add argument singlejob to TaskScheduler

README.md

@@ -49,7 +49,7 @@ The basic idea is to instantiate one or multiple schedulers and map specific ino
 pyinotifyd has different schedulers to schedule tasks with an optional delay. The advantages of using a scheduler are consistent logging and the possibility to cancel delayed tasks. Furthermore, schedulers have the ability to differentiate between files and directories.
 
 ### TaskScheduler
-Schedule a custom python method *job* with an optional *delay* in seconds. Skip scheduling of tasks for files and/or directories according to *files* and *dirs* arguments. If there already is a scheduled task, re-schedule it with *delay*. Use *logname* in log messages. All additional modules, functions and variables that are defined in the config file and are needed within the *job*, need to be passed as dictionary to the TaskManager through *global_vars*.  
+Schedule a custom python method *job* with an optional *delay* in seconds. Skip scheduling of tasks for files and/or directories according to *files* and *dirs* arguments. If there already is a scheduled task, re-schedule it with *delay*. Use *logname* in log messages. All additional modules, functions and variables that are defined in the config file and are needed within the *job*, need to be passed as dictionary to the TaskManager through *global_vars*. If you want to limit the scheduler to run only one job at a time, set *singlejob* to True.  
 All arguments except for *job* are optional.
 ```python
 # Please note that pyinotifyd uses pythons asyncio for asynchronous task execution.
@@ -71,7 +71,8 @@ task_sched = TaskScheduler(
     dirs=False,
     delay=0,
     logname="sched",
-    global_vars=globals())
+    global_vars=globals(),
+    singlejob=False)
 ```
 
 ### ShellScheduler

pyinotifyd/misc/config.py.default

@@ -6,15 +6,16 @@
 #import logging
 #
 #async def custom_job(event, task_id):
-#    asyncio.sleep(1)
+#    await asyncio.sleep(1)
 #    logging.info(f"{task_id}: execute example task: {event}")
 #
 #task_sched = TaskScheduler(
 #    job=custom_job,
 #    files=True,
 #    dirs=False,
-#    delay=10
+#    delay=10,
-#    global_vars=globals())
+#    global_vars=globals(),
+#    singlejob=False)
 
 
 ###########################
@@ -25,7 +26,8 @@
 #    cmd="/usr/local/bin/task.sh {maskname} {pathname} {src_pathname}",
 #    files=True,
 #    dirs=False,
-#    delay=10)
+#    delay=10,
+#    singlejob=False)
 
 
 #################################

pyinotifyd/scheduler.py

@@ -52,7 +52,7 @@ class TaskScheduler:
             self.cancelable = cancelable
 
     def __init__(self, job, files=True, dirs=False, delay=0, logname="sched",
-                 loop=None, global_vars={}):
+                 loop=None, global_vars={}, singlejob=False):
         assert iscoroutinefunction(job), \
             f"job: expected coroutine, got {type(job)}"
         assert isinstance(files, bool), \
@@ -71,6 +71,7 @@ class TaskScheduler:
         self._log = logging.getLogger((logname or __name__))
         self._loop = (loop or asyncio.get_event_loop())
         self._globals = global_vars
+        self._singlejob = singlejob
         self._tasks = {}
         self._pause = False
 
@@ -105,6 +106,9 @@ class TaskScheduler:
             else:
                 self._log.info("all remainig tasks completed")
 
+    def taskindex(self, event):
+        return "singlejob" if self._singlejob else event.pathname
+
     async def _run_job(self, event, task_state, restart=False):
         logger = SchedulerLogger(self._log, {
             "event": event,
@@ -112,7 +116,7 @@ class TaskScheduler:
 
         if self._delay > 0:
             task_state.task = self._loop.create_task(
-                asyncio.sleep(self._delay, loop=self._loop))
+                asyncio.sleep(self._delay))
             try:
                 if restart:
                     prefix = "re-"
@@ -145,7 +149,8 @@ class TaskScheduler:
         else:
             logger.info("task finished")
         finally:
-            del self._tasks[event.pathname]
+            task_index = self.taskindex(event)
+            del self._tasks[task_index]
 
     async def process_event(self, event):
         if not ((not event.dir and self._files) or
@@ -153,9 +158,13 @@ class TaskScheduler:
             return
 
         restart = False
+        task_index = self.taskindex(event)
         try:
-            task_state = self._tasks[event.pathname]
+            task_state = self._tasks[task_index]
-
+        except KeyError:
+            task_state = TaskScheduler.TaskState()
+            self._tasks[task_index] = task_state
+        else:
             logger = SchedulerLogger(self._log, {
                 "event": event,
                 "id": task_state.id})
@@ -171,16 +180,13 @@ class TaskScheduler:
                 logger.warning("skip event due to ongoing task")
                 return
 
-        except KeyError:
-            task_state = TaskScheduler.TaskState()
-            self._tasks[event.pathname] = task_state
-
         if not self._pause:
             await self._run_job(event, task_state, restart)
 
     async def process_cancel_event(self, event):
         try:
-            task_state = self._tasks[event.pathname]
+            task_index = self.taskindex(event)
+            task_state = self._tasks[task_index]
         except KeyError:
             return
 
@@ -192,7 +198,8 @@ class TaskScheduler:
             task_state.task.cancel()
             logger.info("scheduled task cancelled")
             task_state.task = None
-            del self._tasks[event.pathname]
+            logger.info(f"{task_index}")
+            del self._tasks[task_index]
         else:
             logger.warning("skip event due to ongoing task")
 
@@ -285,7 +292,8 @@ class FileManagerRule:
 
 class FileManagerScheduler(TaskScheduler):
     def __init__(self, rules, job=None, *args, **kwargs):
-        super().__init__(*args, **kwargs, job=self._manager_job)
+        super().__init__(
+            *args, **kwargs, job=self._manager_job, singlejob=False)
 
         if not isinstance(rules, list):
             rules = [rules]