DEV: Add caching to the leaderboard page

app/controllers/discourse_gamification/gamification_leaderboard_controller.rb

@@ -5,6 +5,8 @@ class GamificationLeaderboardController < ::ApplicationController
     requires_plugin PLUGIN_NAME
 
     def respond
+      discourse_expires_in 1.minute
+
       default_leaderboard_id = GamificationLeaderboard.first.id
       params[:id] ||= default_leaderboard_id
       leaderboard = GamificationLeaderboard.find(params[:id])

app/models/discourse_gamification/gamification_leaderboard.rb

@@ -30,55 +30,95 @@ def get_period_date(period_symbol)
       end
     end
 
+    def self.get_cache_key(leaderboard, page, period, user_limit)
+      [
+        "leaderboard",
+        leaderboard.id,
+        page,
+        period&.strftime("%Y%m%d"),
+        user_limit,
+        leaderboard.included_groups_ids.present? ? leaderboard.included_groups_ids.join : nil,
+        leaderboard.excluded_groups_ids.present? ? leaderboard.excluded_groups_ids.join : nil,
+        leaderboard.from_date.present? ? leaderboard.from_date.strftime("%Y%m%d") : nil,
+        (
+          if (leaderboard.to_date != Date.today && !leaderboard.from_date.present?)
+            leaderboard.to_date.strftime("%Y%m%d")
+          else
+            nil
+          end
+        ),
+      ].compact.map(&:to_s).join(":")
+    end
+
     def self.scores_for(leaderboard_id, page: 0, for_user_id: false, period: nil, user_limit: nil)
       leaderboard = self.find(leaderboard_id)
       leaderboard.to_date ||= Date.today
 
       join_sql = "LEFT OUTER JOIN gamification_scores ON gamification_scores.user_id = users.id"
       sum_sql = "SUM(COALESCE(gamification_scores.score, 0)) as total_score"
 
-      users =
-        User
-          .joins(:primary_email)
-          .real
-          .where.not("user_emails.email LIKE '%@anonymized.invalid%'")
-          .where(staged: false)
-          .joins(join_sql)
-      users =
-        users.where(
-          "EXISTS (SELECT 1 FROM group_users AS gu WHERE group_id IN (?) and gu.user_id = users.id)",
-          leaderboard.included_groups_ids,
-        ) if leaderboard.included_groups_ids.present?
-      users =
-        users.where(
-          "NOT EXISTS (SELECT 1 FROM group_users AS gu WHERE group_id IN (?) and gu.user_id = users.id)",
-          leaderboard.excluded_groups_ids,
-        ) if leaderboard.excluded_groups_ids.present?
-      users =
-        users.where(
-          "gamification_scores.date BETWEEN ? AND ?",
-          leaderboard.from_date,
-          leaderboard.to_date,
-        ) if leaderboard.from_date.present?
-      # calculate scores up to to_date if just to_date is present
-      users =
-        users.where("gamification_scores.date <= ?", leaderboard.to_date) if leaderboard.to_date !=
-        Date.today && !leaderboard.from_date.present?
-      users = users.where("gamification_scores.date >= ?", period) if period.present?
-      users =
-        users
-          .select("users.id, users.name, users.username, users.uploaded_avatar_id, #{sum_sql}")
-          .group("users.id")
-          .order(total_score: :desc, id: :asc)
+      cache_key = get_cache_key(leaderboard, page, period, user_limit)
+
+      users = Discourse.cache.read(cache_key) # Shared w/ paged_users and user_position queries
+      paged_users = Discourse.cache.read("#{cache_key}:paged")
+      user_position = Discourse.cache.read("#{cache_key}:#{for_user_id}") if for_user_id
+
+      if !users
+        users =
+          User
+            .joins(:primary_email)
+            .real
+            .where.not("user_emails.email LIKE '%@anonymized.invalid%'")
+            .where(staged: false)
+            .joins(join_sql)
+        users =
+          users.where(
+            "EXISTS (SELECT 1 FROM group_users AS gu WHERE group_id IN (?) and gu.user_id = users.id)",
+            leaderboard.included_groups_ids,
+          ) if leaderboard.included_groups_ids.present?
+        users =
+          users.where(
+            "NOT EXISTS (SELECT 1 FROM group_users AS gu WHERE group_id IN (?) and gu.user_id = users.id)",
+            leaderboard.excluded_groups_ids,
+          ) if leaderboard.excluded_groups_ids.present?
+        users =
+          users.where(
+            "gamification_scores.date BETWEEN ? AND ?",
+            leaderboard.from_date,
+            leaderboard.to_date,
+          ) if leaderboard.from_date.present?
+        # calculate scores up to to_date if just to_date is present
+        users =
+          users.where(
+            "gamification_scores.date <= ?",
+            leaderboard.to_date,
+          ) if leaderboard.to_date != Date.today && !leaderboard.from_date.present?
+        users = users.where("gamification_scores.date >= ?", period) if period.present?
+        users =
+          users
+            .select("users.id, users.name, users.username, users.uploaded_avatar_id, #{sum_sql}")
+            .group("users.id")
+            .order(total_score: :desc, id: :asc)
+        Discourse.cache.write(cache_key, users, expires_in: 4.hours)
+      end
 
