R: Optimize database queries

rsconcept/backend/apps/library/models/Editor.py

@@ -55,7 +55,7 @@ class Editor(Model):
     def set(item: int, users: Iterable[int]):
         ''' Set editors for item. '''
         processed: set[int] = set()
-        for editor_item in Editor.objects.filter(item_id=item).only('pk', 'editor_id'):
+        for editor_item in Editor.objects.filter(item_id=item).only('editor_id'):
             editor_id = editor_item.editor_id
             if editor_id not in users:
                 editor_item.delete()
@@ -74,7 +74,7 @@ class Editor(Model):
         processed: list[int] = []
         deleted: list[int] = []
         added: list[int] = []
-        for editor_item in Editor.objects.filter(item_id=item).only('pk', 'editor_id'):
+        for editor_item in Editor.objects.filter(item_id=item).only('editor_id'):
             editor_id = editor_item.editor_id
             if editor_id not in users:
                 deleted.append(editor_id)

rsconcept/backend/apps/library/models/LibraryItem.py

@@ -114,9 +114,9 @@ class LibraryItem(Model):
     def get_absolute_url(self):
         return f'/api/library/{self.pk}'
 
-    def subscribers(self) -> list[User]:
+    def subscribers(self) -> QuerySet[User]:
         ''' Get all subscribers for this item. '''
-        return [subscription.user for subscription in Subscription.objects.filter(item=self.pk).only('user')]
+        return User.objects.filter(subscription__item=self.pk)
 
     def editors(self) -> QuerySet[User]:
         ''' Get all Editors of this item. '''
@@ -126,6 +126,7 @@ class LibraryItem(Model):
         ''' Get all Versions of this item. '''
         return Version.objects.filter(item=self.pk).order_by('-time_create')
 
+    # TODO: move to View layer
     @transaction.atomic
     def save(self, *args, **kwargs):
         ''' Save updating subscriptions and connected operations. '''
@@ -134,7 +135,7 @@ class LibraryItem(Model):
         subscribe = self._state.adding and self.owner
         super().save(*args, **kwargs)
         if subscribe:
-            Subscription.subscribe(user=self.owner, item=self)
+            Subscription.subscribe(user=self.owner_id, item=self.pk)
 
     def _update_connected_operations(self):
         # using method level import to prevent circular dependency

rsconcept/backend/apps/library/models/Subscription.py

@@ -1,13 +1,8 @@
 ''' Models: Subscription. '''
-from typing import TYPE_CHECKING
-
 from django.db.models import CASCADE, ForeignKey, Model
 
 from apps.users.models import User
 
-if TYPE_CHECKING:
-    from .LibraryItem import LibraryItem
-
 
 class Subscription(Model):
     ''' User subscription to library item. '''
@@ -32,17 +27,17 @@ class Subscription(Model):
         return f'{self.user} -> {self.item}'
 
     @staticmethod
-    def subscribe(user: User, item: 'LibraryItem') -> bool:
+    def subscribe(user: int, item: int) -> bool:
         ''' Add subscription. '''
-        if Subscription.objects.filter(user=user, item=item).exists():
+        if Subscription.objects.filter(user_id=user, item_id=item).exists():
             return False
-        Subscription.objects.create(user=user, item=item)
+        Subscription.objects.create(user_id=user, item_id=item)
         return True
 
     @staticmethod
-    def unsubscribe(user: User, item: 'LibraryItem') -> bool:
+    def unsubscribe(user: int, item: int) -> bool:
         ''' Remove subscription. '''
-        sub = Subscription.objects.filter(user=user, item=item)
+        sub = Subscription.objects.filter(user_id=user, item_id=item).only('pk')
         if not sub.exists():
             return False
         sub.delete()

rsconcept/backend/apps/library/serializers/data_access.py

@@ -83,7 +83,7 @@ class LibraryItemDetailsSerializer(serializers.ModelSerializer):
         read_only_fields = ('owner', 'id', 'item_type')
 
     def get_subscribers(self, instance: LibraryItem) -> list[int]:
-        return [item.pk for item in instance.subscribers()]
+        return list(instance.subscribers().values_list('pk', flat=True))
 
     def get_editors(self, instance: LibraryItem) -> list[int]:
         return list(instance.editors().values_list('pk', flat=True))

rsconcept/backend/apps/library/tests/s_models/t_Subscription.py

@@ -37,33 +37,33 @@ class TestSubscription(TestCase):
 
     def test_subscribe(self):
         item = LibraryItem.objects.create(item_type=LibraryItemType.RSFORM, title='Test')
-        self.assertEqual(len(item.subscribers()), 0)
+        self.assertEqual(item.subscribers().count(), 0)
 
