Optimize stats page performance

Gemfile

@@ -77,4 +77,5 @@ group :development do
   gem 'database_consistency', require: false
   gem 'foreman'
   gem 'rubocop-rails', require: false
+  gem 'bullet'
 end

Gemfile.lock

@@ -113,6 +113,9 @@ GEM
     brakeman (7.0.2)
       racc
     builder (3.3.0)
+    bullet (8.0.8)
+      activesupport (>= 3.0.0)
+      uniform_notifier (~> 1.11)
     bundler-audit (0.9.2)
       bundler (>= 1.2.0, < 3)
       thor (~> 1.0)
@@ -486,6 +489,7 @@ GEM
     unicode-display_width (3.1.4)
       unicode-emoji (~> 4.0, >= 4.0.4)
     unicode-emoji (4.0.4)
+    uniform_notifier (1.17.0)
     uri (1.0.3)
     useragent (0.16.11)
     warden (1.2.9)
@@ -519,6 +523,7 @@ DEPENDENCIES
   aws-sdk-s3 (~> 1.177.0)
   bootsnap
   brakeman
+  bullet
   bundler-audit
   capybara
   chartkick

app/controllers/stats_controller.rb

@@ -5,10 +5,30 @@ class StatsController < ApplicationController
   before_action :authenticate_active_user!, only: %i[update update_all]
 
   def index
-    @stats = current_user.stats.group_by(&:year).transform_values { |stats| stats.sort_by(&:updated_at).reverse }.sort.reverse
-    @points_total = current_user.tracked_points.count
-    @points_reverse_geocoded = current_user.total_reverse_geocoded_points
-    @points_reverse_geocoded_without_data = current_user.total_reverse_geocoded_points_without_data
+    @stats = current_user.stats.group_by(&:year).transform_values do |stats|
+      stats.sort_by(&:updated_at).reverse
+    end.sort.reverse
+
+    # Single aggregated query to replace 3 separate COUNT queries
+    result = current_user.tracked_points.connection.execute(<<~SQL.squish)
+      SELECT#{' '}
+        COUNT(*) as total,
+        COUNT(reverse_geocoded_at) as geocoded,
+        COUNT(CASE WHEN geodata = '{}' THEN 1 END) as without_data
+      FROM points#{' '}
+      WHERE user_id = #{current_user.id}
+    SQL
+
+    row = result.first
+    @points_total = row['total'].to_i
+    @points_reverse_geocoded = row['geocoded'].to_i
+    @points_reverse_geocoded_without_data = row['without_data'].to_i
+
+    # Precompute year distance data to avoid N+1 queries in view
+    @year_distances = {}
+    @stats.each do |year, _stats|
+      @year_distances[year] = Stat.year_distance(year, current_user)
+    end
   end
 
   def show

app/jobs/trips/calculate_all_job.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class Trips::CalculateAllJob < ApplicationJob
-  queue_as :default
+  queue_as :trips
 
   def perform(trip_id, distance_unit = 'km')
     Trips::CalculatePathJob.perform_later(trip_id)

app/jobs/trips/calculate_countries_job.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class Trips::CalculateCountriesJob < ApplicationJob
-  queue_as :default
+  queue_as :trips
 
   def perform(trip_id, distance_unit)
     trip = Trip.find(trip_id)

app/jobs/trips/calculate_distance_job.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class Trips::CalculateDistanceJob < ApplicationJob
-  queue_as :default
+  queue_as :trips
 
   def perform(trip_id, distance_unit)
     trip = Trip.find(trip_id)

app/jobs/trips/calculate_path_job.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class Trips::CalculatePathJob < ApplicationJob
-  queue_as :default
+  queue_as :trips
 
   def perform(trip_id)
     trip = Trip.find(trip_id)

app/models/country.rb

@@ -12,6 +12,8 @@ class Country < ApplicationRecord
   end
 
   def self.names_to_iso_a2
-    pluck(:name, :iso_a2).to_h
+    Rails.cache.fetch('countries_names_to_iso_a2', expires_in: 1.day) do
+      pluck(:name, :iso_a2).to_h
+    end
   end
 end

app/views/stats/_year.html.erb

@@ -4,7 +4,7 @@
 </h2>
 <div class='my-10'>
   <%= column_chart(
-    Stat.year_distance(year, current_user),
+    @year_distances[year],
     height: '200px',
     suffix: " #{current_user.safe_settings.distance_unit}",
     xtitle: 'Days',

app/views/stats/index.html.erb

@@ -82,7 +82,7 @@
             </div>
           <% end %>
           <%= column_chart(
-            Stat.year_distance(year, current_user).map { |month_name, distance_meters|
+            @year_distances[year].map { |month_name, distance_meters|
               [month_name, Stat.convert_distance(distance_meters, current_user.safe_settings.distance_unit).round(2)]
             },
             height: '200px',

config/environments/development.rb

@@ -3,6 +3,15 @@
 require 'active_support/core_ext/integer/time'
 
 Rails.application.configure do
+  config.after_initialize do
+    Bullet.enable        = true
+    Bullet.alert         = true
+    Bullet.bullet_logger = true
+    Bullet.console       = true
+    Bullet.rails_logger  = true
+    Bullet.add_footer    = true
+  end
+
   # Settings specified here will take precedence over those in config/application.rb.
 
   # In the development environment your application's code is reloaded any time

config/environments/production.rb

@@ -29,7 +29,7 @@ Rails.application.configure do
   # config.assets.css_compressor = :sass
 
   # Do not fallback to assets pipeline if a precompiled asset is missed.
-  config.assets.compile = true
+  config.assets.compile = false
 
   config.assets.content_type = {
     geojson: 'application/geo+json'

config/environments/test.rb

@@ -8,6 +8,12 @@ require 'active_support/core_ext/integer/time'
 # and recreated between test runs. Don't rely on the data there!
 
 Rails.application.configure do
+  config.after_initialize do
+    Bullet.enable        = true
+    Bullet.bullet_logger = true
+    Bullet.raise         = true # raise an error if n+1 query occurs
+  end
+
   # Settings specified here will take precedence over those in config/application.rb.
 
   # While tests run files are not watched, reloading is not necessary.

config/sidekiq.yml

@@ -6,6 +6,7 @@
   - imports
   - exports
   - stats
+  - trips
   - tracks
   - reverse_geocoding
   - visit_suggesting