Make the migration middleware faster, second attempt

awx/main/middleware.py

@@ -9,7 +9,7 @@ import urllib.parse
 from django.conf import settings
 from django.contrib.auth import logout
 from django.contrib.auth.models import User
-from django.db.migrations.executor import MigrationExecutor
+from django.db.migrations.recorder import MigrationRecorder
 from django.db import connection
 from django.shortcuts import redirect
 from django.apps import apps
@@ -17,9 +17,11 @@ from django.utils.deprecation import MiddlewareMixin
 from django.utils.translation import gettext_lazy as _
 from django.urls import reverse, resolve
 
+from awx.main import migrations
 from awx.main.utils.named_url_graph import generate_graph, GraphNode
 from awx.conf import fields, register
 from awx.main.utils.profiling import AWXProfiler
+from awx.main.utils.common import memoize
 
 
 logger = logging.getLogger('awx.main.middleware')
@@ -198,9 +200,21 @@ class URLModificationMiddleware(MiddlewareMixin):
             request.path_info = new_path
 
 
+@memoize(ttl=20)
+def is_migrating():
+    last_applied = MigrationRecorder(connection).migration_qs.order_by('-applied').only('name').first().name
+    last_number = int(last_applied.split('_', 1)[0])
+    for migration_name in dir(migrations):
+        try:
+            migration_number = int(migration_name.split('_', 1)[0])
+        except ValueError:
+            continue
+        if migration_number > last_number:
+            return True
+    return False
+
+
 class MigrationRanCheckMiddleware(MiddlewareMixin):
     def process_request(self, request):
-        executor = MigrationExecutor(connection)
-        plan = executor.migration_plan(executor.loader.graph.leaf_nodes())
-        if bool(plan) and getattr(resolve(request.path), 'url_name', '') != 'migrations_notran':
+        if is_migrating() and getattr(resolve(request.path), 'url_name', '') != 'migrations_notran':
             return redirect(reverse("ui:migrations_notran"))