Enable Write-Ahead Logging (WAL) for SQLite to improve performance when using it.

photo21/settings.py

@@ -129,6 +129,9 @@ DATABASES = {
     "default": {
         "ENGINE": "django.db.backends.sqlite3",
         "NAME": os.path.join(BASE_DIR, "db.sqlite3"),
+        "OPTIONS": {
+            "timeout": 10,
+        },
     }
 }
 

photologue/apps.py

@@ -3,8 +3,25 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 from django.apps import AppConfig
+from django.db.backends.signals import connection_created
 
 
 class PhotologueConfig(AppConfig):
     default_auto_field = "django.db.models.AutoField"
     name = "photologue"
+
+    def ready(self):
+        from django.db import connection
+
+        def enable_sqlite_wal(sender, connection, **kwargs):
+            if connection.vendor == "sqlite":
+                cursor = connection.cursor()
+                cursor.execute("PRAGMA journal_mode=WAL;")
+                cursor.execute("PRAGMA synchronous=OFF;")
+                cursor.execute("PRAGMA journal_size_limit=67108864;")
+                cursor.execute("PRAGMA wal_autocheckpoint=1000;")
+                cursor.execute("PRAGMA cache_size=-65536;")
+                cursor.execute("PRAGMA temp_store=MEMORY;")
+                cursor.execute("PRAGMA mmap_size=268435456;")
+
+        connection_created.connect(enable_sqlite_wal)

photologue/models.py

@@ -486,7 +486,7 @@ class ImageModel(models.Model):
             self._old_image.storage.delete(
                 self._old_image.name
             )  # Delete (old) base image.
-        if self.date_taken is None or image_has_changed:
+        if (self.date_taken is None or image_has_changed) and self.image:
             # Attempt to get the date the photo was taken from the EXIF data.
             try:
                 exif_date = self.exif(self.image.file).get(