Reduce number of redundant SQL queries

src/pretix/base/services/stats.py

@@ -28,48 +28,51 @@ def tuplesum(tuples: Iterable[Tuple]) -> Tuple:
     return tuple(map(mysum, zip(*list(tuples))))
 
 
+def dictsum(*dicts) -> dict:
+    res = {}
+    keys = set()
+    for d in dicts:
+        keys |= set(d.keys())
+    for k in keys:
+        res[k] = (sum(d[k][0] for d in dicts if k in d), sum(d[k][1] for d in dicts if k in d))
+    return res
+
+
 def order_overview(event: Event) -> Tuple[List[Tuple[ItemCategory, List[Item]]], Dict[str, Tuple[Decimal, Decimal]]]:
     items = event.items.all().select_related(
         'category',  # for re-grouping
+    ).prefetch_related(
+        'variations'
     ).order_by('category__position', 'category_id', 'name')
 
-    num_total = {
-        (p['item'], p['variation']): (p['cnt'], p['price'])
-        for p in (OrderPosition.objects
-                  .filter(order__event=event,
-                          order__status__in=[Order.STATUS_PENDING, Order.STATUS_EXPIRED, Order.STATUS_PAID])
-                  .values('item', 'variation')
-                  .annotate(cnt=Count('id'), price=Sum('price')).order_by())
-    }
+    counters = OrderPosition.objects.filter(
+        order__event=event
+    ).values(
+        'item', 'variation', 'order__status'
+    ).annotate(cnt=Count('id'), price=Sum('price')).order_by()
+
     num_canceled = {
         (p['item'], p['variation']): (p['cnt'], p['price'])
-        for p in (OrderPosition.objects
-                  .filter(order__event=event, order__status=Order.STATUS_CANCELED)
-                  .values('item', 'variation')
-                  .annotate(cnt=Count('id'), price=Sum('price')).order_by())
+        for p in counters if p['order__status'] == Order.STATUS_CANCELED
     }
     num_refunded = {
         (p['item'], p['variation']): (p['cnt'], p['price'])
-        for p in (OrderPosition.objects
-                  .filter(order__event=event, order__status=Order.STATUS_REFUNDED)
-                  .values('item', 'variation')
-                  .annotate(cnt=Count('id'), price=Sum('price')).order_by())
-    }
-    num_pending = {
-        (p['item'], p['variation']): (p['cnt'], p['price'])
-        for p in (OrderPosition.objects
-                  .filter(order__event=event,
-                          order__status__in=(Order.STATUS_PENDING, Order.STATUS_EXPIRED))
-                  .values('item', 'variation')
-                  .annotate(cnt=Count('id'), price=Sum('price')).order_by())
+        for p in counters if p['order__status'] == Order.STATUS_REFUNDED
     }
     num_paid = {
         (p['item'], p['variation']): (p['cnt'], p['price'])
-        for p in (OrderPosition.objects
-                  .filter(order__event=event, order__status=Order.STATUS_PAID)
-                  .values('item', 'variation')
-                  .annotate(cnt=Count('id'), price=Sum('price')).order_by())
+        for p in counters if p['order__status'] == Order.STATUS_PAID
     }
+    num_s_pending = {
+        (p['item'], p['variation']): (p['cnt'], p['price'])
+        for p in counters if p['order__status'] == Order.STATUS_PENDING
+    }
+    num_expired = {
+        (p['item'], p['variation']): (p['cnt'], p['price'])
+        for p in counters if p['order__status'] == Order.STATUS_EXPIRED
+    }
+    num_pending = dictsum(num_s_pending, num_expired)
+    num_total = dictsum(num_pending, num_paid)
 
