optimisation: Barrier Detail cache (#850)

* optimisation: Barrier Detail cache

---------

Co-authored-by: abarolo <[email protected]>
Co-authored-by: Uka Osim <[email protected]>

api/barriers/barrier_cache.py

@@ -0,0 +1,15 @@
+from django.core.cache import cache
+
+BARRIERS_PREFIX = "barriers/"
+
+
+def get(pk):
+    return cache.get(f"{BARRIERS_PREFIX}/{pk}")
+
+
+def delete(pk):
+    cache.delete(f"{BARRIERS_PREFIX}/{pk}")
+
+
+def set(pk, obj):
+    cache.set(f"{BARRIERS_PREFIX}/{pk}", obj, 120)

api/barriers/views.py

@@ -5,7 +5,7 @@
 
 from dateutil.parser import parse
 from django.db import transaction
-from django.db.models import Case, CharField, F, Value, When
+from django.db.models import Case, CharField, F, Prefetch, Value, When
 from django.http import StreamingHttpResponse
 from django.shortcuts import get_object_or_404
 from django.utils import timezone
@@ -18,6 +18,7 @@
 from rest_framework.viewsets import GenericViewSet, ModelViewSet
 from simple_history.utils import bulk_create_with_history
 
+from api.barriers import barrier_cache
 from api.barriers.exceptions import PublicBarrierPublishException
 from api.barriers.helpers import get_or_create_public_barrier
 from api.barriers.models import (
@@ -266,9 +267,7 @@ class BarrierList(generics.ListAPIView):
         Barrier.barriers.all()
         .select_related("priority")
         .prefetch_related(
-            "tags",
-            "organisations",
-            "progress_updates",
+            "tags", "organisations", "progress_updates", "valuation_assessments"
         )
     )
     serializer_class = BarrierListSerializer
@@ -422,14 +421,44 @@ class BarrierDetail(TeamMemberModelMixin, generics.RetrieveUpdateAPIView):
     lookup_field = "pk"
     queryset = (
         Barrier.barriers.all()
-        .select_related("priority")
+        .select_related(
+            "priority",
+            "created_by",
+            "modified_by",
+            "proposed_estimated_resolution_date_user",
+        )
         .prefetch_related(
+            "tags",
+            Prefetch(
+                "barrier_team",
+                queryset=TeamMember.objects.select_related("user")
+                .filter(role="Owner")
+                .all(),
+            ),
+            "organisations",
+            Prefetch(
+                "progress_updates",
+                queryset=BarrierProgressUpdate.objects.order_by("-created_on").all(),
+            ),
+            Prefetch(
+                "programme_fund_progress_updates",
+                queryset=ProgrammeFundProgressUpdate.objects.select_related(
+                    "created_by", "modified_by"
+                )
+                .order_by("-created_on")
+                .all(),
+            ),
             "barrier_commodities",
+            "public_barrier",
             "categories",
             "economic_assessments",
             "valuation_assessments",
-            "organisations",
-            "tags",
+            Prefetch(
+                "next_steps_items",
+                queryset=BarrierNextStepItem.objects.filter(
+                    status="IN_PROGRESS"
+                ).order_by("-completion_date"),
+            ),
         )
     )
 
@@ -447,6 +476,10 @@ def perform_update(self, serializer):
         self.update_contributors(barrier)
         barrier = serializer.save(modified_by=self.request.user)
         self.update_metadata_for_proposed_estimated_date(barrier)
+        lookup_url_kwarg = self.lookup_url_kwarg or self.lookup_field
+        pk = self.kwargs[lookup_url_kwarg]
+
+        barrier_cache.delete(pk)
 
     def update_metadata_for_proposed_estimated_date(self, barrier):
         # get patched data from request
@@ -458,6 +491,24 @@ def update_metadata_for_proposed_estimated_date(self, barrier):
             barrier.proposed_estimated_resolution_date_created = datetime.now()
             barrier.save()
 
+    def retrieve(self, request, *args, **kwargs):
+        lookup_url_kwarg = self.lookup_url_kwarg or self.lookup_field
+        try:
+            pk = self.kwargs[lookup_url_kwarg]
+        except KeyError:
+            """If view with `code` lookup (throws KeyError), don't cache"""
+            return super().retrieve(request, *args, **kwargs)
+
+        data = barrier_cache.get(pk)
+        if data:
+            return Response(data)
+
+        response = super().retrieve(request, *args, **kwargs)
+
+        barrier_cache.set(pk, response.data)
+
+        return response
+
 
 class BarrierFullHistory(generics.GenericAPIView):
     """
@@ -885,6 +936,9 @@ def create(self, request, *args, **kwargs):
         serializer.is_valid(raise_exception=True)
         self.perform_create(serializer, request.user)
         headers = self.get_success_headers(serializer.data)
+
+        barrier_cache.delete(serializer.data["barrier"])
+
         return Response(
             serializer.data, status=status.HTTP_201_CREATED, headers=headers
         )

api/metadata/utils.py

@@ -237,7 +237,7 @@ def get_trading_bloc_overseas_regions(trading_bloc_code):
 
 def get_wto_committee_groups():
     committee_groups = []
-    for group in wto_models.WTOCommitteeGroup.objects.all():
+    for group in wto_models.WTOCommitteeGroup.objects.prefetch_related("committees"):
         committee_groups.append(
             {
                 "id": str(group.id),