posts: use storage manager to backup files.

* Perform backups synchronously inside `distribute_files` instead of
  asynchronously in `queue_backup`. Asynchronous backups assumed that
  files are stored on the local filesystem, which isn't true in general.

* Remove obsolete backup service classes.

app/models/post.rb

@@ -29,7 +29,6 @@ class Post < ApplicationRecord
   before_save :set_tag_counts
   before_save :set_pool_category_pseudo_tags
   before_create :autoban
-  after_save :queue_backup, if: :md5_changed?
   after_save :create_version
   after_save :update_parent_on_save
   after_save :apply_post_metatags
@@ -134,6 +133,10 @@ class Post < ApplicationRecord
       storage_manager.store_file(file, self, :original)
       storage_manager.store_file(sample_file, self, :large) if sample_file.present?
       storage_manager.store_file(preview_file, self, :preview) if preview_file.present?
+
+      backup_storage_manager.store_file(file, self, :original)
+      backup_storage_manager.store_file(sample_file, self, :large) if sample_file.present?
+      backup_storage_manager.store_file(preview_file, self, :preview) if preview_file.present?
     end
 
     def file_path_prefix
@@ -168,6 +171,10 @@ class Post < ApplicationRecord
       "#{file_path_prefix}#{md5}.#{file_ext}"
     end
 
+    def backup_storage_manager
+      Danbooru.config.backup_storage_manager
+    end
+
     def storage_manager
       Danbooru.config.storage_manager
     end
@@ -263,23 +270,6 @@ class Post < ApplicationRecord
     end
   end
 
-  module BackupMethods
-    extend ActiveSupport::Concern
-
-    def queue_backup
-      Post.delay(queue: "default", priority: -1).backup_file(file_path, id: id, type: :original)
-      Post.delay(queue: "default", priority: -1).backup_file(large_file_path, id: id, type: :large) if has_large?
-      Post.delay(queue: "default", priority: -1).backup_file(preview_file_path, id: id, type: :preview) if has_preview?
-    end
-
-    module ClassMethods
-      def backup_file(file_path, options = {})
-        backup_service = Danbooru.config.backup_service
-        backup_service.backup(file_path, options)
-      end
-    end
-  end
-
   module ImageMethods
     def twitter_card_supported?
       image_width.to_i >= 280 && image_height.to_i >= 150
@@ -1800,7 +1790,6 @@ class Post < ApplicationRecord
   end
   
   include FileMethods
-  include BackupMethods
   include ImageMethods
   include ApprovalMethods
   include PresenterMethods

app/models/post_replacement.rb

@@ -71,8 +71,6 @@ class PostReplacement < ApplicationRecord
 
       if md5_changed
         post.comments.create!({creator: User.system, body: comment_replacement_message, do_not_bump_post: true}, without_protection: true)
-      else
-        post.queue_backup
       end
 
       save!