Make ical feed generation of meetings not slow

lego/apps/events/permissions.py

@@ -9,7 +9,7 @@
 log = get_logger()
 
 
-class EventPermissionHandler(PermissionHandler):
+class EventPermissionHandler(PermissionHandler["Event"]):
     perms_without_object = [CREATE, "administrate"]
 
     def event_type_keyword_permissions(self, event_type, perm):

lego/apps/ical/utils.py

@@ -59,7 +59,8 @@ def add_meeting_to_ical_feed(feed, meeting, user):
         start_datetime=meeting.start_time,
         end_datetime=meeting.end_time,
         location=meeting.location,
-        transparency="OPAQUE" if user in meeting.participants else "TRANSPARENT",
+        # This uses an annotation on the queryset for performance reasons
+        transparency="OPAQUE" if meeting.user_participating else "TRANSPARENT",
     )
 
 

lego/apps/ical/viewsets.py

@@ -1,5 +1,6 @@
 from datetime import timedelta
 
+from django.db.models import Q
 from django.utils import timezone
 from rest_framework import decorators, permissions, viewsets
 from rest_framework.permissions import IsAuthenticated
@@ -11,7 +12,8 @@
 from lego.apps.ical.authentication import ICalTokenAuthentication
 from lego.apps.ical.models import ICalToken
 from lego.apps.ical.serializers import ICalTokenSerializer
-from lego.apps.meetings.models import Meeting
+from lego.apps.meetings import constants as meeting_constants
+from lego.apps.meetings.models import Meeting, MeetingInvitation
 from lego.apps.permissions.utils import get_permission_handler
 
 
@@ -86,13 +88,24 @@ def personal(self, request):
         calendar_type = constants.TYPE_PERSONAL
         feed = utils.generate_ical_feed(request, calendar_type)
 
-        permission_handler = get_permission_handler(Event)
-        following_events = permission_handler.filter_queryset(
+        event_permission_handler = get_permission_handler(Event)
+        following_events = event_permission_handler.filter_queryset(
             request.user, Event.objects.filter(followers__follower_id=request.user.id)
         )
 
-        permission_handler = get_permission_handler(Meeting)
-        meetings = permission_handler.filter_queryset(request.user, Meeting.objects)
+        meeting_permission_handler = get_permission_handler(Meeting)
+
+        attending_invites = MeetingInvitation.objects.filter(
+            status=meeting_constants.ATTENDING, user=request.user
+        )
+        meetings = meeting_permission_handler.filter_queryset(
+            request.user,
+            Meeting.objects.annotate(
+                # Annotate the queryset with participating status for use in the feed generation.
+                # Otherwise lookups are very expensive
+                user_participating=Q(invitations__in=attending_invites)
+            ),
+        )
 
         utils.add_events_to_ical_feed(feed, following_events)
         utils.add_meetings_to_ical_feed(feed, meetings, request.user)

lego/apps/permissions/permissions.py

@@ -1,14 +1,25 @@
-from django.db.models import Q
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Generic, Iterable, Sequence, Type, TypeVar
+
+from django.db.models import Q, QuerySet
 
 from lego.apps.permissions.constants import CREATE, LIST, VIEW
 from lego.apps.permissions.models import ObjectPermissionsModel
+from lego.utils.models import BasisModel
 
+if TYPE_CHECKING:
+    from lego.apps.users.models import User
 
-def _check_intersection(first, second):
+
+def _check_intersection(first, second) -> bool:
     return len(set(first).intersection(set(second))) > 0
 
 
-class PermissionHandler:
+T = TypeVar("T", bound=BasisModel)
+
+
+class PermissionHandler(Generic[T]):
     """
     The permission handler defines how permissions should be handled on a model
 
@@ -45,13 +56,19 @@
 
     perms_without_object = [CREATE]
 
-    def permissions_grant(self, permissions, user, obj=None, queryset=None):
+    def permissions_grant(
+        self,
+        permissions: Sequence[str],
+        user: User,
+        obj: T | None = None,
+        queryset: QuerySet[T] | None = None,
+    ) -> list[str]:
         """
         Lookup possible permissions the user has access to.
         """
         permissions = list(set(permissions))
 
