Speedup views of AKPlan

Make sure event is only loaded once
Massively reduce amount of SQL queries (e.g., plan view reduced from multiple queries per AK where over half of them are duplicates down to only 2 queries -- independent of AK count)
Replace software-side list constructions with in-database operations

AKModel/views.py

@@ -25,7 +25,8 @@ class EventSlugMixin:
 
     def _load_event(self):
         # Find event based on event slug
-        self.event = get_object_or_404(Event, slug=self.kwargs.get("event_slug", None))
+        if self.event is None:
+            self.event = get_object_or_404(Event, slug=self.kwargs.get("event_slug", None))
 
     def get(self, request, *args, **kwargs):
         self._load_event()

AKPlan/templates/AKPlan/plan_index.html

@@ -81,7 +81,7 @@
 {% block content %}
     <div class="float-right">
         <ul class="nav nav-pills">
-            {% if event.room_set.count > 0 %}
+            {% if rooms|length > 0 %}
                 <li class="nav-item dropdown">
                     <a class="nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button"
                        aria-haspopup="true"
@@ -94,13 +94,13 @@
                     </div>
                 </li>
             {% endif %}
-            {% if event.aktrack_set.count > 0 %}
+            {% if tracks|length > 0 %}
                 <li class="nav-item dropdown">
                     <a class="nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button"
                        aria-haspopup="true"
                        aria-expanded="false">{% trans "Tracks" %}</a>
                     <div class="dropdown-menu">
-                        {% for t in event.aktrack_set.all %}
+                        {% for t in tracks %}
                             <a class="dropdown-item"
                                href="{% url "plan:plan_track" event_slug=event.slug pk=t.pk %}">{{ t }}</a>
                         {% endfor %}

AKPlan/templates/AKPlan/plan_room.html

@@ -16,7 +16,7 @@
 
 {% block encode %}
 [
-    {% for slot in room.akslot_set.all %}
+    {% for slot in slots %}
         {% if slot.start %}
             {'title': '{{ slot.ak }}',
             'start': '{{ slot.start | timezone:event.timezone | date:"Y-m-d H:i:s" }}',

AKPlan/views.py

@@ -18,7 +18,7 @@ class PlanIndexView(FilterByEventSlugMixin, ListView):
 
     def get_queryset(self):
         # Ignore slots not scheduled yet
-        return super().get_queryset().filter(start__isnull=False)
+        return super().get_queryset().filter(start__isnull=False).select_related('ak', 'room', 'ak__category')
 
     def get_context_data(self, *, object_list=None, **kwargs):
         context = super().get_context_data(object_list=object_list, **kwargs)
@@ -54,6 +54,8 @@ class PlanIndexView(FilterByEventSlugMixin, ListView):
         if settings.PLAN_SHOW_HIERARCHY:
             context["buildings"] = sorted(buildings)
 
+        context["tracks"] = self.event.aktrack_set.all()
+
         return context
 
 
@@ -94,6 +96,11 @@ class PlanRoomView(FilterByEventSlugMixin, DetailView):
     model = Room
     context_object_name = "room"
 
+    def get_context_data(self, *, object_list=None, **kwargs):
+        context = super().get_context_data(object_list=object_list, **kwargs)
+        context["slots"] = AKSlot.objects.filter(room=context['room']).select_related('ak', 'ak__category', 'ak__track')
+        return context
+
 
 class PlanTrackView(FilterByEventSlugMixin, DetailView):
     template_name = "AKPlan/plan_track.html"
@@ -102,9 +109,5 @@ class PlanTrackView(FilterByEventSlugMixin, DetailView):
 
     def get_context_data(self, *, object_list=None, **kwargs):
         context = super().get_context_data(object_list=object_list, **kwargs)
-
-        context["slots"] = []
-        for ak in context["track"].ak_set.all():
-            context["slots"].extend(ak.akslot_set.all())
-
+        context["slots"] = AKSlot.objects.filter(event=self.event, ak__track=context['track']).select_related('ak', 'room', 'ak__category')
         return context