(no-ticket) Optimize some redundant db queries in views

Change-Id: Ib9500d17e370cf361b616174bc85c4a9477c96c7

oioioi/clock/views.py

@@ -8,12 +8,19 @@
 from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 
+from oioioi.base.utils import request_cached
 from oioioi.base.utils.redirect import safe_redirect
 from oioioi.contests.models import Round
 from oioioi.status.registry import status_registry
 from oioioi.su.utils import is_real_superuser
 
 
+@request_cached
+def get_round_times(request):
+    contest = getattr(request, 'contest', None)
+    return [(contest.controller.get_round_times(request, round), round)
+              for round in Round.objects.filter(contest=contest)]
+
 @status_registry.register
 def get_times_status(request, response):
     """Extends the response dictionary with rounds times.
@@ -46,10 +53,7 @@ def get_times_status(request, response):
     current_rounds_times = None
 
     if timestamp and contest:
-        rtimes = [
-            (contest.controller.get_round_times(request, round), round)
-            for round in Round.objects.filter(contest=contest)
-        ]
+        rtimes = get_round_times(request)
         next_rounds_times = [
             (rt, round) for (rt, round) in rtimes if rt.is_future(timestamp)
         ]

oioioi/problems/processors.py

@@ -14,12 +14,10 @@ def dangling_problems_processor(request):
     if not is_contest_basicadmin(request):
         return {}
 
+    dangling_pis = ProblemInstance.objects.filter(contest=request.contest,
+            round__isnull=True)
+    count = dangling_pis.count()
     def generator():
-        dangling_pis = ProblemInstance.objects.filter(
-            contest=request.contest,
-            round__isnull=True,
-        )
-        count = dangling_pis.count()
         if not count:
             return ''
         elif count == 1:
@@ -53,11 +51,10 @@ def problems_need_rejudge_processor(request):
     if not is_contest_basicadmin(request):
         return {}
 
+    pis = ProblemInstance.objects.filter(contest=request.contest,
+            needs_rejudge=True)
+    count = pis.count()
     def generator():
-        pis = ProblemInstance.objects.filter(
-            contest=request.contest, needs_rejudge=True
-        )
-        count = pis.count()
         if not count:
             return ''
         else:

oioioi/questions/processors.py

@@ -2,7 +2,7 @@
 from django.utils.functional import lazy
 from django.utils.translation import ngettext
 
-from oioioi.base.utils import make_navbar_badge
+from oioioi.base.utils import make_navbar_badge, request_cached
 from oioioi.contests.utils import can_enter_contest, is_contest_basicadmin
 from oioioi.questions.utils import unanswered_questions
 from oioioi.questions.views import new_messages, visible_messages
@@ -29,6 +29,7 @@ def get_messages(request, response):
     return response
 
 
+@request_cached
 def navbar_messages_generator(request):
     if request.contest is None:
         return {}

oioioi/statistics/utils.py

@@ -1,5 +1,6 @@
 from django.template.loader import render_to_string
 
+from oioioi.base.utils import request_cached
 from oioioi.base.permissions import make_request_condition
 from oioioi.programs.controllers import ProgrammingContestController
 
@@ -30,6 +31,7 @@ def render_head(requirements):
 
 
 @make_request_condition
+@request_cached
 def any_statistics_avaiable(request):
     controller = request.contest.controller
     if not isinstance(controller, ProgrammingContestController):
@@ -38,5 +40,6 @@ def any_statistics_avaiable(request):
 
 
 @make_request_condition
+@request_cached
 def can_see_stats(request):
     return request.contest.controller.can_see_stats(request)