Merge pull request #4826 from bjester/load-channel-rev

Use CTE for server rev query, add tests

contentcuration/contentcuration/models.py

@@ -46,6 +46,7 @@
 from django.dispatch import receiver
 from django.utils import timezone
 from django.utils.translation import gettext as _
+from django_cte import CTEManager
 from django_cte import With
 from le_utils import proquint
 from le_utils.constants import content_kinds
@@ -1060,6 +1061,18 @@ def mark_publishing(self, user):
         self.main_tree.publishing = True
         self.main_tree.save()
 
+    def get_server_rev(self):
+        changes_cte = With(
+            Change.objects.filter(channel=self).values("server_rev", "applied"),
+        )
+        return (
+            changes_cte.queryset()
+            .with_cte(changes_cte)
+            .filter(applied=True)
+            .values_list("server_rev", flat=True)
+            .order_by("-server_rev").first()
+        ) or 0
+
     @property
     def deletion_history(self):
         return self.history.filter(action=channel_history.DELETION)
@@ -2571,6 +2584,8 @@ class Change(models.Model):
     # will be falsy.
     unpublishable = models.BooleanField(null=True, blank=True, default=False)
 
+    objects = CTEManager()
+
     @classmethod
     def _create_from_change(
         cls,

contentcuration/contentcuration/tests/test_models.py

@@ -15,6 +15,7 @@
 from contentcuration.constants import channel_history
 from contentcuration.constants import user_history
 from contentcuration.models import AssessmentItem
+from contentcuration.models import Change
 from contentcuration.models import Channel
 from contentcuration.models import ChannelHistory
 from contentcuration.models import ChannelSet
@@ -32,6 +33,7 @@
 from contentcuration.models import UserHistory
 from contentcuration.tests import testdata
 from contentcuration.tests.base import StudioTestCase
+from contentcuration.viewsets.sync.constants import DELETED
 
 
 @pytest.fixture
@@ -251,6 +253,29 @@ def test_filter_edit_queryset__private_channel__anonymous(self):
         queryset = Channel.filter_edit_queryset(self.base_queryset, user=self.anonymous_user)
         self.assertQuerysetDoesNotContain(queryset, pk=channel.id)
 
+    def test_get_server_rev(self):
+        channel = testdata.channel()
+
+        def create_change(server_rev, applied):
+            return Change(
+                channel=channel,
+                server_rev=server_rev,
+                user=self.admin_user,
+                created_by=self.admin_user,
+                change_type=DELETED,
+                table=Channel.__name__,
+                applied=applied,
+                kwargs={},
+            )
+
+        Change.objects.bulk_create([
+            create_change(1, True),
+            create_change(2, True),
+            create_change(3, False),
+        ])
+
+        self.assertEqual(channel.get_server_rev(), 2)
+
 
 class ContentNodeTestCase(PermissionQuerysetTestCase):
     @property

contentcuration/contentcuration/views/base.py

@@ -1,22 +1,17 @@
 import json
-from builtins import str
 from urllib.parse import urlsplit
 
 from django.conf import settings
 from django.contrib.auth.decorators import login_required
 from django.core.cache import cache
-from django.core.exceptions import PermissionDenied
 from django.db.models import Count
-from django.db.models import Exists
 from django.db.models import IntegerField
 from django.db.models import OuterRef
 from django.db.models import Subquery
 from django.db.models import UUIDField
 from django.db.models.functions import Cast
 from django.http import HttpResponse
-from django.http import HttpResponseBadRequest
 from django.http import HttpResponseForbidden
-from django.http import HttpResponseNotFound
 from django.shortcuts import redirect
 from django.shortcuts import render
 from django.urls import is_valid_path
@@ -30,6 +25,7 @@
 from django.views.decorators.http import require_POST
 from django.views.i18n import LANGUAGE_QUERY_PARAMETER
 from django_celery_results.models import TaskResult
+from django_cte import With
 from rest_framework.authentication import BasicAuthentication
 from rest_framework.authentication import SessionAuthentication
 from rest_framework.authentication import TokenAuthentication
@@ -41,21 +37,18 @@
 from rest_framework.response import Response
 
 from .json_dump import json_for_parse_from_data
-from .json_dump import json_for_parse_from_serializer
 from contentcuration.constants import channel_history
 from contentcuration.decorators import browser_is_supported
 from contentcuration.models import Change
 from contentcuration.models import Channel
 from contentcuration.models import ChannelHistory
-from contentcuration.models import ChannelSet
 from contentcuration.models import ContentKind
 from contentcuration.models import CustomTaskMetadata
 from contentcuration.models import DEFAULT_USER_PREFERENCES
 from contentcuration.models import Language
 from contentcuration.models import License
 from contentcuration.serializers import SimplifiedChannelProbeCheckSerializer
 from contentcuration.utils.messages import get_messages
-from contentcuration.viewsets.channelset import PublicChannelSetSerializer
 
 PUBLIC_CHANNELS_CACHE_DURATION = 30  # seconds
 PUBLIC_CHANNELS_CACHE_KEYS = {
@@ -317,7 +310,7 @@ def channel(request, channel_id):
         if channel.deleted:
             channel_error = 'CHANNEL_EDIT_ERROR_CHANNEL_DELETED'
         else:
-            channel_rev = Change.objects.filter(applied=True, channel=channel).values_list("server_rev", flat=True).order_by("-server_rev").first() or 0
+            channel_rev = channel.get_server_rev()
 
     return render(
         request,