-        self.assertTrue(Subscription.subscribe(self.user1, item))
-        self.assertEqual(len(item.subscribers()), 1)
+        self.assertTrue(Subscription.subscribe(self.user1.pk, item.pk))
+        self.assertEqual(item.subscribers().count(), 1)
         self.assertTrue(self.user1 in item.subscribers())
 
-        self.assertFalse(Subscription.subscribe(self.user1, item))
-        self.assertEqual(len(item.subscribers()), 1)
+        self.assertFalse(Subscription.subscribe(self.user1.pk, item.pk))
+        self.assertEqual(item.subscribers().count(), 1)
 
-        self.assertTrue(Subscription.subscribe(self.user2, item))
-        self.assertEqual(len(item.subscribers()), 2)
+        self.assertTrue(Subscription.subscribe(self.user2.pk, item.pk))
+        self.assertEqual(item.subscribers().count(), 2)
         self.assertTrue(self.user1 in item.subscribers())
         self.assertTrue(self.user2 in item.subscribers())
 
         self.user1.delete()
-        self.assertEqual(len(item.subscribers()), 1)
+        self.assertEqual(item.subscribers().count(), 1)
 
 
     def test_unsubscribe(self):
         item = LibraryItem.objects.create(item_type=LibraryItemType.RSFORM, title='Test')
-        self.assertFalse(Subscription.unsubscribe(self.user1, item))
-        Subscription.subscribe(self.user1, item)
-        Subscription.subscribe(self.user2, item)
-        self.assertEqual(len(item.subscribers()), 2)
+        self.assertFalse(Subscription.unsubscribe(self.user1.pk, item.pk))
+        Subscription.subscribe(self.user1.pk, item.pk)
+        Subscription.subscribe(self.user2.pk, item.pk)
+        self.assertEqual(item.subscribers().count(), 2)
 
-        self.assertTrue(Subscription.unsubscribe(self.user1, item))
-        self.assertEqual(len(item.subscribers()), 1)
+        self.assertTrue(Subscription.unsubscribe(self.user1.pk, item.pk))
+        self.assertEqual(item.subscribers().count(), 1)
         self.assertTrue(self.user2 in item.subscribers())
 
-        self.assertFalse(Subscription.unsubscribe(self.user1, item))
+        self.assertFalse(Subscription.unsubscribe(self.user1.pk, item.pk))

rsconcept/backend/apps/library/tests/s_views/t_library.py

@@ -269,9 +269,9 @@ class TestLibraryViewset(EndpointTester):
         response = self.executeOK()
         self.assertFalse(response_contains(response, self.unowned))
 
-        Subscription.subscribe(user=self.user, item=self.unowned)
-        Subscription.subscribe(user=self.user2, item=self.unowned)
-        Subscription.subscribe(user=self.user2, item=self.owned)
+        Subscription.subscribe(user=self.user.pk, item=self.unowned.pk)
+        Subscription.subscribe(user=self.user2.pk, item=self.unowned.pk)
+        Subscription.subscribe(user=self.user2.pk, item=self.owned.pk)
 
         response = self.executeOK()
         self.assertTrue(response_contains(response, self.unowned))

rsconcept/backend/apps/library/views/library.py

@@ -4,9 +4,8 @@ from typing import cast
 
 from django.db import transaction
 from django.db.models import Q
-from django_filters.rest_framework import DjangoFilterBackend
 from drf_spectacular.utils import extend_schema, extend_schema_view
-from rest_framework import filters, generics
+from rest_framework import generics
 from rest_framework import status as c
 from rest_framework import viewsets
 from rest_framework.decorators import action
@@ -28,10 +27,8 @@ from .. import serializers as s
 class LibraryViewSet(viewsets.ModelViewSet):
     ''' Endpoint: Library operations. '''
     queryset = m.LibraryItem.objects.all()
+    # TODO: consider using .only() for performance
 
