Add RRule support

rq_scheduler/scheduler.py

@@ -15,7 +15,7 @@
 
 from redis import WatchError
 
-from .utils import from_unix, to_unix, get_next_scheduled_time, rationalize_until
+from .utils import from_unix, to_unix, get_next_scheduled_time, get_next_rrule_scheduled_time, rationalize_until
 
 logger = logging.getLogger(__name__)
 
@@ -298,6 +298,37 @@ def cron(self, cron_string, func, args=None, kwargs=None, repeat=None,
                               {job.id: to_unix(scheduled_time)})
         return job
 
+
+    def rrule(self, rrule_string, func, args=None, kwargs=None, repeat=None,
+             queue_name=None, result_ttl=-1, ttl=None, id=None, timeout=None, description=None, meta=None,
+             depends_on=None, on_success=None, on_failure=None, at_front: bool = False):
+        """
+        Schedule a recurring job via RRule
+        """
+        scheduled_time = get_next_rrule_scheduled_time(rrule_string)
+        if not scheduled_time:
+            return None
+
+        job = self._create_job(func, args=args, kwargs=kwargs, commit=False,
+                               result_ttl=result_ttl, ttl=ttl, id=id, queue_name=queue_name,
+                               description=description, timeout=timeout, meta=meta, depends_on=depends_on,
+                               on_success=on_success, on_failure=on_failure)
+
+        job.meta['rrule_string'] = rrule_string
+
+        if repeat is not None:
+            job.meta['repeat'] = int(repeat)
+
+        if at_front:
+            job.enqueue_at_front = True
+
+        job.save()
+
+        self.connection.zadd(self.scheduled_jobs_key,
+                              {job.id: to_unix(scheduled_time)})
+        return job
+
+
     def cancel(self, job):
         """
         Pulls a job from the scheduler queue. This function accepts either a
@@ -415,6 +446,7 @@ def enqueue_job(self, job):
         interval = job.meta.get('interval', None)
         repeat = job.meta.get('repeat', None)
         cron_string = job.meta.get('cron_string', None)
+        rrule_string = job.meta.get('rrule_string', None)
         use_local_timezone = job.meta.get('use_local_timezone', None)
 
         # If job is a repeated job, decrement counter
@@ -425,21 +457,21 @@ def enqueue_job(self, job):
         queue.enqueue_job(job, at_front=bool(job.enqueue_at_front))
         self.connection.zrem(self.scheduled_jobs_key, job.id)
 
+        # If this is a repeat job and counter has reached 0, don't repeat
+        if repeat is not None:
+            if job.meta['repeat'] == 0:
+                return
         if interval:
-            # If this is a repeat job and counter has reached 0, don't repeat
-            if repeat is not None:
-                if job.meta['repeat'] == 0:
-                    return
             self.connection.zadd(self.scheduled_jobs_key,
                                   {job.id: to_unix(datetime.utcnow()) + int(interval)})
         elif cron_string:
-            # If this is a repeat job and counter has reached 0, don't repeat
-            if repeat is not None:
-                if job.meta['repeat'] == 0:
-                    return
             next_scheduled_time = get_next_scheduled_time(cron_string, use_local_timezone=use_local_timezone)
             self.connection.zadd(self.scheduled_jobs_key,
                                  {job.id: to_unix(next_scheduled_time)})
+        elif rrule_string:
+            next_scheduled_time = get_next_rrule_scheduled_time(rrule_string)
+            self.connection.zadd(self.scheduled_jobs_key,
+                                 {job.id: to_unix(next_scheduled_time)})
 
     def enqueue_jobs(self):
         """

rq_scheduler/utils.py

@@ -1,6 +1,8 @@
 import calendar
 import crontab
 import dateutil.tz
+import dateutil.rrule
+import re
 
 from datetime import datetime, timedelta
 import logging
@@ -30,6 +32,27 @@ def get_next_scheduled_time(cron_string, use_local_timezone=False):
     return next_time.astimezone(tz)
 
 
+def get_next_rrule_scheduled_time(rrule_string):
+    """Calculate the next scheduled time by creating a rrule object
+    with a rrule string"""
+    timezone = dateutil.tz.UTC
+    ruleset = dateutil.rrule.rrulestr(rrule_string, forceset=True)
+    any_occurence = None
+    for occur in ruleset:
+        any_occurence = occur
+        break
+    if any_occurence is None:
+        return None
+    if any_occurence.tzinfo is None:
+        now = datetime.now()
+    else:
+        now = datetime.now(tz=timezone)
+    next_occurence = ruleset.after(now)
+    if next_occurence is None:
+        return None
+    return next_occurence.astimezone(timezone)
+
+
 def setup_loghandlers(level='INFO'):
     logger = logging.getLogger('rq_scheduler.scheduler')
     if not logger.handlers: