cache aggregated word counts on worldbuilding pages

Author: drusepth

app/jobs/cache_sum_attribute_word_count_job.rb

@@ -0,0 +1,19 @@
+class CacheSumAttributeWordCountJob < ApplicationJob
+  queue_as :cache
+
+  def perform(*args)
+    entity_type = args.shift
+    entity_id   = args.shift
+
+    entity = entity_type.constantize.find_by(id: entity_id)
+    sum_attribute_word_count = Attribute.where(entity_type: entity_type, entity_id: entity_id).sum(:word_count_cache)
+
+    update = entity.word_count_updates.find_or_initialize_by(
+      for_date: DateTime.current,
+    )
+    update.word_count = sum_attribute_word_count
+    update.user_id  ||= entity.user_id
+
+    update.save!
+  end
+end

app/models/concerns/is_content_page.rb

@@ -18,6 +18,11 @@ module IsContentPage
     has_many :timeline_events,             through: :timeline_event_entities
     has_many :timelines, -> { distinct },  through: :timeline_events
 
+    has_many :word_count_updates, as: :entity, dependent: :destroy
+    def latest_word_count_cache
+      word_count_updates.order('for_date DESC').limit(1).first.try(:word_count) ||  0
+    end
+
     scope :unarchived, -> { where(archived_at: nil) }
     def archive!
       update!(archived_at: DateTime.now)

app/models/page_data/attribute.rb

@@ -20,7 +20,13 @@ class Attribute < ApplicationRecord
   end
 
   after_commit do
-    CacheAttributeWordCountJob.perform_later(self.id) if saved_changes.key?('value')
+    if saved_changes.key?('value')
+      # Cache the updated word count on this attribute
+      CacheAttributeWordCountJob.perform_later(self.id)
+
+      # Cache the updated word count on the page this attribute belongs to
+      CacheSumAttributeWordCountJob.perform_later(self.entity_type, self.entity_id)
+    end
   end
 
   after_save do

app/models/word_count_update.rb

@@ -0,0 +1,4 @@
+class WordCountUpdate < ApplicationRecord
+  belongs_to :user
+  belongs_to :entity, polymorphic: true
+end

db/migrate/20211007234707_create_word_count_updates.rb

@@ -0,0 +1,12 @@
+class CreateWordCountUpdates < ActiveRecord::Migration[6.0]
+  def change
+    create_table :word_count_updates do |t|
+      t.references :user, null: false, foreign_key: true
+      t.references :entity, polymorphic: true, null: false
+      t.integer :word_count
+      t.date :for_date
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_10_07_215520) do
+ActiveRecord::Schema.define(version: 2021_10_07_234707) do
 
   create_table "active_storage_attachments", force: :cascade do |t|
     t.string "name", null: false
@@ -3637,6 +3637,18 @@
     t.integer "habitat_id"
   end
 
+  create_table "word_count_updates", force: :cascade do |t|
+    t.integer "user_id", null: false
+    t.string "entity_type", null: false
+    t.integer "entity_id", null: false
+    t.integer "word_count"
+    t.date "for_date"
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+    t.index ["entity_type", "entity_id"], name: "index_word_count_updates_on_entity_type_and_entity_id"
+    t.index ["user_id"], name: "index_word_count_updates_on_user_id"
+  end
+
   add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
   add_foreign_key "api_keys", "users"
   add_foreign_key "api_requests", "application_integrations"
@@ -4048,4 +4060,5 @@
   add_foreign_key "vehicles", "users"
   add_foreign_key "votes", "users"
   add_foreign_key "votes", "votables"
+  add_foreign_key "word_count_updates", "users"
 end

lib/tasks/backfill.rake

@@ -1,7 +1,7 @@
 namespace :backfill do
   desc "Backfill cached word counts on all attributes"
   task attribute_word_count_caches: :environment do
-    Attribute.where(cached_word_count: nil).find_each do |attribute|
+    Attribute.where(word_count_cache: nil).where.not(value: ["", " ", ".", nil]).find_each do |attribute|
       word_count = WordCountAnalyzer::Counter.new(
         ellipsis:          'no_special_treatment',
         hyperlink:         'count_as_one',

test/fixtures/word_count_updates.yml

@@ -0,0 +1,15 @@
+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+one:
+  user: one
+  entity: one
+  entity_type: Entity
+  word_count: 1
+  for_date: 2021-10-07
+
+two:
+  user: two
+  entity: two
+  entity_type: Entity
+  word_count: 1
+  for_date: 2021-10-07

test/models/word_count_update_test.rb

@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class WordCountUpdateTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end