       if for_user_id
-        user = users.find_by(id: for_user_id)
-        index = users.index(user)
-        return { user: user, position: index ? index + 1 : nil }
+        if !user_position
+          user = users.find_by(id: for_user_id)
+          index = users.index(user)
+          user_position = { user: user, position: index ? index + 1 : nil }
+          Discourse.cache.write("#{cache_key}:#{for_user_id}", user_position, expires_in: 4.hours)
+        end
+        return user_position
+      end
+
+      if !paged_users
+        users = users.offset(PAGE_SIZE * page) if page > 0
+        users = users.limit(user_limit || PAGE_SIZE)
+        Discourse.cache.write("#{cache_key}:paged", users, expires_in: 4.hours)
       end
-      users = users.offset(PAGE_SIZE * page) if page > 0
-      users = users.limit(user_limit || PAGE_SIZE)
-      users
+
+      paged_users.present? ? paged_users : users
     end
   end
 end

spec/requests/gamification_leaderboard_controller_spec.rb

@@ -56,13 +56,43 @@
 
   describe "#respond" do
     it "returns users and their calculated scores" do
-      get "/leaderboard/#{leaderboard.id}.json"
-      expect(response.status).to eq(200)
-
-      data = response.parsed_body
-      expect(data["users"][0]["username"]).to eq(current_user.username)
-      expect(data["users"][0]["avatar_template"]).to eq(current_user.avatar_template)
-      expect(data["users"][0]["total_score"]).to eq(current_user.gamification_score)
+      freeze_time
+      initial_sql_queries_count =
+        track_sql_queries do
+          get "/leaderboard/#{leaderboard.id}.json"
+          expect(response.status).to eq(200)
+
+          data = response.parsed_body
+          expect(data["users"][0]["username"]).to eq(current_user.username)
+          expect(data["users"][0]["avatar_template"]).to eq(current_user.avatar_template)
+          expect(data["users"][0]["total_score"]).to eq(current_user.gamification_score)
+        end.length
+
+      freeze_time 1.minutes.from_now
+      new_sql_queries_count =
+        track_sql_queries do
+          get "/leaderboard/#{leaderboard.id}.json"
+          expect(response.status).to eq(200)
+
+          data = response.parsed_body
+          expect(data["users"][0]["username"]).to eq(current_user.username)
+          expect(data["users"][0]["avatar_template"]).to eq(current_user.avatar_template)
+          expect(data["users"][0]["total_score"]).to eq(current_user.gamification_score)
+        end.length
+      expect(new_sql_queries_count).to be < initial_sql_queries_count
+
+      freeze_time 6.hours.from_now
+      reset_sql_queries_count =
+        track_sql_queries do
+          get "/leaderboard/#{leaderboard.id}.json"
+          expect(response.status).to eq(200)
+
+          data = response.parsed_body
+          expect(data["users"][0]["username"]).to eq(current_user.username)
+          expect(data["users"][0]["avatar_template"]).to eq(current_user.avatar_template)
+          expect(data["users"][0]["total_score"]).to eq(current_user.gamification_score)
+        end.length
+      expect(reset_sql_queries_count).to eq(initial_sql_queries_count)
     end
 
     it "only returns users and scores for specified date range" do