Add cached fields to Item model for searching, but don't use them yet

This is the first part of a change to improve search performance, by
caching occupied zone IDs and supported body IDs onto the Item record
itself, instead of always doing joins with `SwfAsset`.

It's unfortunate, because part of the power of SQL is joins! But doing
joins with big tables, in ways that can't take advantage of indexes in
the same ways as we often want to, is… slow.

It's possible there's something I'm misunderstanding about SQL
optimization, and this _could_ be done with query optimization or
indexes instead of duplicating data like this? This complexity carries
the risk of data getting out of sync in unforeseen ways. But this is
what I know how to do, and it seems to be working, so! Okay!

app/models/item.rb

@@ -296,6 +296,12 @@ class Item < ApplicationRecord
     restricted_zones + occupied_zones
   end
 
+  def update_cached_fields
+    self.cached_occupied_zone_ids = occupied_zone_ids.sort.join(",")
+    self.cached_compatible_body_ids = compatible_body_ids.sort.join(",")
+    self.save!
+  end
+
   def species_support_ids
     @species_support_ids_array ||= read_attribute('species_support_ids').split(',').map(&:to_i) rescue nil
   end

app/models/parent_swf_asset_relationship.rb

@@ -5,6 +5,9 @@ class ParentSwfAssetRelationship < ApplicationRecord
   
   belongs_to :swf_asset
 
+  after_save :update_parent_cached_fields
+  after_destroy :update_parent_cached_fields
+  
   def item=(replacement)
     self.parent = replacement
   end
@@ -16,4 +19,8 @@ class ParentSwfAssetRelationship < ApplicationRecord
   def pet_state=(replacement)
     self.parent = replacement
   end
+
+  def update_parent_cached_fields
+    parent.try(:update_cached_fields)
+  end
 end

db/migrate/20241001052510_add_cached_fields_to_items.rb

@@ -0,0 +1,16 @@
+class AddCachedFieldsToItems < ActiveRecord::Migration[7.2]
+  def change
+    add_column :items, :cached_occupied_zone_ids, :string, null: false, default: ""
+    add_column :items, :cached_compatible_body_ids, :text, null: false, default: ""
+
+    reversible do |direction|
+      direction.up do
+        puts "Updating cached item fields for all items…"
+        Item.includes(:swf_assets).find_in_batches.with_index do |items, batch|
+          puts "Updating item batch ##{batch+1}…"
+          items.each(&:update_cached_fields)
+        end
+      end
+    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[7.2].define(version: 2024_09_28_022359) do
+ActiveRecord::Schema[7.2].define(version: 2024_10_01_052510) do
   create_table "alt_styles", charset: "utf8mb4", collation: "utf8mb4_unicode_520_ci", force: :cascade do |t|
     t.integer "species_id", null: false
     t.integer "color_id", null: false
@@ -137,6 +137,8 @@ ActiveRecord::Schema[7.2].define(version: 2024_09_28_022359) do
     t.text "description", size: :medium, null: false
     t.string "rarity", default: "", null: false
     t.integer "dyeworks_base_item_id"
+    t.string "cached_occupied_zone_ids", default: "", null: false
+    t.text "cached_compatible_body_ids", default: "", null: false
     t.index ["dyeworks_base_item_id"], name: "index_items_on_dyeworks_base_item_id"
     t.index ["modeling_status_hint", "created_at", "id"], name: "items_modeling_status_hint_and_created_at_and_id"
     t.index ["modeling_status_hint", "created_at"], name: "items_modeling_status_hint_and_created_at"
@@ -154,7 +156,7 @@ ActiveRecord::Schema[7.2].define(version: 2024_09_28_022359) do
   end
 
   create_table "modeling_logs", id: :integer, charset: "utf8mb4", collation: "utf8mb4_unicode_520_ci", force: :cascade do |t|
-    t.datetime "created_at", precision: nil, default: -> { "CURRENT_TIMESTAMP" }, null: false
+    t.datetime "created_at", precision: nil, default: -> { "current_timestamp()" }, null: false
     t.text "log_json", size: :long, null: false
     t.string "pet_name", limit: 128, null: false
   end