     for item in items:
         item.all_variations = list(item.variations.all())
@@ -120,41 +123,33 @@ def order_overview(event: Event) -> Tuple[List[Tuple[ItemCategory, List[Item]]],
     payment_cat_obj = DummyObject()
     payment_cat_obj.name = _('Payment method fees')
     payment_items = []
-    num_total = {
-        o['payment_provider']: (o['cnt'], o['payment_fee'])
-        for o in (Order.objects
-                  .filter(event=event)
-                  .values('payment_provider')
-                  .annotate(cnt=Count('id'), payment_fee=Sum('payment_fee')).order_by())
-    }
+
+    counters = event.orders.values('payment_provider', 'status').annotate(
+        cnt=Count('id'), payment_fee=Sum('payment_fee')
+    ).order_by()
+
     num_canceled = {
         o['payment_provider']: (o['cnt'], o['payment_fee'])
-        for o in (Order.objects
-                  .filter(event=event, status=Order.STATUS_CANCELED)
-                  .values('payment_provider')
-                  .annotate(cnt=Count('id'), payment_fee=Sum('payment_fee')).order_by())
+        for o in counters if o['status'] == Order.STATUS_CANCELED
     }
     num_refunded = {
         o['payment_provider']: (o['cnt'], o['payment_fee'])
-        for o in (Order.objects
-                  .filter(event=event, status=Order.STATUS_REFUNDED)
-                  .values('payment_provider')
-                  .annotate(cnt=Count('id'), payment_fee=Sum('payment_fee')).order_by())
+        for o in counters if o['status'] == Order.STATUS_REFUNDED
     }
-    num_pending = {
+    num_s_pending = {
         o['payment_provider']: (o['cnt'], o['payment_fee'])
-        for o in (Order.objects
-                  .filter(event=event, status__in=(Order.STATUS_PENDING, Order.STATUS_EXPIRED))
-                  .values('payment_provider')
-                  .annotate(cnt=Count('id'), payment_fee=Sum('payment_fee')).order_by())
+        for o in counters if o['status'] == Order.STATUS_PENDING
+    }
+    num_expired = {
+        o['payment_provider']: (o['cnt'], o['payment_fee'])
+        for o in counters if o['status'] == Order.STATUS_EXPIRED
     }
     num_paid = {
         o['payment_provider']: (o['cnt'], o['payment_fee'])
-        for o in (Order.objects
-                  .filter(event=event, status=Order.STATUS_PAID)
-                  .values('payment_provider')
-                  .annotate(cnt=Count('id'), payment_fee=Sum('payment_fee')).order_by())
+        for o in counters if o['status'] == Order.STATUS_PAID
     }
+    num_pending = dictsum(num_s_pending, num_expired)
+    num_total = dictsum(num_pending, num_paid)
 
     provider_names = {}
     responses = register_payment_providers.send(event)

src/pretix/base/settings.py

@@ -514,8 +514,15 @@ class SettingsSandbox:
         self._event.settings.set(self._convert_key(key), value)
 
 
-class GlobalSettingsObject:
+class GlobalSettingsObject():
+    data_dict = None
+
     def __init__(self):
-        self.settings = SettingsProxy(self, type=GlobalSetting)
-        self.setting_objects = GlobalSetting.objects
-        self.slug = '_global'
+        # This is a singleton-like object. Multiple objects can exist, but they share their state
+        if GlobalSettingsObject.data_dict:
+            self.__dict__ = GlobalSettingsObject.data_dict
+        else:
+            self.settings = SettingsProxy(self, type=GlobalSetting)
+            self.setting_objects = GlobalSetting.objects
+            self.slug = '_global'
+            GlobalSettingsObject.data_dict = self.__dict__

