
return dt - DAY
_decrements = [
lambda *a: -SECOND,
lambda *a: -MINUTE,
lambda *a: -HOUR,
_day_decr,
_month_decr,
lambda *a: -DAY,
_year_decr,
lambda dt,x: dt.replace(second=59),
lambda dt,x: dt.replace(minute=59),
lambda dt,x: dt.replace(hour=23),
_day_decr_reset,
lambda dt,x: dt.replace(month=12) if x < -DAY else dt,
lambda dt,x: dt,
_year_decr,
]
Matcher = namedtuple('Matcher', 'minute, hour, day, month, weekday, year')
Matcher = namedtuple('Matcher', 'second, minute, hour, day, month, weekday, year')
def _assert(condition, message, *args):
if not condition:
@ -168,7 +181,7 @@ def _assert(condition, message, *args):
class _Matcher(object):
__slots__ = 'allowed', 'end', 'any', 'input', 'which', 'split'
def __init__(self, which, entry):
_assert(0 <= which <= 5,
_assert(0 <= which <= YEAR_OFFSET,
"improper number of cron entries specified")
self.input = entry.lower()
self.split = self.input.split(',')
@ -185,6 +198,7 @@ class _Matcher(object):
_assert(self.end is not None,
"improper item specification: %r", entry.lower()
)
self.allowed = frozenset(self.allowed)
def __call__(self, v, dt):
for i, x in enumerate(self.split):
@ -224,6 +238,14 @@ class _Matcher(object):
return _ranges[self.which][0] > other
return all(item > other for item in self.allowed)
def __eq__(self, other):
if self.any:
return other.any
return self.allowed == other.allowed
def __hash__(self):
return hash((self.any, self.allowed))
def _parse_crontab(self, which, entry):
'''
This parses a single crontab field and returns the data necessary for
@ -250,7 +272,7 @@ class _Matcher(object):
if '-' in it:
start, end = map(_fix, it.split('-'))
# Allow "sat-sun"
if which == 4 and end == 0:
if which in (DAY_OFFSET, WEEK_OFFSET) and end == 0:
end = 7
elif it == '*':
start = _start
@ -262,13 +284,14 @@ class _Matcher(object):
return set([start])
_assert(_start <= start <= _end_limit,
"range start value %r out of range [%r, %r]",
start, _start, _end_limit)
"%s range start value %r out of range [%r, %r]",
_attribute[which], start, _start, _end_limit)
_assert(_start <= end <= _end_limit,
"range end value %r out of range [%r, %r]",
end, _start, _end_limit)
"%s range end value %r out of range [%r, %r]",
_attribute[which], end, _start, _end_limit)
_assert(start <= end,
"range start value %r > end value %r", start, end)
"%s range start value %r > end value %r",
_attribute[which], start, end)
return set(range(start, end+1, increment or 1))
_start, _end = _ranges[which]
@ -276,19 +299,19 @@ class _Matcher(object):
# wildcards
if entry in ('*', '?'):
if entry == '?':
_assert(which in (2, 4),
_assert(which in (DAY_OFFSET, WEEK_OFFSET),
"cannot use '?' in the %r field", _attribute[which])
return None, _end
# last day of the month
if entry == 'l':
_assert(which == 2,
_assert(which == DAY_OFFSET,
"you can only specify a bare 'L' in the 'day' field")
return None, _end
# for the last 'friday' of the month, for example
elif entry.startswith('l'):
_assert(which == 4,
_assert(which == WEEK_OFFSET,
"you can only specify a leading 'L' in the 'weekday' field")
es, _, ee = entry[1:].partition('-')
_assert((entry[1:].isdigit() and 0 <= int(es) <= 7) or
@ -306,14 +329,14 @@ class _Matcher(object):
increment)
# allow Sunday to be specified as weekday 7
if which == 4:
if which == WEEK_OFFSET:
_end_limit = 7
# handle singles and ranges
good = _parse_piece(entry)
# change Sunday to weekday 0
if which == 4 and 7 in good:
if which == WEEK_OFFSET and 7 in good:
good.discard(7)
good.add(0)
@ -330,13 +353,16 @@ class CronTab(object):
This constructs the full matcher struct.
'''
crontab = _aliases.get(crontab, crontab)
matchers = [_Matcher(which, entry)
for which, entry in enumerate(crontab.split())]
ct = crontab.split()
if len(ct) == 5:
ct.insert(0, '0')
ct.append('*')
elif len(ct) == 6:
ct.insert(0, '0')
_assert(len(ct) == 7,
"improper number of cron entries specified; got %i need 5 to 7"%(len(ct,)))
if len(matchers) == 5:
matchers.append(_Matcher(5, '*'))
_assert(len(matchers) == 6,
"improper number of cron entries specified")
matchers = [_Matcher(which, entry) for which, entry in enumerate(ct)]
return Matcher(*matchers)
@ -347,7 +373,7 @@ class CronTab(object):
'''
at = _attribute[index]
attr = getattr(dt, at)
if at == 'isoweekday':
if index == WEEK_OFFSET:
attr = attr() % 7
return self.matchers[index](attr, dt)
@ -356,11 +382,11 @@ class CronTab(object):
How long to wait in seconds before this crontab entry can next be
executed.
'''
if default_utc is WARN_CHANGE and (isinstance(now, _number_types) or (now and not now.tzinfo)):
if default_utc is WARN_CHANGE and (isinstance(now, _number_types) or (now and not now.tzinfo) or now is None):
warnings.warn(WARNING_CHANGE_MESSAGE, FutureWarning, 2)
default_utc = False
now = now or (datetime.utcnow() if default_utc else datetime.now())
now = now or (datetime.utcnow() if default_utc and default_utc is not WARN_CHANGE else datetime.now())
if isinstance(now, _number_types):
now = datetime.utcfromtimestamp(now) if default_utc else datetime.fromtimestamp(now)
@ -368,12 +394,12 @@ class CronTab(object):
# reasonable future/past start time
onow, now = now, now.replace(tzinfo=None)
tz = onow.tzinfo
future = now.replace(second=0, microsecond=0) + increments[0]()
future = now.replace(microsecond=0) + increments[0]()
if future < now:
# we are going backwards...
_test = lambda: future.year < self.matchers.year
if now.second or now.microsecond:
future = now.replace(second=0, microsecond=0)
if now.microsecond:
future = now.replace(microsecond=0)
else:
# we are going forwards
_test = lambda: self.matchers.year < future.year
@ -383,21 +409,25 @@ class CronTab(object):
# gets us performance without sacrificing correctness. Still more
# complicated than a brute-force approach, but also orders of
# magnitude faster in basically all cases.
to_test = 5
to_test = ENTRIES - 1
while to_test >= 0:
if not self._test_match(to_test, future):
inc = increments[to_test](future, self.matchers)
future += inc
for i in xrange(0, to_test):
future = increments[6+i](future, inc)
future = increments[ENTRIES+i](future, inc)
try:
if _test():
return None
to_test = 5
except:
print(future, type(future), type(inc))
raise
to_test = ENTRIES-1
continue
to_test -= 1
# verify the match
match = [self._test_match(i, future) for i in xrange(6)]
match = [self._test_match(i, future) for i in xrange(ENTRIES)]
_assert(all(match),
"\nYou have discovered a bug with crontab, please notify the\n" \
"author with the following information:\n" \
@ -421,7 +451,7 @@ class CronTab(object):
def test(self, entry):
if isinstance(entry, _number_types):
entry = datetime.utcfromtimestamp(entry)
for index in xrange(6):
for index in xrange(ENTRIES):
if not self._test_match(index, entry):
return False
return True

