Adding page loading time metrics

This change creates a new table where we simply log how much time a page
(url, controller, action, was it a turbo call?) took to render, so that
we can provide some statistics on the admin panel.

Author: dutow

app/controllers/application_controller.rb

@@ -1,11 +1,12 @@
 class ApplicationController < ActionController::Base
   allow_browser versions: :modern
-  
+
+  around_action :track_page_load_time
   rescue_from ActiveRecord::RecordNotFound, with: :render_404
   helper_method :current_user, :user_signed_in?, :current_admin?
   helper_method :activity_unread_count
   before_action :authorize_mini_profiler
-  
+
   private
 
   def render_404
@@ -43,4 +44,26 @@ def activity_unread_count
     return 0 unless current_user
     @activity_unread_count ||= Activity.where(user: current_user, hidden: false, read_at: nil).count
   end
+
+  def track_page_load_time
+    start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+    yield
+  ensure
+    begin
+      duration_ms = (Process.clock_gettime(Process::CLOCK_MONOTONIC) - start) * 1000.0
+
+      unless request.path == "/up" || !(request.format.html? || request.format.turbo_stream?)
+        PageLoadStat.insert({
+          url: request.path,
+          controller: controller_name,
+          action: action_name,
+          render_time: duration_ms.round(1),
+          is_turbo: turbo_frame_request? || request.format.turbo_stream?,
+          created_at: Time.current
+        })
+      end
+    rescue StandardError
+      # Never let logging break a request
+    end
+  end
 end

app/models/page_load_stat.rb

@@ -0,0 +1,2 @@
+class PageLoadStat < ApplicationRecord
+end

db/migrate/20260211120917_create_page_load_stats.rb

@@ -0,0 +1,15 @@
+class CreatePageLoadStats < ActiveRecord::Migration[8.0]
+  def change
+    create_table :page_load_stats do |t|
+      t.string :url, null: false
+      t.string :controller, null: false
+      t.string :action, null: false
+      t.float :render_time, null: false
+      t.boolean :is_turbo, default: false, null: false
+      t.datetime :created_at, null: false
+    end
+
+    add_index :page_load_stats, :created_at
+    add_index :page_load_stats, [:controller, :action]
+  end
+end

db/schema.rb

@@ -0,0 +1,35 @@
+require 'rails_helper'
+
+RSpec.describe PageLoadStat, type: :model do
+  it 'persists a record with all attributes' do
+    PageLoadStat.insert({
+      url: '/topics/1',
+      controller: 'topics',
+      action: 'show',
+      render_time: 42.5,
+      is_turbo: false,
+      created_at: Time.current
+    })
+
+    stat = PageLoadStat.last
+    expect(stat.url).to eq('/topics/1')
+    expect(stat.controller).to eq('topics')
+    expect(stat.action).to eq('show')
+    expect(stat.render_time).to be_within(0.01).of(42.5)
+    expect(stat.is_turbo).to eq(false)
+    expect(stat.created_at).to be_present
+  end
+
+  it 'stores turbo requests' do
+    PageLoadStat.insert({
+      url: '/topics/1',
+      controller: 'topics',
+      action: 'show',
+      render_time: 15.0,
+      is_turbo: true,
+      created_at: Time.current
+    })
+
+    expect(PageLoadStat.last.is_turbo).to eq(true)
+  end
+end