src/pretix/control/templates/pretixcontrol/items/quota.html

@@ -31,26 +31,16 @@
                     {% if quota.size == None %}{% trans "Infinite" %}{% else %}{{ quota.size }}{% endif %}
                 </div>
             </div>
-            <div class="row">
-                <div class="col-xs-9">{% trans "Paid orders" %}</div>
-                <div class="col-xs-3 text-right"> – {{ quota.count_paid_orders }}</div>
-            </div>
-            <div class="row">
-                <div class="col-xs-9">{% trans "Pending orders" %}</div>
-                <div class="col-xs-3 text-right"> – {{ quota.count_pending_orders }}</div>
-            </div>
-            <div class="row">
-                <div class="col-xs-9">{% trans "Vouchers" %}</div>
-                <div class="col-xs-3 text-right"> – {{ quota.count_blocking_vouchers }}</div>
-            </div>
-            <div class="row">
-                <div class="col-xs-9">{% trans "Current user's carts" %}</div>
-                <div class="col-xs-3 text-right"> – {{ quota.count_in_cart }}</div>
-            </div>
+            {% for row in quota_table_rows %}
+                <div class="row">
+                    <div class="col-xs-9">{{ row.label }}</div>
+                    <div class="col-xs-3 text-right"> – {{ row.value }}</div>
+                </div>
+            {% endfor %}
             <div class="row">
                 <div class="col-xs-9"><strong>{% trans "Current availability" %}</strong></div>
                 <div class="col-xs-3 text-right">
-                    {% if quota.size == None %}{% trans "Infinite" %}{% else %}{{ quota.availability.1 }}{% endif %}
+                    {% if quota.size == None %}{% trans "Infinite" %}{% else %}{{ avail.1 }}{% endif %}
                 </div>
             </div>
         </div>

src/pretix/control/views/item.py

@@ -330,8 +330,8 @@ class QuestionMixin:
             can_order=False, can_delete=True, extra=0
         )
         return formsetclass(self.request.POST if self.request.method == "POST" else None,
-                            queryset=(QuestionOption.objects.filter(question=self.get_object())
-                                      if self.get_object() else QuestionOption.objects.none()),
+                            queryset=(QuestionOption.objects.filter(question=self.object)
+                                      if self.object else QuestionOption.objects.none()),
                             event=self.request.event)
 
     def save_formset(self, obj):
@@ -423,8 +423,9 @@ class QuestionView(EventPermissionRequiredMixin, QuestionMixin, ChartContainingV
     def get_context_data(self, **kwargs):
         ctx = super().get_context_data()
         ctx['items'] = self.object.items.all()
-        ctx['stats'] = self.get_answer_statistics()
-        ctx['stats_json'] = json.dumps(self.get_answer_statistics())
+        stats = self.get_answer_statistics()
+        ctx['stats'] = stats
+        ctx['stats_json'] = json.dumps(stats)
         return ctx
 
     def get_object(self, queryset=None) -> Question:
@@ -599,6 +600,10 @@ class QuotaView(ChartContainingView, DetailView):
 
     def get_context_data(self, *args, **kwargs):
         ctx = super().get_context_data()
+
+        avail = self.object.availability()
+        ctx['avail'] = avail
+
         data = [
             {
                 'label': ugettext('Paid orders'),
@@ -617,10 +622,12 @@ class QuotaView(ChartContainingView, DetailView):
                 'value': self.object.count_in_cart()
             }
         ]
+        ctx['quota_table_rows'] = list(data)
+
         if self.object.size is not None:
             data.append({
                 'label': ugettext('Current availability'),
-                'value': self.object.availability()[1]
+                'value': avail[1]
             })
         ctx['quota_chart_data'] = json.dumps(data)
         return ctx

src/pretix/control/views/main.py

@@ -20,8 +20,8 @@ class EventList(ListView):
     def get_queryset(self):
         return Event.objects.filter(
             permitted__id__exact=self.request.user.pk
-        ).prefetch_related(
-            "organizer",
+        ).select_related("organizer").prefetch_related(
+            "setting_objects", "organizer__setting_objects"
         )
 
