require "active_support/core_ext/module/delegation"
module ActiveStorage
# Wraps a set of mirror services and provides a single `ActiveStorage::Service` object that will all
# have the files uploaded to them. A `primary` service is designated to answer calls to `download`, `exists?`,
# and `url`.
class Service::MirrorService < 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
# Upload the `io` to the `key` specified to all services. If a `checksum` is provided, all services will
# ensure a match when the upload has completed or raise an `ActiveStorage::IntegrityError`.
def upload(key, io, checksum: nil)
each_service.collect do |service|
service.upload key, io.tap(&:rewind), checksum: checksum
end
end
# Delete the file at the `key` on all services.
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
end
