Merge pull request #1365 from niphlod/feature/scheduler_crontab

repeats via cronline expression

gluon/scheduler.py

@@ -9,9 +9,9 @@ Background processes made simple
 ---------------------------------
 """
 from __future__ import print_function
-from gluon._compat import Queue, long, iteritems
 
 import os
+import re
 import time
 import multiprocessing
 import sys
@@ -24,13 +24,13 @@ import logging
 import optparse
 import tempfile
 import types
-
+from functools import reduce
 from json import loads, dumps
-from gluon import DAL, Field, IS_NOT_EMPTY, IS_IN_SET, IS_NOT_IN_DB
+from gluon import DAL, Field, IS_NOT_EMPTY, IS_IN_SET, IS_NOT_IN_DB, IS_EMPTY_OR
 from gluon import IS_INT_IN_RANGE, IS_DATETIME, IS_IN_DB
 from gluon.utils import web2py_uuid
+from gluon._compat import Queue, long, iteritems
 from gluon.storage import Storage
-from functools import reduce
 
 USAGE = """
 ## Example
@@ -71,23 +71,6 @@ http://127.0.0.1:8000/myapp/appadmin/select/db?query=db.scheduler_run.id>0
 ## view workers
 http://127.0.0.1:8000/myapp/appadmin/select/db?query=db.scheduler_worker.id>0
 
-## To install the scheduler as a permanent daemon on Linux (w/ Upstart), put
-## the following into /etc/init/web2py-scheduler.conf:
-## (This assumes your web2py instance is installed in <user>'s home directory,
-## running as <user>, with app <myapp>, on network interface eth0.)
-
-description "web2py task scheduler"
-start on (local-filesystems and net-device-up IFACE=eth0)
-stop on shutdown
-respawn limit 8 60 # Give up if restart occurs 8 times in 60 seconds.
-exec sudo -u <user> python /home/<user>/web2py/web2py.py -K <myapp>
-respawn
-
-## You can then start/stop/restart/check status of the daemon with:
-sudo start web2py-scheduler
-sudo stop web2py-scheduler
-sudo restart web2py-scheduler
-sudo status web2py-scheduler
 """
 
 path = os.getcwd()
@@ -160,7 +143,7 @@ class TaskReport(object):
 
 
 class JobGraph(object):
-    """Experimental: dependencies amongs tasks"""
+    """Experimental: dependencies amongs tasks."""
 
     def __init__(self, db, job_name):
         self.job_name = job_name or 'job_0'
@@ -216,9 +199,216 @@ class JobGraph(object):
             db.rollback()
             return None
 