2
setup.py
View file

@ -10,7 +10,7 @@ except:
setup(
name='crontab',
version='0.21.3',
version='0.22.0',
description='Parse and use crontab schedules in Python',
author='Josiah Carlson',
author_email='josiah.carlson@gmail.com',

3
tests/test_crontab.py
View file

@ -52,6 +52,7 @@ class TestCrontab(unittest.TestCase):
assert p == datetime.datetime(2013, 1, 4, 15, 45), p
def test_normal(self):
self._run_test('*/5 * * * * * *', 5)
self._run_test('* * * * *', 60)
self._run_test('0 * * * *', 3600)
self._run_test('0 0 * * *', 86400)
@ -145,7 +146,7 @@ class TestCrontab(unittest.TestCase):
self.assertRaises(ValueError, lambda: CronTab('* *'))
self.assertRaises(ValueError, lambda: CronTab('* * *'))
self.assertRaises(ValueError, lambda: CronTab('* * * *'))
self.assertRaises(ValueError, lambda: CronTab('* * * * * * *'))
self.assertRaises(ValueError, lambda: CronTab('* * * * * * * *'))
self.assertRaises(ValueError, lambda: CronTab('-1 * * * *'))
self.assertRaises(ValueError, lambda: CronTab('* mon-tue * * *'))
self.assertRaises(ValueError, lambda: CronTab('* * * feb-jan *'))