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/logical/backup_service.rb

@@ -1,9 +0,0 @@
-class BackupService
-  def backup(file_path, options = {})
-    raise NotImplementedError.new("#{self.class}.backup not implemented")
-  end
-
-  def delete(file_path, options = {})
-    raise NotImplementedError.new("#{self.class}.delete not implemented")
-  end
-end

app/logical/null_backup_service.rb

@@ -1,9 +0,0 @@
-class NullBackupService
-  def backup(file_path, options = {})
-    # do nothing
-  end
-
-  def delete(file_path, options = {})
-    # do nothing
-  end
-end

app/logical/s3_backup_service.rb

@@ -1,52 +0,0 @@
-class S3BackupService < BackupService
-  attr_reader :client, :bucket
-
-  def initialize(client: nil, bucket: Danbooru.config.aws_s3_bucket_name)
-    @credentials = Aws::Credentials.new(Danbooru.config.aws_access_key_id, Danbooru.config.aws_secret_access_key)
-    @client = client || Aws::S3::Client.new(credentials: @credentials, region: "us-east-1", logger: Logger.new(STDOUT))
-    @bucket = bucket
-  end
-
-  def backup(file_path, type: nil, **options)
-    keys = s3_keys(file_path, type)
-    keys.each do |key|
-      upload_to_s3(key, file_path)
-    end
-  end
-
-  def delete(file_path, type: nil)
-    keys = s3_keys(file_path, type)
-    keys.each do |key|
-      delete_from_s3(key)
-    end
-  end
-
-protected
-  def s3_keys(file_path, type)
-    name = File.basename(file_path)
-
-    case type
-    when :original
-      [name]
-    when :preview
-      ["preview/#{name}"]
-    when :large
-      ["sample/#{name}"]
-    else
-      raise ArgumentError.new("Unknown type: #{type}")
-    end
-  end
-
-  def delete_from_s3(key)
-    client.delete_object(bucket: bucket, key: key)
-  rescue Aws::S3::Errors::NoSuchKey
-    # ignore
-  end
-
-  def upload_to_s3(key, file_path)
-    File.open(file_path, "rb") do |body|
-      base64_md5 = Digest::MD5.base64digest(File.read(file_path))
-      client.put_object(acl: "public-read", bucket: bucket, key: key, body: body, content_md5: base64_md5)
-    end
-  end
-end

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!