Add `MediaAttachment.combined_media_file_size` method (#35570)

app/lib/admin/metrics/dimension/space_usage_dimension.rb

@@ -40,7 +40,7 @@ class Admin::Metrics::Dimension::SpaceUsageDimension < Admin::Metrics::Dimension
 
   def media_size
     value = [
-      MediaAttachment.sum(Arel.sql('COALESCE(file_file_size, 0) + COALESCE(thumbnail_file_size, 0)')),
+      MediaAttachment.sum(MediaAttachment.combined_media_file_size),
       CustomEmoji.sum(:image_file_size),
       PreviewCard.sum(:image_file_size),
       Account.sum(Arel.sql('COALESCE(avatar_file_size, 0) + COALESCE(header_file_size, 0)')),

app/lib/admin/metrics/measure/instance_media_attachments_measure.rb

@@ -29,7 +29,7 @@ class Admin::Metrics::Measure::InstanceMediaAttachmentsMeasure < Admin::Metrics:
   def perform_total_query
     domain = params[:domain]
     domain = Instance.by_domain_and_subdomains(params[:domain]).select(:domain) if params[:include_subdomains]
-    MediaAttachment.joins(:account).merge(Account.where(domain: domain)).sum('COALESCE(file_file_size, 0) + COALESCE(thumbnail_file_size, 0)')
+    MediaAttachment.joins(:account).merge(Account.where(domain: domain)).sum(MediaAttachment.combined_media_file_size)
   end
 
   def perform_previous_total_query
@@ -44,7 +44,7 @@ class Admin::Metrics::Measure::InstanceMediaAttachmentsMeasure < Admin::Metrics:
     <<~SQL.squish
       SELECT axis.*, (
         WITH new_media_attachments AS (
-          SELECT COALESCE(media_attachments.file_file_size, 0) + COALESCE(media_attachments.thumbnail_file_size, 0) AS size
+          SELECT #{media_size_total} AS size
           FROM media_attachments
           INNER JOIN accounts ON accounts.id = media_attachments.account_id
           WHERE date_trunc('day', media_attachments.created_at)::date = axis.period
@@ -58,6 +58,10 @@ class Admin::Metrics::Measure::InstanceMediaAttachmentsMeasure < Admin::Metrics:
     SQL
   end
 
+  def media_size_total
+    MediaAttachment.combined_media_file_size.to_sql
+  end
+
   def params
     @params.permit(:domain, :include_subdomains)
   end

app/models/media_attachment.rb

@@ -298,6 +298,10 @@ class MediaAttachment < ApplicationRecord
       IMAGE_FILE_EXTENSIONS + VIDEO_FILE_EXTENSIONS + AUDIO_FILE_EXTENSIONS
     end
 
+    def combined_media_file_size
+      arel_table.coalesce(arel_table[:file_file_size], 0) + arel_table.coalesce(arel_table[:thumbnail_file_size], 0)
+    end
+
     private
 
     def file_styles(attachment)

lib/mastodon/cli/media.rb

@@ -313,9 +313,7 @@ module Mastodon::CLI
     end
 
     def combined_media_sum
-      Arel.sql(<<~SQL.squish)
-        COALESCE(file_file_size, 0) + COALESCE(thumbnail_file_size, 0)
-      SQL
+      MediaAttachment.combined_media_file_size
     end
 
     def preload_records_from_mixed_objects(objects)

spec/models/media_attachment_spec.rb

@@ -313,6 +313,12 @@ RSpec.describe MediaAttachment, :attachment_processing do
     end
   end
 
+  describe '.combined_media_file_size' do
+    subject { described_class.combined_media_file_size }
+
+    it { is_expected.to be_an(Arel::Nodes::Grouping) }
+  end
+
   private
 
   def media_metadata