Everything under app/ is eager loaded, don't want that for service

Since it references all the specific cloud services that are intended only to be loaded on demand.

1 files changed, 40 insertions, 0 deletions

diff --git a/lib/active_storage/service/mirror_service.rb b/lib/active_storage/service/mirror_service.rb
new file mode 100644
index 0000000000..54465cad05
--- /dev/null
+++ b/lib/active_storage/service/mirror_service.rb
@@ -0,0 +1,40 @@
+require "active_support/core_ext/module/delegation"
+
+class ActiveStorage::Service::MirrorService < ActiveStorage::Service
+  attr_reader :primary, :mirrors
+
+  delegate :download, :exist?, :url, to: :primary
+
+  # Stitch together from named services.
+  def self.build(primary:, mirrors:, configurator:, **options) #:nodoc:
+    new \
+      primary: configurator.build(primary),
+      mirrors: mirrors.collect { |name| configurator.build name }
+  end
+
+  def initialize(primary:, mirrors:)
+    @primary, @mirrors = primary, mirrors
+  end
+
+  def upload(key, io, checksum: nil)
+    each_service.collect do |service|
+      service.upload key, io.tap(&:rewind), checksum: checksum
+    end
+  end
+
+  def delete(key)
+    perform_across_services :delete, key
+  end
+
+  private
+    def each_service(&block)
+      [ primary, *mirrors ].each(&block)
+    end
+
+    def perform_across_services(method, *args)
+      # FIXME: Convert to be threaded
+      each_service.collect do |service|
+        service.public_send method, *args
+      end
+    end
+end