Typing Part 3: events.py (#3352)

* Typing: events.py

* Remove unused variable

* Fix return Any from return statement

Not all elements from the event dict are sure to be something that can be evaluated

See e.g.: https://github.com/python/mypy/issues/5697

* Sort out Event disambiguity

There was a name collision of multiprocessing Event type and frigate events

Co-authored-by: Sebastian Englbrecht <sebastian.englbrecht@kabelmail.de>

frigate/app.py

@@ -1,7 +1,7 @@
 import logging
 import multiprocessing as mp
 from multiprocessing.queues import Queue
-from multiprocessing.synchronize import Event
+from multiprocessing.synchronize import Event as MpEvent
 import os
 import signal
 import sys
@@ -38,10 +38,10 @@ logger = logging.getLogger(__name__)
 
 class FrigateApp:
     def __init__(self) -> None:
-        self.stop_event: Event = mp.Event()
+        self.stop_event: MpEvent = mp.Event()
         self.detection_queue: Queue = mp.Queue()
         self.detectors: dict[str, ObjectDetectProcess] = {}
-        self.detection_out_events: dict[str, Event] = {}
+        self.detection_out_events: dict[str, MpEvent] = {}
         self.detection_shms: list[mp.shared_memory.SharedMemory] = []
         self.log_queue: Queue = mp.Queue()
         self.plus_api = PlusApi()

frigate/events.py

@@ -11,43 +11,55 @@ from peewee import fn
 from frigate.config import EventsConfig, FrigateConfig, RecordConfig
 from frigate.const import CLIPS_DIR
 from frigate.models import Event
+from frigate.types import CameraMetricsTypes
+
+from multiprocessing.queues import Queue
+from multiprocessing.synchronize import Event as MpEvent
+from typing import Dict
 
 logger = logging.getLogger(__name__)
 
 
-def should_insert_db(prev_event, current_event):
+def should_insert_db(prev_event: Event, current_event: Event) -> bool:
     """If current event has new clip or snapshot."""
     return (not prev_event["has_clip"] and not prev_event["has_snapshot"]) and (
         current_event["has_clip"] or current_event["has_snapshot"]
     )
 
 
-def should_update_db(prev_event, current_event):
+def should_update_db(prev_event: Event, current_event: Event) -> bool:
     """If current_event has updated fields and (clip or snapshot)."""
-    return (current_event["has_clip"] or current_event["has_snapshot"]) and (
+    if current_event["has_clip"] or current_event["has_snapshot"]:
+        if (
             prev_event["top_score"] != current_event["top_score"]
             or prev_event["entered_zones"] != current_event["entered_zones"]
             or prev_event["thumbnail"] != current_event["thumbnail"]
             or prev_event["has_clip"] != current_event["has_clip"]
             or prev_event["has_snapshot"] != current_event["has_snapshot"]
-    )
+        ):
+            return True
+    return False
 
 
 class EventProcessor(threading.Thread):
     def __init__(
-        self, config, camera_processes, event_queue, event_processed_queue, stop_event
+        self,
+        config: FrigateConfig,
+        camera_processes: dict[str, CameraMetricsTypes],
+        event_queue: Queue,
+        event_processed_queue: Queue,
+        stop_event: MpEvent,
     ):
         threading.Thread.__init__(self)
         self.name = "event_processor"
         self.config = config
         self.camera_processes = camera_processes
-        self.cached_clips = {}
         self.event_queue = event_queue
         self.event_processed_queue = event_processed_queue
-        self.events_in_process = {}
+        self.events_in_process: Dict[str, Event] = {}
         self.stop_event = stop_event
 
-    def run(self):
+    def run(self) -> None:
         # set an end_time on events without an end_time on startup
         Event.update(end_time=Event.start_time + 30).where(
             Event.end_time == None
@@ -147,14 +159,15 @@ class EventProcessor(threading.Thread):
 
 
 class EventCleanup(threading.Thread):
-    def __init__(self, config: FrigateConfig, stop_event):
+    def __init__(self, config: FrigateConfig, stop_event: MpEvent):
         threading.Thread.__init__(self)
         self.name = "event_cleanup"
         self.config = config
         self.stop_event = stop_event
         self.camera_keys = list(self.config.cameras.keys())
 
-    def expire(self, media_type):
+    def expire(self, media_type: str) -> None:
+        # TODO: Refactor media_type to enum
         ## Expire events from unlisted cameras based on the global config
         if media_type == "clips":
             retain_config = self.config.record.events.retain
@@ -253,7 +266,7 @@ class EventCleanup(threading.Thread):
                 )
                 update_query.execute()
 
-    def purge_duplicates(self):
+    def purge_duplicates(self) -> None:
         duplicate_query = """with grouped_events as (
           select id,
             label,
@@ -287,7 +300,7 @@ class EventCleanup(threading.Thread):
             .execute()
         )
 
-    def run(self):
+    def run(self) -> None:
         # only expire events every 5 minutes
         while not self.stop_event.wait(300):
             self.expire("clips")

frigate/mypy.ini

@@ -34,6 +34,9 @@ disallow_untyped_calls = false
 [mypy-frigate.const]
 ignore_errors = false
 
+[mypy-frigate.events]
+ignore_errors = false
+
 [mypy-frigate.log]
 ignore_errors = false
 

frigate/stats.py

@@ -8,7 +8,7 @@ import os
 import requests
 from typing import Optional, Any
 from paho.mqtt.client import Client
-from multiprocessing.synchronize import Event
+from multiprocessing.synchronize import Event as MpEvent
 
 from frigate.config import FrigateConfig
 from frigate.const import RECORD_DIR, CLIPS_DIR, CACHE_DIR
@@ -148,7 +148,7 @@ class StatsEmitter(threading.Thread):
         stats_tracking: StatsTrackingTypes,
         mqtt_client: Client,
         topic_prefix: str,
-        stop_event: Event,
+        stop_event: MpEvent,
     ):
         threading.Thread.__init__(self)
         self.name = "frigate_stats_emitter"

frigate/watchdog.py

@@ -7,13 +7,13 @@ import signal
 
 from frigate.object_detection import ObjectDetectProcess
 from frigate.util import restart_frigate
-from multiprocessing.synchronize import Event
+from multiprocessing.synchronize import Event as MpEvent
 
 logger = logging.getLogger(__name__)
 
 
 class FrigateWatchdog(threading.Thread):
-    def __init__(self, detectors: dict[str, ObjectDetectProcess], stop_event: Event):
+    def __init__(self, detectors: dict[str, ObjectDetectProcess], stop_event: MpEvent):
         threading.Thread.__init__(self)
         self.name = "frigate_watchdog"
         self.detectors = detectors