Mirror: only hit all sites for upload and delete

The mirror service exists for the purpose of migration, where all blobs exist in the primary subservice and a subset of blobs exist in the secondary subservice. Since the primary subservice is the source of truth until a migration is completed, operations like existence checks need not be performed against the secondary subservices.

1 files changed, 4 insertions, 21 deletions

diff --git a/lib/active_storage/service/mirror_service.rb b/lib/active_storage/service/mirror_service.rb
index 2a3518e59e..0d37ad96a3 100644
--- a/lib/active_storage/service/mirror_service.rb
+++ b/lib/active_storage/service/mirror_service.rb
@@ -1,6 +1,10 @@
+require "active_support/core_ext/module/delegation"
+
 class ActiveStorage::Service::MirrorService < ActiveStorage::Service
   attr_reader :services
 
+  delegate :download, :exist?, :url, :byte_size, :checksum, to: :primary_service
+
   def initialize(services:)
     @services = services
   end
@@ -12,31 +16,10 @@ class ActiveStorage::Service::MirrorService < ActiveStorage::Service
     end
   end
 
-  def download(key)
-    services.detect { |service| service.exist?(key) }.download(key)
-  end
-
   def delete(key)
     perform_across_services :delete, key
   end
 
-  def exist?(key)
-    perform_across_services(:exist?, key).any?
-  end
-
-
-  def url(key, **options)
-    primary_service.url(key, **options)
-  end
-
-  def byte_size(key)
-    primary_service.byte_size(key)
-  end
-
-  def checksum(key)
-    primary_service.checksum(key)
-  end
-
   private
     def primary_service
       services.first