+
+class CronParser(object):
+
+    def __init__(self, cronline, base=None):
+        self.cronline = cronline
+        self.sched = base or datetime.datetime.now()
+        self.task = None
+
+    @staticmethod
+    def _rangetolist(s, period='min'):
+        retval = []
+        if s.startswith('*'):
+            if period == 'min':
+                s = s.replace('*', '0-59', 1)
+            elif period == 'hr':
+                s = s.replace('*', '0-23', 1)
+            elif period == 'dom':
+                s = s.replace('*', '1-31', 1)
+            elif period == 'mon':
+                s = s.replace('*', '1-12', 1)
+            elif period == 'dow':
+                s = s.replace('*', '0-6', 1)
+        m = re.compile(r'(\d+)-(\d+)/(\d+)')
+        match = m.match(s)
+        if match:
+            min_, max_ = int(match.group(1)), int(match.group(2)) + 1
+            step_ = int(match.group(3))
+        else:
+            m = re.compile(r'(\d+)/(\d+)')
+            ranges_max = {'min': 59, 'hr': 23, 'mon': 12, 'dom': 31, 'dow': 7}
+            match = m.match(s)
+            if match:
+                min_, max_ = int(match.group(1)), ranges_max[period] + 1
+                step_ = int(match.group(2))
+        if match:
+            for i in range(min_, max_, step_):
+                retval.append(i)
+        return retval
+
+    @staticmethod
+    def _sanitycheck(values, period):
+        if period == 'min':
+            check = all(0 <= i <= 59 for i in values)
+        elif period == 'hr':
+            check = all(0 <= i <= 23 for i in values)
+        elif period == 'dom':
+            check = all(1 <= i <= 31 or i == 'l' for i in values)
+        elif period == 'mon':
+            check = all(1 <= i <= 12 for i in values)
+        elif period == 'dow':
+            check = all(0 <= i <= 7 for i in values)
+        return check
+
+    def _parse(self):
+        line = self.cronline.lower()
+        task = {}
+        if line.startswith('@yearly'):
+            line = line.replace('@yearly', '0 0 1 1 *')
+        elif line.startswith('@annually'):
+            line = line.replace('@annually', '0 0 1 1 *')
+        elif line.startswith('@monthly'):
+            line = line.replace('@monthly', '0 0 1 * *')
+        elif line.startswith('@weekly'):
+            line = line.replace('@weekly', '0 0 * * 0')
+        elif line.startswith('@daily'):
+            line = line.replace('@daily', '0 0 * * *')
+        elif line.startswith('@midnight'):
+            line = line.replace('@midnight', '0 0 * * *')
+        elif line.startswith('@hourly'):
+            line = line.replace('@hourly', '0 * * * *')
+        params = line.strip().split()
+        if len(params) < 5:
+            raise ValueError('Invalid cron line (too short)')
+        elif len(params) > 5:
+            raise ValueError('Invalid cron line (too long)')
+        daysofweek = {'sun': 0, 'mon': 1, 'tue': 2, 'wed': 3, 'thu': 4,
+                      'fri': 5, 'sat': 6}
+        monthsofyear = {'jan': 1, 'feb': 2, 'mar': 3, 'apr': 4, 'may': 5,
+                        'jun': 6, 'jul': 7, 'aug': 8, 'sep': 9, 'oct': 10,
+                        'nov': 11, 'dec': 12, 'l': 'l'}
+        for (s, i) in zip(params[:5], ['min', 'hr', 'dom', 'mon', 'dow']):
+            if s not in [None, '*']:
+                task[i] = []
+                vals = s.split(',')
+                for val in vals:
+                    if i == 'dow':
+                        refdict = daysofweek
+                    elif i == 'mon':
+                        refdict = monthsofyear
+                    if i in ('dow', 'mon') and '-' in val and '/' not in val:
+                        isnum = val.split('-')[0].isdigit()
+                        if isnum:
+                            val = '%s/1' % val
+                        else:
+                            val = '-'.join([str(refdict[v])
+                                           for v in val.split('-')])
+                    if val != '-1' and '-' in val and '/' not in val:
+                        val = '%s/1' % val
+                    if '/' in val:
+                        task[i] += self._rangetolist(val, i)
+                    elif val.isdigit() or val == '-1':
+                        task[i].append(int(val))
+                    elif i in ('dow', 'mon'):
+                        if val in refdict:
+                            task[i].append(refdict[val])
+                    elif i == 'dom' and val == 'l':
+                        task[i].append(val)
+                if not task[i]:
+                    raise ValueError('Invalid cron value (%s)' % s)
+                if not self._sanitycheck(task[i], i):
+                    raise ValueError('Invalid cron value (%s)' % s)
+                task[i] = sorted(task[i])
+        self.task = task
+
+    @staticmethod
+    def _get_next_dow(sched, task):
+        task_dow = [a % 7 for a in task['dow']]
+        while sched.isoweekday() % 7 not in task_dow:
+            sched += datetime.timedelta(days=1)
+        return sched
+
+    @staticmethod
+    def _get_next_dom(sched, task):
+        if task['dom'] == ['l']:
+            last_feb = 29 if sched.year % 4 == 0 else 28
+            lastdayofmonth = [
+                31, last_feb, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+            ]
+            task_dom = [lastdayofmonth[sched.month - 1]]
+        else:
+            task_dom = task['dom']
+        while sched.day not in task_dom:
+            sched += datetime.timedelta(days=1)
+        return sched
+
+    @staticmethod
+    def _get_next_mon(sched, task):
+        while sched.month not in task['mon']:
+            if sched.month < 12:
+                sched = sched.replace(month=sched.month + 1)
+            else:
+                sched = sched.replace(month=1, year=sched.year + 1)
+        return sched
+
+    @staticmethod
+    def _getnext_hhmm(sched, task, add_to=True):
+        if add_to:
+            sched += datetime.timedelta(minutes=1)
+        if 'min' in task:
+            while sched.minute not in task['min']:
+                sched += datetime.timedelta(minutes=1)
+        if 'hr' in task and sched.hour not in task['hr']:
+            while sched.hour not in task['hr']:
+                sched += datetime.timedelta(hours=1)
+        return sched
+
+    def _getnext_date(self, sched, task):
+        if 'dow' in task and 'dom' in task:
+            dow = self._get_next_dow(sched, task)
+            dom = self._get_next_dom(sched, task)
+            sched = min(dow, dom)
+        elif 'dow' in task:
+            sched = self._get_next_dow(sched, task)
+        elif 'dom' in task:
+            sched = self._get_next_dom(sched, task)
+        if 'mon' in task:
+            sched = self._get_next_mon(sched, task)
+        return sched.replace(hour=0, minute=0)
+
+    def get_next(self):
+        """Get next date according to specs."""
+        if not self.task:
+            self._parse()
+        task = self.task
+        sched = self.sched
+        x = 0
+        while x < 1000:  # avoid potential max recursions
+            x += 1
+            try:
+                next_date = self._getnext_date(sched, task)
+            except (ValueError, OverflowError) as e:
+                raise ValueError('Invalid cron expression (%s)' % e)
+            if next_date.date() > self.sched.date():
+                # we rolled date, check for valid hhmm
+                sched = self._getnext_hhmm(next_date, task, False)
+                break
+            else:
+                # same date, get next hhmm
+                sched_time = self._getnext_hhmm(sched, task, True)
+                if sched_time.date() > sched.date():
+                    # we rolled date again :(
+                    sched = sched_time
+                else:
+                    sched = sched_time
+                    break
+        else:
+            raise ValueError('Potential bug found, please submit your '
+                             'cron expression to the authors')
+        self.sched = sched
+        return sched
+
+    def __iter__(self):
+        """Support iteration."""
+        return self
+
+    __next__ = next = get_next
+
 # the two functions below deal with simplejson decoding as unicode, esp for the dict decode
 # and subsequent usage as function Keyword arguments unicode variable names won't work!
-# borrowed from http://stackoverflow.com/questions/956867/how-to-get-string-objects-instead-unicode-ones-from-json-in-python
+# borrowed from http://stackoverflow.com/questions/956867/
 
