Tweak: more accurate classifier last trained time (#9004)

src/documents/classifier.py

@@ -1,6 +1,7 @@
 import logging
 import pickle
 import re
+import time
 import warnings
 from collections.abc import Iterator
 from hashlib import sha256
@@ -141,6 +142,19 @@ class DocumentClassifier:
                 ):
                     raise IncompatibleClassifierVersionError("sklearn version update")
 
+    def set_last_checked(self) -> None:
+        # save a timestamp of the last time we checked for retraining to a file
+        with Path(settings.MODEL_FILE.with_suffix(".last_checked")).open("w") as f:
+            f.write(str(time.time()))
+
+    def get_last_checked(self) -> float | None:
+        # load the timestamp of the last time we checked for retraining
+        try:
+            with Path(settings.MODEL_FILE.with_suffix(".last_checked")).open("r") as f:
+                return float(f.read())
+        except FileNotFoundError:  # pragma: no cover
+            return None
+
     def save(self) -> None:
         target_file: Path = settings.MODEL_FILE
         target_file_temp: Path = target_file.with_suffix(".pickle.part")
@@ -161,6 +175,7 @@ class DocumentClassifier:
             pickle.dump(self.storage_path_classifier, f)
 
         target_file_temp.rename(target_file)
+        self.set_last_checked()
 
     def train(self) -> bool:
         # Get non-inbox documents
@@ -229,6 +244,7 @@ class DocumentClassifier:
             and self.last_doc_change_time >= latest_doc_change
         ) and self.last_auto_type_hash == hasher.digest():
             logger.info("No updates since last training")
+            self.set_last_checked()
             # Set the classifier information into the cache
             # Caching for 50 minutes, so slightly less than the normal retrain time
             cache.set(

src/documents/views.py

@@ -15,7 +15,6 @@ from urllib.parse import quote
 from urllib.parse import urlparse
 
 import pathvalidate
-from django.apps import apps
 from django.conf import settings
 from django.contrib.auth.models import Group
 from django.contrib.auth.models import User
@@ -2174,18 +2173,14 @@ class SystemStatusView(PassUserMixin):
                     classifier_status = "WARNING"
                     raise FileNotFoundError(classifier_error)
             classifier_status = "OK"
-            task_result_model = apps.get_model("django_celery_results", "taskresult")
-            result = (
-                task_result_model.objects.filter(
-                    task_name="documents.tasks.train_classifier",
-                    status="SUCCESS",
+            classifier_last_trained = (
+                make_aware(
+                    datetime.fromtimestamp(classifier.get_last_checked()),
                 )
-                .order_by(
-                    "-date_done",
-                )
-                .first()
+                if settings.MODEL_FILE.exists()
+                and classifier.get_last_checked() is not None
+                else None
             )
-            classifier_last_trained = result.date_done if result else None
         except Exception as e:
             if classifier_status is None:
                 classifier_status = "ERROR"