-    filter_backends = (DjangoFilterBackend, filters.OrderingFilter)
-    filterset_fields = ['item_type', 'owner']
-    ordering_fields = ('item_type', 'owner', 'alias', 'title', 'time_update')
     ordering = '-time_update'
 
     def get_serializer_class(self):
@@ -128,7 +125,7 @@ class LibraryViewSet(viewsets.ModelViewSet):
     def subscribe(self, request: Request, pk):
         ''' Endpoint: Subscribe current user to item. '''
         item = self._get_item()
-        m.Subscription.subscribe(user=cast(User, self.request.user), item=item)
+        m.Subscription.subscribe(user=cast(int, self.request.user.pk), item=item.pk)
         return Response(status=c.HTTP_200_OK)
 
     @extend_schema(
@@ -145,7 +142,7 @@ class LibraryViewSet(viewsets.ModelViewSet):
     def unsubscribe(self, request: Request, pk):
         ''' Endpoint: Unsubscribe current user from item. '''
         item = self._get_item()
-        m.Subscription.unsubscribe(user=cast(User, self.request.user), item=item)
+        m.Subscription.unsubscribe(user=cast(int, self.request.user.pk), item=item.pk)
         return Response(status=c.HTTP_200_OK)
 
     @extend_schema(

rsconcept/backend/apps/oss/serializers/data_access.py

@@ -48,7 +48,7 @@ class OperationCreateSerializer(serializers.Serializer):
 
     create_schema = serializers.BooleanField(default=False, required=False)
     item_data = OperationCreateData()
-    arguments = PKField(many=True, queryset=Operation.objects.all(), required=False)
+    arguments = PKField(many=True, queryset=Operation.objects.all().only('pk'), required=False)
 
     positions = serializers.ListField(
         child=OperationPositionSerializer(),
@@ -67,7 +67,7 @@ class OperationUpdateSerializer(serializers.Serializer):
 
     target = PKField(many=False, queryset=Operation.objects.all())
     item_data = OperationUpdateData()
-    arguments = PKField(many=True, queryset=Operation.objects.all(), required=False)
+    arguments = PKField(many=True, queryset=Operation.objects.all().only('oss_id', 'result_id'), required=False)
     substitutions = serializers.ListField(
         child=SubstitutionSerializerBase(),
         required=False
@@ -121,8 +121,8 @@ class OperationUpdateSerializer(serializers.Serializer):
 
 
 class OperationTargetSerializer(serializers.Serializer):
-    ''' Serializer: Delete operation. '''
-    target = PKField(many=False, queryset=Operation.objects.all())
+    ''' Serializer: Target single operation. '''
+    target = PKField(many=False, queryset=Operation.objects.all().only('oss_id', 'result_id'))
     positions = serializers.ListField(
         child=OperationPositionSerializer(),
         default=[]

rsconcept/backend/apps/rsform/serializers/data_access.py

@@ -269,7 +269,7 @@ class CstRenameSerializer(serializers.Serializer):
 
 class CstListSerializer(serializers.Serializer):
     ''' Serializer: List of constituents from one origin. '''
-    items = PKField(many=True, queryset=Constituenta.objects.all())
+    items = PKField(many=True, queryset=Constituenta.objects.all().only('schema_id'))
 
     def validate(self, attrs):
         schema = cast(LibraryItem, self.context['schema'])
@@ -291,8 +291,8 @@ class CstMoveSerializer(CstListSerializer):
 
 class SubstitutionSerializerBase(serializers.Serializer):
     ''' Serializer: Basic substitution. '''
-    original = PKField(many=False, queryset=Constituenta.objects.only('alias', 'schema'))
-    substitution = PKField(many=False, queryset=Constituenta.objects.only('alias', 'schema'))
+    original = PKField(many=False, queryset=Constituenta.objects.only('alias', 'schema_id'))
+    substitution = PKField(many=False, queryset=Constituenta.objects.only('alias', 'schema_id'))
 
 
 class CstSubstituteSerializer(serializers.Serializer):
@@ -330,8 +330,8 @@ class CstSubstituteSerializer(serializers.Serializer):
 
 class InlineSynthesisSerializer(serializers.Serializer):
     ''' Serializer: Inline synthesis operation input. '''
-    receiver = PKField(many=False, queryset=LibraryItem.objects.all())
-    source = PKField(many=False, queryset=LibraryItem.objects.all())  # type: ignore
+    receiver = PKField(many=False, queryset=LibraryItem.objects.all().only('owner_id'))
+    source = PKField(many=False, queryset=LibraryItem.objects.all().only('owner_id'))  # type: ignore
     items = PKField(many=True, queryset=Constituenta.objects.all())
     substitutions = serializers.ListField(
         child=SubstitutionSerializerBase()