 
 def _decode_list(lst):
@@ -321,7 +511,7 @@ def executor(queue, task, out):
 
 
 class MetaScheduler(threading.Thread):
-    """Base class documenting scheduler's base methods"""
+    """Base class documenting scheduler's base methods."""
 
     def __init__(self):
         threading.Thread.__init__(self)
@@ -377,7 +567,7 @@ class MetaScheduler(threading.Thread):
                 while not out.empty():
                     tout += out.get()
                 if tout:
-                    logger.debug(' partial output: "%s"' % str(tout))
+                    logger.debug(' partial output: "%s"', str(tout))
                     if CLEAROUT in tout:
                         task_output = tout[
                             tout.rfind(CLEAROUT) + len(CLEAROUT):]
@@ -428,7 +618,7 @@ class MetaScheduler(threading.Thread):
         self.have_heartbeat = False
 
     def terminate_process(self):
-        """Terminates any running tasks (internal use only)"""
+        """Terminate any running tasks (internal use only)"""
         try:
             self.process.terminate()
         except:
@@ -468,6 +658,22 @@ TASK_STATUS = (QUEUED, RUNNING, COMPLETED, FAILED, TIMEOUT, STOPPED, EXPIRED)
 RUN_STATUS = (RUNNING, COMPLETED, FAILED, TIMEOUT, STOPPED)
 WORKER_STATUS = (ACTIVE, PICK, DISABLED, TERMINATE, KILL, STOP_TASK)
 
+class IS_CRONLINE(object):
+    """
+    Validates cronline
+    """
+    def __init__(self, error_message=None):
+        self.error_message = error_message
+
+    def __call__(self, value):
+        recur = CronParser(value, datetime.datetime.now())
+        try:
+            recur.get_next()
+            return (value, None)
+        except (KeyError, ValueError) as e:
+            if not self.error_message:
+                return (value, e)
+            return (value, self.error_message)
 
 class TYPE(object):
     """
@@ -612,7 +818,10 @@ class Scheduler(MetaScheduler):
             Field('period', 'integer', default=60, comment='seconds',
                   requires=IS_INT_IN_RANGE(0, None)),
             Field('prevent_drift', 'boolean', default=False,
-                  comment='Cron-like start_times between runs'),
+                  comment='Exact start_times between runs'),
+            Field('cronline', default=None,
+                  comment='Discard "period", use this cron expr instead',
+                  requires=IS_EMPTY_OR(IS_CRONLINE())),
             Field('timeout', 'integer', default=60, comment='seconds',
                   requires=IS_INT_IN_RANGE(1, None)),
             Field('sync_output', 'integer', default=0,
@@ -665,14 +874,6 @@ class Scheduler(MetaScheduler):
         if migrate is not False:
             db.commit()
 
