Fewer db requests on bda views.

bda.views.etat_places
- Use select_related on spectacles_set,  avoid query issue for each spectacle.
- `slots__sum` is computed in view, instead of a query.
- Cleaner code (and avoid useless computations).

bda.views.places
- Add select_related on places, avoid query issue for each spectacle.

bda.views.inscription
- 1 query for spectacle field choices, instead of (#forms in formset *
  #spectacles)
- Delete BaseBdaFormSet. The validation was redundant with
  `unique_together` of ChoixSpectacle model.

bda/forms.py

@@ -5,33 +5,10 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 from django import forms
-from django.forms.models import BaseInlineFormSet
 from django.utils import timezone
 from bda.models import Attribution, Spectacle
 
 
-class BaseBdaFormSet(BaseInlineFormSet):
-    def clean(self):
-        """Checks that no two articles have the same title."""
-        super(BaseBdaFormSet, self).clean()
-        if any(self.errors):
-            # Don't bother validating the formset unless each form is valid on
-            # its own
-            return
-        spectacles = []
-        for i in range(0, self.total_form_count()):
-            form = self.forms[i]
-            if not form.cleaned_data:
-                continue
-            spectacle = form.cleaned_data['spectacle']
-            delete = form.cleaned_data['DELETE']
-            if not delete and spectacle in spectacles:
-                raise forms.ValidationError(
-                    "Vous ne pouvez pas vous inscrire deux fois pour le "
-                    "même spectacle.")
-            spectacles.append(spectacle)
-
-
 class TokenForm(forms.Form):
     token = forms.CharField(widget=forms.widgets.Textarea())
 

bda/views.py

@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 
+from functools import partial
 import random
 import hashlib
 import time
@@ -11,9 +12,9 @@ from custommail.shortcuts import (
 from django.shortcuts import render, get_object_or_404
 from django.contrib.auth.decorators import login_required
 from django.contrib import messages
-from django.db import models, transaction
+from django.db import transaction
 from django.core import serializers
-from django.db.models import Count, Q, Sum
+from django.db.models import Count, Q
 from django.forms.models import inlineformset_factory
 from django.http import (
     HttpResponseBadRequest, HttpResponseRedirect, JsonResponse
@@ -29,8 +30,7 @@ from bda.models import (
 )
 from bda.algorithm import Algorithm
 from bda.forms import (
-    BaseBdaFormSet, TokenForm, ResellForm, AnnulForm, InscriptionReventeForm,
+    TokenForm, ResellForm, AnnulForm, InscriptionReventeForm, SoldForm,
-    SoldForm
 )
 
 
@@ -44,39 +44,44 @@ def etat_places(request, tirage_id):
     Et le total de toutes les demandes
     """
     tirage = get_object_or_404(Tirage, id=tirage_id)
-    spectacles1 = ChoixSpectacle.objects \
+
-        .filter(spectacle__tirage=tirage) \
+    spectacles = tirage.spectacle_set.select_related('location')
-        .filter(double_choice="1") \
+    spectacles_dict = {}  # index of spectacle by id
-        .all() \
+
-        .values('spectacle', 'spectacle__title') \
-        .annotate(total=models.Count('spectacle'))
-    spectacles2 = ChoixSpectacle.objects \
-        .filter(spectacle__tirage=tirage) \
-        .exclude(double_choice="1") \
-        .all() \
-        .values('spectacle', 'spectacle__title') \
-        .annotate(total=models.Count('spectacle'))
-    spectacles = tirage.spectacle_set.all()
-    spectacles_dict = {}
-    total = 0
     for spectacle in spectacles:
-        spectacle.total = 0
+        spectacle.total = 0  # init total requests
-        spectacle.ratio = 0.0
         spectacles_dict[spectacle.id] = spectacle
-    for spectacle in spectacles1:
+
-        spectacles_dict[spectacle["spectacle"]].total += spectacle["total"]
+    choices = (
-        spectacles_dict[spectacle["spectacle"]].ratio = \
+        ChoixSpectacle.objects
-            spectacles_dict[spectacle["spectacle"]].total / \
+        .filter(spectacle__in=spectacles)
-            spectacles_dict[spectacle["spectacle"]].slots
+        .values('spectacle')
-        total += spectacle["total"]
+        .annotate(total=Count('spectacle'))
-    for spectacle in spectacles2:
+    )
-        spectacles_dict[spectacle["spectacle"]].total += 2*spectacle["total"]
+
-        spectacles_dict[spectacle["spectacle"]].ratio = \
+    # choices *by spectacles* whose only 1 place is requested
-            spectacles_dict[spectacle["spectacle"]].total / \
+    choices1 = choices.filter(double_choice="1")
-            spectacles_dict[spectacle["spectacle"]].slots
+    # choices *by spectacles* whose 2 places is requested
-        total += 2*spectacle["total"]
+    choices2 = choices.exclude(double_choice="1")
+
+    for spectacle in choices1:
+        pk = spectacle['spectacle']
+        spectacles_dict[pk].total += spectacle['total']
+    for spectacle in choices2:
+        pk = spectacle['spectacle']
+        spectacles_dict[pk].total += 2*spectacle['total']
+
+    # here, each spectacle.total contains the number of requests
+
+    slots = 0  # proposed slots
+    total = 0  # requests
+    for spectacle in spectacles:
+        slots += spectacle.slots
+        total += spectacle.total
+        spectacle.ratio = spectacle.total / spectacle.slots
+
     context = {
-        "proposed": tirage.spectacle_set.aggregate(Sum('slots'))['slots__sum'],
+        "proposed": slots,
         "spectacles": spectacles,
         "total": total,
         'tirage': tirage
@@ -94,11 +99,16 @@ def _hash_queryset(queryset):
 @cof_required
 def places(request, tirage_id):
     tirage = get_object_or_404(Tirage, id=tirage_id)
-    participant, created = Participant.objects.get_or_create(
+    participant, _ = (
-        user=request.user, tirage=tirage)
+        Participant.objects
-    places = participant.attribution_set.order_by(
+        .get_or_create(user=request.user, tirage=tirage)
-        "spectacle__date", "spectacle").all()
+    )
-    total = sum([place.spectacle.price for place in places])
+    places = (
+        participant.attribution_set
+        .order_by("spectacle__date", "spectacle")
+        .select_related("spectacle", "spectacle__location")
+    )
+    total = sum(place.spectacle.price for place in places)
     filtered_places = []
     places_dict = {}
     spectacles = []
@@ -148,33 +158,62 @@ def inscription(request, tirage_id):
         return render(request, 'bda/resume-inscription-tirage.html', {})
     if timezone.now() > tirage.fermeture:
         # Le tirage est fermé.
-        participant, created = Participant.objects.get_or_create(
+        participant, _ = (
-            user=request.user, tirage=tirage)
+            Participant.objects
-        choices = participant.choixspectacle_set.order_by("priority").all()
+            .get_or_create(user=request.user, tirage=tirage)
+        )
+        choices = participant.choixspectacle_set.order_by("priority")
         messages.error(request,
                        " C'est fini : tirage au sort dans la journée !")
         return render(request, "bda/resume-inscription-tirage.html",
                       {"choices": choices})
 
