strix

commit c25ed627acd78e8ad396ffa1084e8ea9c005832e
parent 2dee4af2a7b02540074aaca98cc2211ab04e63ca
Author: Brian C. Lane <bcl@brianlane.com>
Date:   Sat,  9 Apr 2022 18:18:33 -0700

events: Fix expiring and deleting old events

The first problem was that I left in clearing the remove dict. This
prevented it from even trying to remove them.

The second big problem was that TemporaryDirectory tries to unlink the
directory when it gets garbage collected, which resulted in the UI
getting stuck unexpectedly and in a hard to debug way (no logs, no
errors on the console). Replaced it with mkdtemp() to fix that.

Also removed the force_expire logic, and just set the time out so that
it wouldn't expire during startup unless startup took took long, even
then it would still respect the counter. Previously it was checking
every single time an event was added to the queue, resulting in a
potentially massive slowdown at startup.

Diffstat:
M
src/strix/events.py
 | 
33
++++++++++++---------------------

1 file changed, 12 insertions(+), 21 deletions(-)
diff --git a/src/strix/events.py b/src/strix/events.py
@@ -30,8 +30,7 @@ class EventCacheClass:
     def __init__(self):
         self._log = None
         self._base_dir = "/invalid/path/for/expire"
-        self._last_check = datetime(1985, 10, 26, 1, 22, 0)
-        self._force_expire = False
+        self._last_check = datetime.now()
         self._check_cache = 60
         self._keep_days = 9999
         self._lock = threading.Lock()
@@ -77,10 +76,6 @@ class EventCacheClass:
         with self._lock:
             self._last_check = datetime(1985, 10, 26, 1, 22, 0)
 
-    def force_expire(self, force=False):
-        with self._lock:
-            self._force_expire = force
-
     def log_info(self, *args):
         if self._log:
             self._log.info(*args)
@@ -92,13 +87,11 @@ class EventCacheClass:
     def _expire_events(self):
         start = datetime.now()
 
-        if not self._force_expire:
-            if start - self._last_check < timedelta(minutes=self._check_cache):
-                return
+        if start - self._last_check < timedelta(minutes=self._check_cache):
+            return
         self._last_check = datetime.now()
 
-        if not self._force_expire:
-            self.log_info("Checking cache...")
+        self.log_info("Checking cache...")
 
         remove = {}
         for e in self._cache:
@@ -111,18 +104,15 @@ class EventCacheClass:
                     else:
                         remove[daypath] = [e]
 
-        if not self._force_expire:
-            self.log_info(f"Done checking cache in {datetime.now()-start}")
+        self.log_info(f"Done checking cache in {datetime.now()-start}")
 
-        remove = {}
         if len(remove) == 0:
             return
 
-        self.log_info(f"Removing {len(remove)} days")
+        self.log_info(f"Removing {len(remove)} directories")
 
         # Create the temporary delete_queue directory
-        tdir = tempfile.TemporaryDirectory(dir=os.path.join(self._base_dir, "delete_queue"))
-        delete_queue = tdir.name
+        delete_queue = tempfile.mkdtemp(dir=os.path.join(self._base_dir, "delete_queue"))
 
         # Move each day's directory to the temporary delete_queue directory
         for daypath in remove:
@@ -145,7 +135,7 @@ class EventCacheClass:
             for e in remove[daypath]:
                 del self._cache[e]
 
-        self.log_info(f"Expire of {len(remove)} days took: {datetime.now()-start}")
+        self.log_info(f"Expire of {len(remove)} directories took: {datetime.now()-start}")
 
         def dth_fn(delete_queue):
             shutil.rmtree(delete_queue, ignore_errors=True)
@@ -165,14 +155,15 @@ def preload_cache(log, base_dir):
     log.info("Pre-loading event cache...")
     start = datetime(1985, 10, 26, 1, 22, 0)
     total = timedelta()
-    EventCache.force_expire(True)
     for camera in sorted(c for c in os.listdir(base_dir) if c.startswith("Camera")):
-        end   = datetime.now()
+        end = datetime.now()
         _ = camera_events(log, base_dir, camera, start, end, 0, 0)
         log.info(f"{camera} event cache loaded in {datetime.now()-end} seconds")
         total += datetime.now()-end
     log.info(f"Event cache loaded in {total} seconds")
-    EventCache.force_expire(False)
+
+    # Next event will check for expired entries
+    EventCache.reset_check()
 
 
 def path_to_dt(path):