Bring back cleanup thread

core/cleanup.py

@@ -0,0 +1,71 @@
+import logging
+from datetime import datetime
+from threading import Event, Thread
+
+import pytz
+
+from core.data_store import DATA_STORE
+
+
+class CleanupTimer:
+    """Provides a timed cleanup of the spot list."""
+
+    def __init__(self):
+        """Constructor"""
+
+        self._cleanup_interval = None
+        self.last_cleanup_time = datetime.min.replace(tzinfo=pytz.UTC)
+        self.status = "Starting"
+        self._thread = None
+        self._stop_event = Event()
+
+    def setup(self, cleanup_interval):
+        self._cleanup_interval = cleanup_interval
+
+    def start(self):
+        """Start the cleanup timer"""
+
+        self._thread = Thread(target=self._run, daemon=True)
+        self._thread.start()
+
+    def stop(self):
+        """Stop any threads and prepare for application shutdown"""
+
+        self._stop_event.set()
+
+    def _run(self):
+        while not self._stop_event.wait(timeout=self._cleanup_interval):
+            self._cleanup()
+
+    def _cleanup(self):
+        """Perform cleanup and reschedule next timer"""
+
+        try:
+            for i in list(DATA_STORE.spots.iterkeys()):
+                try:
+                    spot = DATA_STORE.spots[i]
+                    if spot.expired():
+                        DATA_STORE.spots.delete(i)
+                except KeyError:
+                    # Must have already been deleted, OK with that
+                    pass
+            for i in list(DATA_STORE.alerts.iterkeys()):
+                try:
+                    alert = DATA_STORE.alerts[i]
+                    if alert.expired():
+                        DATA_STORE.alerts.delete(i)
+                except KeyError:
+                    # Must have already been deleted, OK with that
+                    pass
+
+            self.status = "OK"
+            self.last_cleanup_time = datetime.now(pytz.UTC)
+
+        except Exception:
+            self.status = "Error"
+            logging.exception("Exception in Cleanup thread")
+            self._stop_event.wait(timeout=1)
+
+
+# Global object
+CLEANUP_TIMER = CleanupTimer()