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Class: ActiveStorage::Service::MirrorService

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::ActiveStorage::Service, ::ActiveSupport::Autoload
Instance Chain:
self, ::ActiveStorage::Service
Inherits: ActiveStorage::Service
Defined in: activestorage/lib/active_storage/service/mirror_service.rb

Overview

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:

Class Method Summary

::ActiveStorage::Service - Inherited

.configure

Configure an Active Storage service by name from a set of configurations, typically loaded from a YAML file.
.build

Override in subclasses that stitch together multiple services and hence need to build additional services using the configurator.

::ActiveSupport::Autoload - Extended

autoload, autoload_at, autoload_under, eager_autoload, eager_load!

Instance Attribute Summary

::ActiveStorage::Service - Inherited

#name, #public?

Instance Method Summary

::ActiveStorage::Service - Inherited

#compose

Concatenate multiple files into a single “composed” file.
#delete

Delete the file at the key.
#delete_prefixed

Delete files at keys starting with the prefix.
#download

Return the content of the file at the key.
#download_chunk

Return the partial content in the byte range of the file at the key.
#exist?

Return true if a file exists at the key.
#headers_for_direct_upload

Returns a ::Hash of headers for #url_for_direct_upload requests.
#open,
#update_metadata

Update metadata for the file identified by key in the service.
#upload

Upload the io to the key specified.
#url

Returns the URL for the file at the key.
#url_for_direct_upload

Returns a signed, temporary URL that a direct upload file can be PUT to on the key.
#content_disposition_with, #custom_metadata_headers, #instrument, #private_url, #public_url, #service_name

Constructor Details

.new(primary:, mirrors:) ⇒ MirrorService

[ GitHub ] 

  


# 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


  







Class Method Details



  

    .build(primary:, mirrors:, name:, configurator:, **options)  
  

  

    This method is for internal use only.
  



  

    

Stitch together from named services.


  



  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 22



def self.build(primary:, mirrors:, name:, configurator:, **options) # :nodoc:
  new(
    primary: configurator.build(primary),
    mirrors: mirrors.collect { |mirror_name| configurator.build mirror_name }
  ).tap do |service_instance|
    service_instance.name = name
  end
end


  







Instance Attribute Details



  

    #compose   (readonly)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 18



delegate :download, :download_chunk, :exist?, :url,
  :url_for_direct_upload, :headers_for_direct_upload, :path_for, :compose, to: :primary


  








  

    #download   (readonly)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 18



delegate :download, :download_chunk, :exist?, :url,
  :url_for_direct_upload, :headers_for_direct_upload, :path_for, :compose, to: :primary


  








  

    #download_chunk   (readonly)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 18



delegate :download, :download_chunk, :exist?, :url,
  :url_for_direct_upload, :headers_for_direct_upload, :path_for, :compose, to: :primary


  








  

    #headers_for_direct_upload   (readonly)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 18



delegate :download, :download_chunk, :exist?, :url,
  :url_for_direct_upload, :headers_for_direct_upload, :path_for, :compose, to: :primary


  








  

    #mirrors   (readonly)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 16



attr_reader :primary, :mirrors


  








  

    #path_for   (readonly)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 18



delegate :download, :download_chunk, :exist?, :url,
  :url_for_direct_upload, :headers_for_direct_upload, :path_for, :compose, to: :primary


  








  

    #primary   (readonly)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 16



attr_reader :primary, :mirrors


  








  

    #url   (readonly)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 18



delegate :download, :download_chunk, :exist?, :url,
  :url_for_direct_upload, :headers_for_direct_upload, :path_for, :compose, to: :primary


  








  

    #url_for_direct_upload   (readonly)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 18



delegate :download, :download_chunk, :exist?, :url,
  :url_for_direct_upload, :headers_for_direct_upload, :path_for, :compose, to: :primary


  







Instance Method Details



  

    #delete(key)  
  



  

    

Delete the file at the key on all services.


  



  [ GitHub ]


  

  


# 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.


  



  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 57



def delete_prefixed(prefix)
  perform_across_services :delete_prefixed, prefix
end


  








  

    #each_service(&block)   (private)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 80



def each_service(&block)
  [ primary, *mirrors ].each(&block)
end


  








  

    #exist?  ⇒ Boolean 
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 18



delegate :download, :download_chunk, :exist?, :url,
  :url_for_direct_upload, :headers_for_direct_upload, :path_for, :compose, to: :primary


  








  

    #mirror(key, checksum:)  
  



  

    

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


  



  [ GitHub ]


  

  


# 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


  








  

    #mirror_later(key, checksum:)  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 61



def mirror_later(key, checksum:) # :nodoc:
  ActiveStorage::MirrorJob.perform_later key, checksum: checksum
end


  








  

    #perform_across_services(method, *args)   (private)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/service/mirror_service.rb', line 84



def perform_across_services(method, *args)
  tasks = each_service.collect do |service|
    Concurrent::Promise.execute(executor: @executor) do
      service.public_send method, *args
    end
  end
  tasks.each(&:value!)
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.


  



  [ GitHub ]


  

  


# 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