Leaderboard performance low-hanging fruit (#344)

* Simplify leaderboard HTML template

* Some low-hanging fruit performance improvements and cleanup

accounts/models.py

@@ -117,6 +117,11 @@ def public_profile_url(self):
         if not self.invest_anonymously:
             return reverse("public_profile", args=(self.user.username,))
 
+    def get_total_earned(self):
+        investments = Investment.objects.filter_user_investments(user=self.user)
+        total_earned = sum(investment.generated_revenue() for investment in investments)
+        return total_earned
+
     @cache_using_pk
     def profile_context(self):
         context = {}
@@ -163,6 +168,8 @@ def profile_context(self):
                 generated_revenue_user += investment.generated_revenue()
             context["artists"][artist.id].total_earned += generated_revenue_user
             total_earned += generated_revenue_user
+
+        # TODO(lucas): Could refactor to use get_total_earned() instead
         context["total_earned"] = total_earned
 
         # Add percentage of return to context

campaign/managers.py

@@ -0,0 +1,8 @@
+from django.db import models
+
+
+class InvestmentManager(models.Manager):
+    def filter_user_investments(self, user):
+        return self.filter(
+            charge__customer__user=user, charge__paid=True, charge__refunded=False
+        )

campaign/models.py

@@ -12,6 +12,8 @@
 
 from pinax.stripe.models import Charge
 
+from campaign.managers import InvestmentManager
+
 
 class Project(models.Model):
 
@@ -254,6 +256,8 @@ class Investment(models.Model):
         default=1, help_text="The number of shares an investor made in a transaction"
     )
 
+    objects = InvestmentManager()
+
     def __str__(self):
         return "{num_shares} shares in {campaign} to {investor}".format(
             num_shares=self.num_shares,

campaign/views.py

@@ -5,48 +5,50 @@
 """
 
 from django.core.cache import cache
+from django.db.models import OuterRef, Exists
 from django.views.generic import TemplateView
 
 from accounts.models import UserProfile
+from campaign.models import Investment
 
 
 class LeaderboardView(TemplateView):
 
     template_name = "leaderboard/leaderboard.html"
 
-    def investor_context(self, investor, key_to_copy):
-        context = investor.profile_context()
-        context["amount"] = context[key_to_copy]
-        context.update(
-            {
-                "name": investor.get_display_name(),
-                "url": investor.public_profile_url(),
-                "avatar_url": investor.avatar_url(),
-            }
-        )
-        return context
+    @staticmethod
+    def investor_context(investor):
+        return {
+            "name": investor.get_display_name(),
+            "url": investor.public_profile_url(),
+            "avatar_url": investor.avatar_url(),
+            "amount": investor.get_total_earned(),
+        }
 
     # TODO(lucas): Review to improve performance
     # Warning: top_earned_investors absolutely will not scale, the view is meant
     # to be run occasionally (once a day) and then have the whole page cached
     def calculate_leaderboard(self):
-        # Top earned investors
         user_profiles = UserProfile.objects.filter(invest_anonymously=False)
+        investments = Investment.objects.filter_user_investments(user=OuterRef("pk"))
+        investors = user_profiles.annotate(has_invested=Exists(investments)).filter(
+            has_invested=True
+        )
+
+        # Top earned investors
         top_earned_investors = [
-            self.investor_context(user_profile, "total_earned")
-            for user_profile in user_profiles
+            self.investor_context(investor) for investor in investors
         ]
         top_earned_investors = list(
             filter(lambda context: context["amount"] > 0, top_earned_investors)
         )
         top_earned_investors = sorted(
             top_earned_investors, key=lambda context: context["amount"], reverse=True
         )[:20]
-
-        return {"top_earned_investors": top_earned_investors}
+        return top_earned_investors
 
     def get_context_data(self, **kwargs):
         context = super().get_context_data(**kwargs)
         leaderboard = cache.get_or_set("leaderboard", self.calculate_leaderboard)
-        context.update(leaderboard)
+        context["top_earned_investors"] = leaderboard
         return context

templates/leaderboard/leaderboard.html

@@ -11,7 +11,17 @@
 {% block content %}
     <h2>Top Investors</h2>
     <div class="center">
-        {% include "leaderboard/includes/list.html" with name='Investors' leaders=top_earned_investors %}
+        <div class="leaderboard">
+            {% for leader_context in top_earned_investors %}
+                <a href="{{ leader_context.url }}">
+                    <div class="leaderboard-padding button">
+                        <img class="profile-crop" src="{{ leader_context.avatar_url }}" alt="{{ leader_context.name }}" />
+                        <br/>
+                        <h4 class="chart-name">#{{ forloop.counter }}: {{ leader_context.name }}</h4>
+                        <h4 class="chart-amount">${{ leader_context.amount|notrail_floatformat:2|intcomma }}</h4>
+                    </div>
+                </a>
+            {% endfor %}
+        </div>
     </div>
-
 {% endblock %}