Fake paginator for Ark admin page

Lifted from:
https://hakibenita.com/optimizing-the-django-admin-paginator

ark/admin.py

@@ -1,8 +1,32 @@
 from django.contrib import admin
+from django.core.paginator import Paginator
+from django.db import OperationalError, connection, transaction
+from django.utils.functional import cached_property
 
 from ark.models import User, Naan, Shoulder, Ark, Key
 
 
+class TimeLimitedPaginator(Paginator):
+    """
+    Paginator that enforces a timeout on the count operation.
+    If the operations times out, a fake bogus value is
+    returned instead.
+
+    Lifted from: https://web.archive.org/web/20210422225156/https://hakibenita.com/optimizing-the-django-admin-paginator
+    """
+
+    @cached_property
+    def count(self):
+        # We set the timeout in a db transaction to prevent it from
+        # affecting other transactions.
+        with transaction.atomic(), connection.cursor() as cursor:
+            cursor.execute("SET LOCAL statement_timeout TO 1000;")
+            try:
+                return super().count
+            except OperationalError:
+                return 9999999999
+
+
 @admin.register(User)
 class UserAdmin(admin.ModelAdmin):
     pass
@@ -22,6 +46,7 @@ class ShoulderAdmin(admin.ModelAdmin):
 class ArkAdmin(admin.ModelAdmin):
     list_display = ["ark", "url"]
     show_full_result_count = False
+    paginator = TimeLimitedPaginator
 
 
 @admin.register(Key)