class ActiveStorage::Service::MirrorService

Active Storage Mirror Service ↑

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?

  • url

  • url_for_direct_upload

  • headers_for_direct_upload

Attributes

Public Class Methods

new (primary:, mirrors:) 
# File activestorage/lib/active_storage/service/mirror_service.rb, line 31
def initialize(primary:, mirrors:)
  @primary, @mirrors = primary, mirrors
  @executor = Concurrent::ThreadPoolExecutor.new(
    min_threads: 1,
    max_threads: mirrors.size,
    max_queue: 0,
    fallback_policy: :caller_runs,
    idle_time: 60
  )
end

Public Instance Methods

delete (key)

Delete the file at the key on all services.

# File activestorage/lib/active_storage/service/mirror_service.rb, line 52
def delete(key)
  perform_across_services :delete, key
end
delete_prefixed (prefix)

Delete files at keys starting with the prefix on all services.

# File activestorage/lib/active_storage/service/mirror_service.rb, line 57
def delete_prefixed(prefix)
  perform_across_services :delete_prefixed, prefix
end
mirror (key, checksum:)

Copy the file at the key from the primary service to each of the mirrors where it doesn’t already exist.

# File activestorage/lib/active_storage/service/mirror_service.rb, line 66
def mirror(key, checksum:)
  instrument :mirror, key: key, checksum: checksum do
    if (mirrors_in_need_of_mirroring = mirrors.select { |service| !service.exist?(key) }).any?
      primary.open(key, checksum: checksum) do |io|
        mirrors_in_need_of_mirroring.each do |service|
          io.rewind
          service.upload key, io, checksum: checksum
        end
      end
    end
  end
end
upload (key, io, checksum: nil, **options)

Upload the io to the key specified to all services. The upload to the primary service is done synchronously whereas the upload to the mirrors is done asynchronously. If a checksum is provided, all services will ensure a match when the upload has completed or raise an ActiveStorage::IntegrityError.

# File activestorage/lib/active_storage/service/mirror_service.rb, line 45
def upload(key, io, checksum: nil, **options)
  io.rewind
  primary.upload key, io, checksum: checksum, **options
  mirror_later key, checksum: checksum
end