-        filtered_permissions = []
+        filtered_permissions: Iterable[str] = []
         if obj is not None:
             filtered_permissions = filter(
                 lambda perm: user.has_perm(perm, obj), permissions
@@ -63,7 +80,13 @@
 
         return list(filtered_permissions)
 
-    def has_object_level_permissions(self, user, perm, obj=None, queryset=None):
+    def has_object_level_permissions(
+        self,
+        user: User,
+        perm: str,
+        obj: T | None = None,
+        queryset: QuerySet[T] | None = None,
+    ) -> bool:
         """
         Check whether the queryset or object requires a permission check at object level.
         This function should only be used by the api permission backend.
@@ -107,13 +130,13 @@
 
     def has_perm(
         self,
-        user,
-        perm,
-        obj=None,
-        queryset=None,
+        user: User,
+        perm: str,
+        obj: T | None = None,
+        queryset: QuerySet[T] | None = None,
         check_keyword_permissions=True,
-        **kwargs
-    ):
+        **kwargs,
+    ) -> bool:
         """
         Check permission on a object.
         """
@@ -161,7 +184,9 @@
 
         return False
 
-    def filter_queryset(self, user, queryset, **kwargs):
+    def filter_queryset(
+        self, user: User, queryset: QuerySet[T], **kwargs
+    ) -> QuerySet[T]:
         """
         Filter queryset based on object-level permissions.
         We currently only supports queryset filtering on ObjectPermissionsModels.
@@ -184,7 +209,9 @@
 
         return queryset
 
-    def require_auth(self, perm, obj=None, queryset=None):
+    def require_auth(
+        self, perm: str, obj: T | None = None, queryset: QuerySet[T] | None = None
+    ) -> bool:
         require_auth = self.authentication_map.get(perm, self.default_require_auth)
         if not require_auth:
             return False
@@ -197,10 +224,10 @@
 
         return True
 
-    def is_authenticated(self, user):
+    def is_authenticated(self, user: User) -> bool:
         return user and user.is_authenticated
 
-    def keyword_permission(self, model, perm):
+    def keyword_permission(self, model: Type[BasisModel], perm: str) -> str:
         """
         Create default permission string based on the model class, action and default_permission
         format. This is used when no permission is provided for a action in the permission_map.
@@ -212,7 +239,9 @@
         }
         return self.default_keyword_permission.format(**kwargs)
 
-    def required_keyword_permissions(self, model, perm):
+    def required_keyword_permissions(
+        self, model: Type[BasisModel], perm: str
+    ) -> list[str]:
         """
         Get required keyword permissions based on the action and model class.
         Override the permission_map to create custom permissions, the default_keyword_permission
@@ -221,11 +250,11 @@
 
         return self.permission_map.get(perm, [self.keyword_permission(model, perm)])
 
-    def created_by(self, user, obj):
+    def created_by(self, user: User, obj: T) -> bool:
         created_by = getattr(obj, "created_by_id", None)
         return created_by == user.id
 
-    def has_object_permissions(self, user, perm, obj):
+    def has_object_permissions(self, user: User, perm: str, obj: T) -> bool:
         if perm in self.safe_methods:
             # Check can_view
             if _check_intersection(

lego/apps/permissions/utils.py

@@ -1,11 +1,16 @@
+from typing import TypeVar
+
 from lego.apps.permissions.permissions import PermissionHandler
 
 # isort:skip
 
 default_permission_handler = PermissionHandler()
 
 
-def get_permission_handler(model):
+T = TypeVar("T")
+
+
+def get_permission_handler(model: T) -> PermissionHandler[T]:
     """
     Try to get the permission handler used by the model or use the default handler.
     """

pyproject.toml

@@ -71,6 +71,7 @@ coreapi = "2.3.3"
 [tool.poetry.group.dev.dependencies]
 django-debug-toolbar = "4.0.0"
 tox = "4.5.0"
+tblib = "^1.7.0"
 
 [tool.poetry.group.coverage.dependencies]
 coverage = "7.2.3"