-    @staticmethod
-    def total_seconds(td):
-        """Backport for py2.6."""
-        if hasattr(td, 'total_seconds'):
-            return td.total_seconds()
-        else:
-            return (td.microseconds + (td.seconds + td.days * 24 * 3600) * 10 ** 6) / 10.0 ** 6
-
     def loop(self, worker_name=None):
         """Main loop.
 
@@ -694,7 +895,7 @@ class Scheduler(MetaScheduler):
         signal.signal(signal.SIGTERM, lambda signum, stack_frame: sys.exit(1))
         try:
             self.start_heartbeats()
-            while True and self.have_heartbeat:
+            while self.have_heartbeat:
                 if self.w_stats.status == DISABLED:
                     logger.debug('Someone stopped me, sleeping until better'
                                  ' times come (%s)', self.w_stats.sleep)
@@ -798,7 +999,10 @@ class Scheduler(MetaScheduler):
                 logger.info('nothing to do')
             return None
         times_run = task.times_run + 1
-        if not task.prevent_drift:
+        if task.cronline:
+            cron_recur = CronParser(task.cronline, now.replace(second=0))
+            next_run_time = cron_recur.get_next()
+        elif not task.prevent_drift:
             next_run_time = task.last_run_time + datetime.timedelta(
                 seconds=task.period
             )
@@ -806,7 +1010,7 @@ class Scheduler(MetaScheduler):
             # calc next_run_time based on available slots
             # see #1191
             next_run_time = task.start_time
-            secondspassed = self.total_seconds(now - next_run_time)
+            secondspassed = (now - next_run_time).total_seconds()
             steps = secondspassed // task.period + 1
             next_run_time += datetime.timedelta(seconds=task.period * steps)
 
@@ -1275,13 +1479,22 @@ class Scheduler(MetaScheduler):
         tuuid = 'uuid' in kwargs and kwargs.pop('uuid') or web2py_uuid()
         tname = 'task_name' in kwargs and kwargs.pop('task_name') or function
         immediate = 'immediate' in kwargs and kwargs.pop('immediate') or None
-        rtn = self.db.scheduler_task.validate_and_insert(
+        cronline = kwargs.get('cronline')
+        kwargs.update(
             function_name=function,
             task_name=tname,
             args=targs,
             vars=tvars,
             uuid=tuuid,
-            **kwargs)
+            )
+        if cronline:
+            try:
+                start_time = kwargs.get('start_time', self.now)
+                next_run_time = CronParser(cronline, start_time).get_next()
+                kwargs.update(start_time=start_time, next_run_time=next_run_time)
+            except:
+                pass
+        rtn = self.db.scheduler_task.validate_and_insert(**kwargs)
         if not rtn.errors:
             rtn.uuid = tuuid
             if immediate:

gluon/tests/test_scheduler.py

@@ -15,7 +15,7 @@ fix_sys_path(__file__)
 
 from gluon.storage import Storage
 from gluon.languages import translator
-from gluon.scheduler import JobGraph, Scheduler
+from gluon.scheduler import JobGraph, Scheduler, CronParser
 from gluon.dal import DAL
 
 
@@ -51,6 +51,355 @@ class BaseTestScheduler(unittest.TestCase):
             pass
 