-    def formfield_callback(f, **kwargs):
+    def force_for(f, to_choices=None, **kwargs):
+        """Overrides choices for ModelChoiceField.
+
+        Args:
+            f (models.Field): To render as forms.Field
+            to_choices (dict): If a key `f.name` exists, f._choices is set to
+                its value.
+
         """
-        Fonction utilisée par inlineformset_factory ci dessous.
+        formfield = f.formfield(**kwargs)
-        Restreint les spectacles proposés aux spectacles du bo tirage.
+        if to_choices:
-        """
+            if f.name in to_choices:
-        if f.name == "spectacle":
+                choices = [('', '---------')] + to_choices[f.name]
-            kwargs['queryset'] = tirage.spectacle_set
+                formfield._choices = choices
-        return f.formfield(**kwargs)
+        return formfield
+
+    # Restrict spectacles choices to spectacles for this tirage.
+    spectacles = (
+        tirage.spectacle_set
+        .select_related('location')
+    )
+    spectacles_field_choices = [(sp.pk, str(sp)) for sp in spectacles]
+
+    # Allow for spectacle choices to be set once for all.
+    # Form display use 1 request instead of (#forms of formset * #spectacles).
+    # FIXME: Validation still generates too much requests...
+    formfield_callback = partial(
+        force_for,
+        to_choices={
+            'spectacle': spectacles_field_choices,
+        },
+    )
     BdaFormSet = inlineformset_factory(
         Participant,
         ChoixSpectacle,
         fields=("spectacle", "double_choice", "priority"),
-        formset=BaseBdaFormSet,
+        formfield_callback=formfield_callback,
-        formfield_callback=formfield_callback)
+    )
-    participant, created = Participant.objects.get_or_create(
+    participant, _ = (
-        user=request.user, tirage=tirage)
+        Participant.objects
+        .get_or_create(user=request.user, tirage=tirage)
+    )
     success = False
     stateerror = False
     if request.method == "POST":
+        # use *this* queryset
         dbstate = _hash_queryset(participant.choixspectacle_set.all())
         if "dbstate" in request.POST and dbstate != request.POST["dbstate"]:
             stateerror = True
@@ -187,9 +226,14 @@ def inscription(request, tirage_id):
                 formset = BdaFormSet(instance=participant)
     else:
         formset = BdaFormSet(instance=participant)
+    # use *this* queryset
     dbstate = _hash_queryset(participant.choixspectacle_set.all())
     total_price = 0
-    for choice in participant.choixspectacle_set.all():
+    choices = (
+        participant.choixspectacle_set
+        .select_related('spectacle')
+    )
+    for choice in choices:
         total_price += choice.spectacle.price
         if choice.double:
             total_price += choice.spectacle.price