add some caching and preloading to user show page

app/helpers/domain/fa/users_helper.rb

@@ -12,6 +12,26 @@ module Domain::Fa::UsersHelper
   end
 
   def sanitized_fa_user_profile_html(html)
+    # try to preload all the FA usernames in the profile
+    maybe_url_names = Nokogiri::HTML(html).css("a").flat_map do |node|
+      href = URI.parse(node["href"])
+      right_host = href.host.nil? || href.host == "www.furaffinity.net"
+      right_path = href.path =~ /\/user\/.+/
+      if right_host && right_path
+        [href]
+      else
+        []
+      end
+    end.map do |href|
+      href.path.split("/")[2]&.downcase
+    end
+
+    preloaded_users = Domain::Fa::User.
+      where(url_name: maybe_url_names).
+      select(:state, :state_detail, :log_entry_detail, :url_name).
+      includes(:avatar).
+      index_by(&:url_name)
+
     raw Sanitize.fragment(
       html,
       elements: %w[br img b i span strong],
@@ -28,7 +48,7 @@ module Domain::Fa::UsersHelper
         href = URI.parse(node["href"])
         return unless href.host == nil || href.host == "www.furaffinity.net"
         return unless href.path =~ /\/user\/.+/
-        url_name = href.path.split("/")[2]
+        url_name = href.path.split("/")[2]&.downcase
         Sanitize.node!(node, {
           :elements => %w[a],
           :attributes => {
@@ -42,7 +62,8 @@ module Domain::Fa::UsersHelper
 
         whitelist = [node]
 
-        if (user = Domain::Fa::User.find_by(url_name: url_name))
+        user = preloaded_users[url_name] || Domain::Fa::User.find_by(url_name: url_name)
+        if user
           img = Nokogiri::XML::Node.new("img", node.document)
           img["class"] = "inline w-5"
           img["src"] = fa_user_avatar_path(user, thumb: "32-avatar")

app/models/domain/fa/user.rb

@@ -24,26 +24,26 @@ class Domain::Fa::User < ReduxApplicationRecord
          :scan_error, # user has been removed or otherwise, see state_detail
        ]
 
+  # Who this user follows (join table)
   has_many :follower_joins,
            class_name: "::Domain::Fa::Follow",
            foreign_key: :follower_id,
            inverse_of: :follower,
            dependent: :destroy
 
+  # Who this user follows (User model)
+  has_many :follows,
+           through: :follower_joins,
+           source: :followed
+
+  # Who follows this user (join table)
   has_many :followed_joins,
            class_name: "::Domain::Fa::Follow",
            foreign_key: :followed_id,
            inverse_of: :followed,
            dependent: :destroy
 
-  # Domain::Fa::User
-  # who this user follows
-  has_many :follows,
-           through: :follower_joins,
-           source: :followed
-
-  # Domain::Fa::User
-  # who follows this user
+  # Who follows this user (User model)
   has_many :followed_by,
            through: :followed_joins,
            source: :follower

app/views/domain/fa/users/_user.html.erb

@@ -27,13 +27,23 @@
       <span class="grow">Favorites</span>
       <span><%= number_with_delimiter(user.num_favorites, delimiter: ",") %></span>
     </div>
+    <div class='flex'>
+      <span class="grow">Following</span>
+      <span><%= number_with_delimiter(user.follower_joins.count, delimiter: ",") %></span>
+    </div>
+    <div class='flex'>
+      <span class="grow">Followed by</span>
+      <span><%= number_with_delimiter(user.followed_joins.count, delimiter: ",") %></span>
+    </div>
   </section>
   <%= render partial: "user_recent_posts_section", locals: { user: user } %>
   <section class='border-2 border-slate-300 rounded-md mb-2 overflow-clip'>
     <% if (profile_html = user.profile_html) %>
       <div class='text-lg border-b-2 border-b-slate-300 text-slate-600 p-1 italic'>Profile Description</div>
       <div class='p-2 bg-slate-800 text-slate-200'>
-        <%= sanitized_fa_user_profile_html(profile_html) %>
+        <% cache(user, expires_in: 12.hours) do %>
+          <%= sanitized_fa_user_profile_html(profile_html) %>
+        <% end %>
       </div>
     <% else %>
       <div>(No page description)</div>
@@ -42,15 +52,17 @@
   <section class='border-2 border-slate-300 rounded-md'>
     <div class='text-lg border-b-2 border-b-slate-300 text-slate-600 p-1 italic'>Similar Users</div>
     <div class='bg-slate-100'>
-      <% similar = similar_users_by_followed(user) %>
-      <% if similar %>
-        <% similar.each do |user| %>
-          <div class='flex flex-row py-1 px-2 border-b-2 last:border-b-0'>
-            <%= render "inline_link", user: user %>
-          </div>
+      <% cache(user.disco, expires_in: 12.hours) do %>
+        <% similar = similar_users_by_followed(user).includes(:avatar) %>
+        <% if similar %>
+          <% similar.each do |user| %>
+            <div class='flex flex-row py-1 px-2 border-b-2 last:border-b-0'>
+              <%= render "inline_link", user: user %>
+            </div>
+          <% end %>
+        <% else %>
+          <div class='p-2'>No similar users</div>
         <% end %>
-      <% else %>
-        <div class='p-2'>No similar users</div>
       <% end %>
     </div>
   </section>

config/environments/production.rb

@@ -58,7 +58,7 @@ Rails.application.configure do
   config.log_tags = [:request_id]
 
   # Use a different cache store in production.
-  # config.cache_store = :mem_cache_store
+  config.cache_store = :memory_store, { size: 64.megabytes }
 
   # Use a real queuing backend for Active Job (and separate queues per environment).
   # config.active_job.queue_adapter     = :resque

config/initializers/mini_profiler.rb

@@ -1,4 +1,5 @@
 if Rails.env.development? || Rails.env.staging?
   Rack::MiniProfiler.config.position = "top-right"
   Rack::MiniProfiler.config.disable_caching = false
+  Rack::MiniProfiler.config.skip_paths = [/\/blobs\/.+\/contents.jpg$/]
 end

config/initializers/pghero.rb

@@ -1 +1,2 @@
 PgHero.config["explain"] = "analyze"
+PgHero.config["explain_timeout_sec"] = 60