perf(backend): Remove N+1 on the parameters endpoint

backend/dpt_app/trails/models.py

@@ -68,8 +68,11 @@ class Meta:
     @property
     @admin.display(description=_("Maximum Game Duration"))
     def max_clock_duration(self):
-        """Get the maximum clock duration, in seconds"""
-        return Parameter.max_clock_duration(self)
+        """Get the maximum  clock duration in seconds at which the first parameter is zero"""
+        query = self.parameter.annotate(
+            dur_when_zero=-1 * (F('initial_value') + F('value')) / ((F('game__clock_speed') / F('game__clock_unit')) * F('rate')))
+
+        return query.aggregate(Min('dur_when_zero'))['dur_when_zero__min'] or 0
 
     @property
     @admin.display(description=_("Total Game Duration"))
@@ -195,14 +198,6 @@ class Meta:
         verbose_name=_("Game")
     )
 
-    @staticmethod
-    def max_clock_duration(game: Game):
-        """Get the maximum game clock duration in seconds at which the first parameter is zero"""
-        query = Parameter.objects.filter(game=game).annotate(
-            dur_when_zero=-1 * (F('initial_value') + F('value')) / ((F('game__clock_speed') / F('game__clock_unit')) * F('rate')))
-
-        return query.aggregate(Min('dur_when_zero'))['dur_when_zero__min'] or 0
-
     def value_at(self, clock_duration):
         """Get the parameter value at a specific game clock duration"""
         value = round((self.initial_value + self.value) + clock_duration

backend/dpt_app/trails/views.py

@@ -226,6 +226,12 @@ def get_bearer(request):
 
 
 def func_parameter_get(game, player):
+    # By retrieving the duration only once, then call `.value_at(dur)`
+    # on every parameter instead of `.current_value`, we only need a
+    # single SQL query for the duration instead of N, where N is the
+    # number of parameters.
+    dur = game.total_clock_duration
+
     response = []
     for parameter in game.parameter.all():
         response.append(
@@ -234,7 +240,7 @@ def func_parameter_get(game, player):
                 "id": parameter.name,
                 "attributes": {
                     "scope": parameter.scope,
-                    "value": parameter.current_value,
+                    "value": parameter.value_at(dur),
                     "rate": parameter.rate,
                     "min": parameter.min_value,
                     "max": parameter.max_value