 

src/pretix/presale/views/__init__.py

@@ -15,33 +15,24 @@ class CartMixin:
         """
         A list of this users cart position
         """
-        return list(CartPosition.objects.filter(
-            cart_id=self.request.session.session_key, event=self.request.event
-        ).order_by(
-            'item', 'variation'
-        ).select_related(
-            'item', 'variation'
-        ).prefetch_related(
-            'item__questions', 'answers'
-        ))
+        return list(get_cart(self.request))
 
     def get_cart(self, answers=False, queryset=None, payment_fee=None, payment_fee_tax_rate=None, downloads=False):
-        queryset = queryset or CartPosition.objects.filter(
-            cart_id=self.request.session.session_key, event=self.request.event
-        )
+        if queryset:
+            prefetch = []
+            if answers:
+                prefetch.append('item__questions')
+                prefetch.append('answers')
 
-        prefetch = []
-        if answers:
-            prefetch.append('item__questions')
-            prefetch.append('answers')
-
-        cartpos = queryset.order_by(
-            'item', 'variation'
-        ).select_related(
-            'item', 'variation'
-        ).prefetch_related(
-            *prefetch
-        )
+            cartpos = queryset.order_by(
+                'item', 'variation'
+            ).select_related(
+                'item', 'variation'
+            ).prefetch_related(
+                *prefetch
+            )
+        else:
+            cartpos = self.positions
 
         # Group items of the same variation
         # We do this by list manipulations instead of a GROUP BY query, as
@@ -101,6 +92,20 @@ class CartMixin:
         return payment_fee
 
 
+def get_cart(request):
+    if not hasattr(request, '_cart_cache'):
+        request._cart_cache = CartPosition.objects.filter(
+            cart_id=request.session.session_key, event=request.event
+        ).order_by(
+            'item', 'variation'
+        ).select_related(
+            'item', 'variation'
+        ).prefetch_related(
+            'item__questions', 'answers'
+        )
+    return request._cart_cache
+
+
 class EventViewMixin:
     def get_context_data(self, **kwargs):
         context = super().get_context_data(**kwargs)

src/pretix/presale/views/checkout.py

@@ -4,15 +4,17 @@ from django.shortcuts import redirect
 from django.utils.translation import ugettext_lazy as _
 from django.views.generic import View
 
+from pretix.base.models import CartPosition
 from pretix.multidomain.urlreverse import eventreverse
 from pretix.presale.checkoutflow import get_checkout_flow
-from pretix.presale.views import CartMixin
 
 
-class CheckoutView(CartMixin, View):
+class CheckoutView(View):
     def dispatch(self, request, *args, **kwargs):
         self.request = request
-        if not self.positions and "async_id" not in request.GET:
+        has_cart = CartPosition.objects.filter(
+            cart_id=self.request.session.session_key, event=self.request.event).exists()
+        if not has_cart and "async_id" not in request.GET:
             messages.error(request, _("Your cart is empty"))
             return redirect(eventreverse(self.request.event, 'presale:event.index'))
 

src/pretix/presale/views/event.py

@@ -1,9 +1,11 @@
 import sys
 
-from django.db.models import Count, Q
+from django.db.models import Count, Prefetch, Q
 from django.utils.timezone import now
 from django.views.generic import TemplateView
 
+from pretix.base.models import ItemVariation
+
 from . import CartMixin, EventViewMixin
 
 
@@ -21,48 +23,56 @@ def item_group_by_category(items):
     )
 
