Wait on stop event when possible

Generally eliminate the `while True` loops while waiting for a stop
event and prefer to condition the loops on if the stop event is set,
blocking on that where it makes sense.  This generally comes in 3
flavors.  First and simplest, when there is a sleep and the stop event
is the only thing the loop blocks on, instead do a check using
`stop_event.wait(timeout)` to instead block on the stop event for the
designated amount of time. Second, when there is a different event that
is blocking in the loop, condition the loop on `stop_event.is_set()`
rather than breaking when it is set. Finally, when there is a separate
internal condition that requires a counter, have the loop iterate over
the counter and use `if stop_event.wait(timeout)` internal to the loop.

frigate/record.py

@@ -1,4 +1,5 @@
 import datetime
+import itertools
 import json
 import logging
 import os
@@ -114,19 +115,14 @@ class RecordingMaintainer(threading.Thread):
                 p.unlink(missing_ok=True)
 
     def run(self):
-        counter = 0
-        self.expire_files()
-        while True:
-            if self.stop_event.is_set():
+        for counter in itertools.cycle(range(60)):
+            if self.stop_event.wait(10):
                 logger.info(f"Exiting recording maintenance...")
                 break
 
             # only expire events every 10 minutes, but check for new files every 10 seconds
-            time.sleep(10)
-            counter = counter + 1
-            if counter > 60:
+            if counter == 0:
                 self.expire_files()
                 remove_empty_directories(RECORD_DIR)
-                counter = 0
 
             self.move_files()