 
+class CronParserTest(unittest.TestCase):
+
+    def testMinute(self):
+        # minute asterisk
+        base = datetime.datetime(2010, 1, 23, 12, 18)
+        itr = CronParser('*/1 * * * *', base)
+        n1 = itr.get_next()    # 19
+        self.assertEqual(base.year, n1.year)
+        self.assertEqual(base.month, n1.month)
+        self.assertEqual(base.day, n1.day)
+        self.assertEqual(base.hour, n1.hour)
+        self.assertEqual(base.minute, n1.minute - 1)
+        for i in range(39):  # ~ 58
+            itr.get_next()
+        n2 = itr.get_next()
+        self.assertEqual(n2.minute, 59)
+        n3 = itr.get_next()
+        self.assertEqual(n3.minute, 0)
+        self.assertEqual(n3.hour, 13)
+
+        itr = CronParser('*/5 * * * *', base)
+        n4 = itr.get_next()
+        self.assertEqual(n4.minute, 20)
+        for i in range(6):
+            itr.get_next()
+        n5 = itr.get_next()
+        self.assertEqual(n5.minute, 55)
+        n6 = itr.get_next()
+        self.assertEqual(n6.minute, 0)
+        self.assertEqual(n6.hour, 13)
+
+        base = datetime.datetime(2010, 1, 23, 12, 18)
+        itr = CronParser('4/34 * * * *', base)
+        n7 = itr.get_next()
+        self.assertEqual(n7.minute, 38)
+        self.assertEqual(n7.hour, 12)
+        n8 = itr.get_next()
+        self.assertEqual(n8.minute, 4)
+        self.assertEqual(n8.hour, 13)
+
+    def testHour(self):
+        base = datetime.datetime(2010, 1, 24, 12, 2)
+        itr = CronParser('0 */3 * * *', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.hour, 15)
+        self.assertEqual(n1.minute, 0)
+        for i in range(2):
+            itr.get_next()
+        n2 = itr.get_next()
+        self.assertEqual(n2.hour, 0)
+        self.assertEqual(n2.day, 25)
+
+    def testDay(self):
+        base = datetime.datetime(2010, 2, 24, 12, 9)
+        itr = CronParser('0 0 */3 * *', base)
+        n1 = itr.get_next()
+        # 1 4 7 10 13 16 19 22 25 28
+        self.assertEqual(n1.day, 25)
+        n2 = itr.get_next()
+        self.assertEqual(n2.day, 28)
+        n3 = itr.get_next()
+        self.assertEqual(n3.day, 1)
+        self.assertEqual(n3.month, 3)
+
+        # test leap year
+        base = datetime.datetime(1996, 2, 27)
+        itr = CronParser('0 0 * * *', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.day, 28)
+        self.assertEqual(n1.month, 2)
+        n2 = itr.get_next()
+        self.assertEqual(n2.day, 29)
+        self.assertEqual(n2.month, 2)
+
+        base2 = datetime.datetime(2000, 2, 27)
+        itr2 = CronParser('0 0 * * *', base2)
+        n3 = itr2.get_next()
+        self.assertEqual(n3.day, 28)
+        self.assertEqual(n3.month, 2)
+        n4 = itr2.get_next()
+        self.assertEqual(n4.day, 29)
+        self.assertEqual(n4.month, 2)
+
+    def testWeekDay(self):
+        base = datetime.datetime(2010, 2, 25)
+        itr = CronParser('0 0 * * sat', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.isoweekday(), 6)
+        self.assertEqual(n1.day, 27)
+        n2 = itr.get_next()
+        self.assertEqual(n2.isoweekday(), 6)
+        self.assertEqual(n2.day, 6)
+        self.assertEqual(n2.month, 3)
+
+        base = datetime.datetime(2010, 1, 25)
+        itr = CronParser('0 0 1 * wed', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.month, 1)
+        self.assertEqual(n1.day, 27)
+        self.assertEqual(n1.year, 2010)
+        n2 = itr.get_next()
+        self.assertEqual(n2.month, 2)
+        self.assertEqual(n2.day, 1)
+        self.assertEqual(n2.year, 2010)
+        n3 = itr.get_next()
+        self.assertEqual(n3.month, 2)
+        self.assertEqual(n3.day, 3)
+        self.assertEqual(n3.year, 2010)
+
+    def testMonth(self):
+        base = datetime.datetime(2010, 1, 25)
+        itr = CronParser('0 0 1 * *', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.month, 2)
+        self.assertEqual(n1.day, 1)
+        n2 = itr.get_next()
+        self.assertEqual(n2.month, 3)
+        self.assertEqual(n2.day, 1)
+        for i in range(8):
+            itr.get_next()
+        n3 = itr.get_next()
+        self.assertEqual(n3.month, 12)
+        self.assertEqual(n3.year, 2010)
+        n4 = itr.get_next()
+        self.assertEqual(n4.month, 1)
+        self.assertEqual(n4.year, 2011)
+
+        base = datetime.datetime(2010, 1, 25)
+        itr = CronParser('0 0 1 */4 *', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.month, 5)
+        self.assertEqual(n1.day, 1)
+
+        base = datetime.datetime(2010, 1, 25)
+        itr = CronParser('0 0 1 1-3 *', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.month, 2)
+        self.assertEqual(n1.day, 1)
+        n2 = itr.get_next()
+        self.assertEqual(n2.month, 3)
+        self.assertEqual(n2.day, 1)
+        n3 = itr.get_next()
+        self.assertEqual(n3.month, 1)
+        self.assertEqual(n3.day, 1)
+
+    def testSundayToThursdayWithAlphaConversion(self):
+        base = datetime.datetime(2010, 8, 25, 15, 56)
+        itr = CronParser("30 22 * * sun-thu", base)
+        n1 = itr.get_next()
+        self.assertEqual(base.year, n1.year)
+        self.assertEqual(base.month, n1.month)
+        self.assertEqual(base.day, n1.day)
+        self.assertEqual(22, n1.hour)
+        self.assertEqual(30, n1.minute)
+
+    def testISOWeekday(self):
+        base = datetime.datetime(2010, 2, 25)
+        itr = CronParser('0 0 * * 7', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.isoweekday(), 7)
+        self.assertEqual(n1.day, 28)
+        n2 = itr.get_next()
+        self.assertEqual(n2.isoweekday(), 7)
+        self.assertEqual(n2.day, 7)
+        self.assertEqual(n2.month, 3)
+        base = datetime.datetime(2010, 2, 22)
+        itr = CronParser('0 0 * * */2', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.isoweekday(), 2)
+        self.assertEqual(n1.day, 23)
+        n2 = itr.get_next()
+        self.assertEqual(n2.isoweekday(), 4)
+        self.assertEqual(n2.day, 25)
+
+    def testBug2(self):
+
+        base = datetime.datetime(2012, 1, 1, 0, 0)
+        itr = CronParser('0 * * 3 *', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.year, base.year)
+        self.assertEqual(n1.month, 3)
+        self.assertEqual(n1.day, base.day)
+        self.assertEqual(n1.hour, base.hour)
+        self.assertEqual(n1.minute, base.minute)
+
+        n2 = itr.get_next()
+        self.assertEqual(n2.year, base.year)
+        self.assertEqual(n2.month, 3)
+        self.assertEqual(n2.day, base.day)
+        self.assertEqual(n2.hour, base.hour + 1)
+        self.assertEqual(n2.minute, base.minute)
+
+        n3 = itr.get_next()
+        self.assertEqual(n3.year, base.year)
+        self.assertEqual(n3.month, 3)
+        self.assertEqual(n3.day, base.day)
+        self.assertEqual(n3.hour, base.hour + 2)
+        self.assertEqual(n3.minute, base.minute)
+
+    def testBug3(self):
+        base = datetime.datetime(2013, 3, 1, 12, 17, 34, 257877)
+        c = CronParser('00 03 16,30 * *', base)
+
+        n1 = c.get_next()
+        self.assertEqual(n1.month, 3)
+        self.assertEqual(n1.day, 16)
+
+        n2 = c.get_next()
+        self.assertEqual(n2.month, 3)
+        self.assertEqual(n2.day, 30)
+
+        n3 = c.get_next()
+        self.assertEqual(n3.month, 4)
+        self.assertEqual(n3.day, 16)
+
+    def test_rangeGenerator(self):
+        base = datetime.datetime(2013, 3, 4, 0, 0)
+        itr = CronParser('1-9/2 0 1 * *', base)
+        n1 = itr.get_next()
+        n2 = itr.get_next()
+        n3 = itr.get_next()
+        n4 = itr.get_next()
+        n5 = itr.get_next()
+        self.assertEqual(n1.minute, 1)
+        self.assertEqual(n2.minute, 3)
+        self.assertEqual(n3.minute, 5)
+        self.assertEqual(n4.minute, 7)
+        self.assertEqual(n5.minute, 9)
+
+    def test_iterGenerator(self):
+        base = datetime.datetime(2013, 3, 4, 0, 0)
+        itr = CronParser('1-9/2 0 1 * *', base)
+        x = 0
+        for n in itr:
+            x += 1
+            if x > 4:
+                break
+        self.assertEqual(n.minute, 9)
+
+    def test_invalidcron(self):
+        base = datetime.datetime(2013, 3, 4, 0, 0)
+        itr = CronParser('5 4 31 2 *', base)
+        self.assertRaises(ValueError, itr.get_next)
+        itr = CronParser('* * 5-1 * *', base)
+        self.assertRaises(ValueError, itr.get_next)
+        itr = CronParser('* * * janu-jun *', base)
+        self.assertRaises(KeyError, itr.get_next)
+        itr = CronParser('* * * * * *', base)
+        self.assertRaises(ValueError, itr.get_next)
+        itr = CronParser('* * * *', base)
+        self.assertRaises(ValueError, itr.get_next)
+
+    def testLastDayOfMonth(self):
+        base = datetime.datetime(2015, 9, 4)
+        itr = CronParser('0 0 L * *', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.month, 9)
+        self.assertEqual(n1.day, 30)
+        n2 = itr.get_next()
+        self.assertEqual(n2.month, 10)
+        self.assertEqual(n2.day, 31)
+        n3 = itr.get_next()
+        self.assertEqual(n3.month, 11)
+        self.assertEqual(n3.day, 30)
+        n4 = itr.get_next()
+        self.assertEqual(n4.month, 12)
+        self.assertEqual(n4.day, 31)
+
+        base = datetime.datetime(1996, 2, 27)
+        itr = CronParser('0 0 L * *', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.day, 29)
+        self.assertEqual(n1.month, 2)
+        n2 = itr.get_next()
+        self.assertEqual(n2.day, 31)
+        self.assertEqual(n2.month, 3)
+
+    def testSpecialExpr(self):
+        base = datetime.datetime(2000, 1, 1)
+        itr = CronParser('@yearly', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.day, 1)
+        self.assertEqual(n1.month, 1)
+        self.assertEqual(n1.year, base.year + 1)
+        self.assertEqual(n1.hour, 0)
+        self.assertEqual(n1.minute, 0)
+
+        itr = CronParser('@annually', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.day, 1)
+        self.assertEqual(n1.month, 1)
+        self.assertEqual(n1.year, base.year + 1)
+        self.assertEqual(n1.hour, 0)
+        self.assertEqual(n1.minute, 0)
+
+        itr = CronParser('@monthly', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.day, 1)
+        self.assertEqual(n1.month, base.month + 1)
+        self.assertEqual(n1.year, base.year)
+        self.assertEqual(n1.hour, 0)
+        self.assertEqual(n1.minute, 0)
+
+        itr = CronParser('@weekly', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.day, 2)
+        self.assertEqual(n1.month, base.month)
+        self.assertEqual(n1.year, base.year)
+        self.assertEqual(n1.hour, 0)
+        self.assertEqual(n1.minute, 0)
+        n2 = itr.get_next()
+        self.assertEqual(n2.day, 9)
+        self.assertEqual(n2.month, base.month)
+        self.assertEqual(n2.year, base.year)
+        self.assertEqual(n2.hour, 0)
+        self.assertEqual(n2.minute, 0)
+        n3 = itr.get_next()
+        self.assertEqual(n3.day, 16)
+        self.assertEqual(n3.month, base.month)
+        self.assertEqual(n3.year, base.year)
+        self.assertEqual(n3.hour, 0)
+        self.assertEqual(n3.minute, 0)
+
+        itr = CronParser('@daily', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.day, 2)
+        self.assertEqual(n1.month, base.month)
+        self.assertEqual(n1.year, base.year)
+        self.assertEqual(n1.hour, 0)
+        self.assertEqual(n1.minute, 0)
+
+        itr = CronParser('@midnight', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.day, 2)
+        self.assertEqual(n1.month, base.month)
+        self.assertEqual(n1.year, base.year)
+        self.assertEqual(n1.hour, 0)
+        self.assertEqual(n1.minute, 0)
+
+        itr = CronParser('@hourly', base)
+        n1 = itr.get_next()
+        self.assertEqual(n1.day, 1)
+        self.assertEqual(n1.month, base.month)
+        self.assertEqual(n1.year, base.year)
+        self.assertEqual(n1.hour, 1)
+        self.assertEqual(n1.minute, 0)
+
+
+
 class TestsForJobGraph(BaseTestScheduler):
 
     def testJobGraph(self):