 
+def get_grouped_items(event):
+    items = event.items.all().filter(
+        Q(active=True)
+        & Q(Q(available_from__isnull=True) | Q(available_from__lte=now()))
+        & Q(Q(available_until__isnull=True) | Q(available_until__gte=now()))
+        & Q(hide_without_voucher=False)
+    ).select_related(
+        'category',  # for re-grouping
+    ).prefetch_related(
+        'quotas', 'variations__quotas', 'quotas__event',  # for .availability()
+        Prefetch('variations', to_attr='available_variations',
+                 queryset=ItemVariation.objects.filter(active=True, quotas__isnull=False).distinct()),
+    ).annotate(
+        quotac=Count('quotas'),
+        has_variations=Count('variations')
+    ).filter(
+        quotac__gt=0
+    ).order_by('category__position', 'category_id', 'position', 'name')
+    display_add_to_cart = False
+    for item in items:
+        if not item.has_variations:
+            item.cached_availability = list(item.check_quotas())
+            item.order_max = min(item.cached_availability[1]
+                                 if item.cached_availability[1] is not None else sys.maxsize,
+                                 int(event.settings.max_items_per_order))
+            item.price = item.default_price
+            display_add_to_cart = display_add_to_cart or item.order_max > 0
+        else:
+            for var in item.available_variations:
+                var.cached_availability = list(var.check_quotas())
+                var.order_max = min(var.cached_availability[1]
+                                    if var.cached_availability[1] is not None else sys.maxsize,
+                                    int(event.settings.max_items_per_order))
+                display_add_to_cart = display_add_to_cart or var.order_max > 0
+                var.price = var.default_price if var.default_price is not None else item.default_price
+            if len(item.available_variations) > 0:
+                item.min_price = min([v.price for v in item.available_variations])
+                item.max_price = max([v.price for v in item.available_variations])
+
+    items = [item for item in items if len(item.available_variations) > 0 or not item.has_variations]
+    return items, display_add_to_cart
+
+
 class EventIndex(EventViewMixin, CartMixin, TemplateView):
     template_name = "pretixpresale/event/index.html"
 
     def get_context_data(self, **kwargs):
         context = super().get_context_data(**kwargs)
         # Fetch all items
-        items = self.request.event.items.all().filter(
-            Q(active=True)
-            & Q(Q(available_from__isnull=True) | Q(available_from__lte=now()))
-            & Q(Q(available_until__isnull=True) | Q(available_until__gte=now()))
-            & Q(hide_without_voucher=False)
-        ).select_related(
-            'category',  # for re-grouping
-        ).prefetch_related(
-            'quotas', 'variations__quotas', 'quotas__event'  # for .availability()
-        ).annotate(quotac=Count('quotas')).filter(
-            quotac__gt=0
-        ).order_by('category__position', 'category_id', 'position', 'name')
-        display_add_to_cart = False
-        for item in items:
-            item.available_variations = list(item.variations.filter(active=True, quotas__isnull=False).distinct())
-            item.has_variations = item.variations.exists()
-            if not item.has_variations:
-                item.cached_availability = list(item.check_quotas())
-                item.order_max = min(item.cached_availability[1]
-                                     if item.cached_availability[1] is not None else sys.maxsize,
-                                     int(self.request.event.settings.max_items_per_order))
-                item.price = item.default_price
-                display_add_to_cart = display_add_to_cart or item.order_max > 0
-            else:
-                for var in item.available_variations:
-                    var.cached_availability = list(var.check_quotas())
-                    var.order_max = min(var.cached_availability[1]
-                                        if var.cached_availability[1] is not None else sys.maxsize,
-                                        int(self.request.event.settings.max_items_per_order))
-                    display_add_to_cart = display_add_to_cart or var.order_max > 0
-                    var.price = var.default_price if var.default_price is not None else item.default_price
-                if len(item.available_variations) > 0:
-                    item.min_price = min([v.price for v in item.available_variations])
-                    item.max_price = max([v.price for v in item.available_variations])
-
-        items = [item for item in items if len(item.available_variations) > 0 or not item.has_variations]
+        items, display_add_to_cart = get_grouped_items(self.request.event)
 
         # Regroup those by category
         context['items_by_category'] = item_group_by_category(items)

src/pretix/presale/views/order.py

@@ -34,7 +34,7 @@ class OrderDetailMixin:
     @cached_property
     def order(self):
         try:
-            order = Order.objects.get(event=self.request.event, code=self.kwargs['order'])
+            order = self.request.event.orders.get(code=self.kwargs['order'])
             if order.secret.lower() == self.kwargs['secret'].lower():
                 return order
             else: