Initial Commit

lib/apscheduler/triggers/cron/__init__.py

@@ -0,0 +1,176 @@
+from datetime import datetime, timedelta
+
+from tzlocal import get_localzone
+import six
+
+from apscheduler.triggers.base import BaseTrigger
+from apscheduler.triggers.cron.fields import BaseField, WeekField, DayOfMonthField, DayOfWeekField, DEFAULT_VALUES
+from apscheduler.util import datetime_ceil, convert_to_datetime, datetime_repr, astimezone
+
+
+class CronTrigger(BaseTrigger):
+    """
+    Triggers when current time matches all specified time constraints, similarly to how the UNIX cron scheduler works.
+
+    :param int|str year: 4-digit year
+    :param int|str month: month (1-12)
+    :param int|str day: day of the (1-31)
+    :param int|str week: ISO week (1-53)
+    :param int|str day_of_week: number or name of weekday (0-6 or mon,tue,wed,thu,fri,sat,sun)
+    :param int|str hour: hour (0-23)
+    :param int|str minute: minute (0-59)
+    :param int|str second: second (0-59)
+    :param datetime|str start_date: earliest possible date/time to trigger on (inclusive)
+    :param datetime|str end_date: latest possible date/time to trigger on (inclusive)
+    :param datetime.tzinfo|str timezone: time zone to use for the date/time calculations
+                                         (defaults to scheduler timezone)
+
+    .. note:: The first weekday is always **monday**.
+    """
+
+    FIELD_NAMES = ('year', 'month', 'day', 'week', 'day_of_week', 'hour', 'minute', 'second')
+    FIELDS_MAP = {
+        'year': BaseField,
+        'month': BaseField,
+        'week': WeekField,
+        'day': DayOfMonthField,
+        'day_of_week': DayOfWeekField,
+        'hour': BaseField,
+        'minute': BaseField,
+        'second': BaseField
+    }
+
+    __slots__ = 'timezone', 'start_date', 'end_date', 'fields'
+
+    def __init__(self, year=None, month=None, day=None, week=None, day_of_week=None, hour=None, minute=None,
+                 second=None, start_date=None, end_date=None, timezone=None):
+        if timezone:
+            self.timezone = astimezone(timezone)
+        elif start_date and start_date.tzinfo:
+            self.timezone = start_date.tzinfo
+        elif end_date and end_date.tzinfo:
+            self.timezone = end_date.tzinfo
+        else:
+            self.timezone = get_localzone()
+
+        self.start_date = convert_to_datetime(start_date, self.timezone, 'start_date')
+        self.end_date = convert_to_datetime(end_date, self.timezone, 'end_date')
+
+        values = dict((key, value) for (key, value) in six.iteritems(locals())
+                      if key in self.FIELD_NAMES and value is not None)
+        self.fields = []
+        assign_defaults = False
+        for field_name in self.FIELD_NAMES:
+            if field_name in values:
+                exprs = values.pop(field_name)
+                is_default = False
+                assign_defaults = not values
+            elif assign_defaults:
+                exprs = DEFAULT_VALUES[field_name]
+                is_default = True
+            else:
+                exprs = '*'
+                is_default = True
+
+            field_class = self.FIELDS_MAP[field_name]
+            field = field_class(field_name, exprs, is_default)
+            self.fields.append(field)
+
+    def _increment_field_value(self, dateval, fieldnum):
+        """
+        Increments the designated field and resets all less significant fields to their minimum values.
+
+        :type dateval: datetime
+        :type fieldnum: int
+        :return: a tuple containing the new date, and the number of the field that was actually incremented
+        :rtype: tuple
+        """
+
+        values = {}
+        i = 0
+        while i < len(self.fields):
+            field = self.fields[i]
+            if not field.REAL:
+                if i == fieldnum:
+                    fieldnum -= 1
+                    i -= 1
+                else:
+                    i += 1
+                continue
+
+            if i < fieldnum:
+                values[field.name] = field.get_value(dateval)
+                i += 1
+            elif i > fieldnum:
+                values[field.name] = field.get_min(dateval)
+                i += 1
+            else:
+                value = field.get_value(dateval)
+                maxval = field.get_max(dateval)
+                if value == maxval:
+                    fieldnum -= 1
+                    i -= 1
+                else:
+                    values[field.name] = value + 1
+                    i += 1
+
+        difference = datetime(**values) - dateval.replace(tzinfo=None)
+        return self.timezone.normalize(dateval + difference), fieldnum
+
+    def _set_field_value(self, dateval, fieldnum, new_value):
+        values = {}
+        for i, field in enumerate(self.fields):
+            if field.REAL:
+                if i < fieldnum:
+                    values[field.name] = field.get_value(dateval)
+                elif i > fieldnum:
+                    values[field.name] = field.get_min(dateval)
+                else:
+                    values[field.name] = new_value
+
+        difference = datetime(**values) - dateval.replace(tzinfo=None)
+        return self.timezone.normalize(dateval + difference)
+
+    def get_next_fire_time(self, previous_fire_time, now):
+        if previous_fire_time:
+            start_date = max(now, previous_fire_time + timedelta(microseconds=1))
+        else:
+            start_date = max(now, self.start_date) if self.start_date else now
+
+        fieldnum = 0
+        next_date = datetime_ceil(start_date).astimezone(self.timezone)
+        while 0 <= fieldnum < len(self.fields):
+            field = self.fields[fieldnum]
+            curr_value = field.get_value(next_date)
+            next_value = field.get_next_value(next_date)
+
+            if next_value is None:
+                # No valid value was found
+                next_date, fieldnum = self._increment_field_value(next_date, fieldnum - 1)
+            elif next_value > curr_value:
+                # A valid, but higher than the starting value, was found
+                if field.REAL:
+                    next_date = self._set_field_value(next_date, fieldnum, next_value)
+                    fieldnum += 1
+                else:
+                    next_date, fieldnum = self._increment_field_value(next_date, fieldnum)
+            else:
+                # A valid value was found, no changes necessary
+                fieldnum += 1
+
+            # Return if the date has rolled past the end date
+            if self.end_date and next_date > self.end_date:
+                return None
+
+        if fieldnum >= 0:
+            return next_date
+
+    def __str__(self):
+        options = ["%s='%s'" % (f.name, f) for f in self.fields if not f.is_default]
+        return 'cron[%s]' % (', '.join(options))
+
+    def __repr__(self):
+        options = ["%s='%s'" % (f.name, f) for f in self.fields if not f.is_default]
+        if self.start_date:
+            options.append("start_date='%s'" % datetime_repr(self.start_date))
+        return '<%s (%s)>' % (self.__class__.__name__, ', '.join(options))