Break out some Geo registry basics into a concern

There was quite a bit of functionality `Geo::PackageFileRegistry` which
can be reused by all the Geo registries that will use the self-service
framework.

To make this easier I've moved everything into a concern.

Closes https://gitlab.com/gitlab-org/gitlab/-/issues/221029

doc/development/geo/framework.md

@@ -259,7 +259,7 @@ For example, to add support for files referenced by a `Widget` model with a
    # frozen_string_literal: true
 
    class Geo::WidgetRegistry < Geo::BaseRegistry
-     include Geo::StateMachineRegistry
+     include Geo::ReplicableRegistry
 
      MODEL_CLASS = ::Widget
      MODEL_FOREIGN_KEY = :widget_id

ee/app/models/concerns/geo/replicable_registry.rb

+# frozen_string_literal: true
+
+module Geo::ReplicableRegistry
+  extend ActiveSupport::Concern
+
+  STATE_VALUES = {
+    pending: 0,
+    started: 1,
+    synced: 2,
+    failed: 3
+  }.freeze
+
+  class_methods do
+    def state_value(state_string)
+      STATE_VALUES[state_string]
+    end
+
+    def for_model_record_id(id)
+      find_or_initialize_by(self::MODEL_FOREIGN_KEY => id)
+    end
+
+    def declarative_policy_class
+      'Geo::RegistryPolicy'
+    end
+  end
+
+  included do
+    include ::Delay
+
+    scope :never, -> { where(last_synced_at: nil) }
+    scope :failed, -> { with_state(:failed) }
+    scope :synced, -> { with_state(:synced) }
+    scope :pending, -> { with_state(:pending) }
+    scope :retry_due, -> { where(arel_table[:retry_at].eq(nil).or(arel_table[:retry_at].lt(Time.current))) }
+    scope :ordered, -> { order(:id) }
+
+    state_machine :state, initial: :pending do
+      state :pending, value: STATE_VALUES[:pending]
+      state :started, value: STATE_VALUES[:started]
+      state :synced, value: STATE_VALUES[:synced]
+      state :failed, value: STATE_VALUES[:failed]
+
+      before_transition any => :started do |registry, _|
+        registry.last_synced_at = Time.current
+      end
+
+      before_transition any => :pending do |registry, _|
+        registry.retry_at = 0
+        registry.retry_count = 0
+      end
+
+      before_transition any => :failed do |registry, _|
+        registry.retry_count += 1
+        registry.retry_at = registry.next_retry_time(registry.retry_count)
+      end
+
+      before_transition any => :synced do |registry, _|
+        registry.retry_count = 0
+        registry.last_sync_failure = nil
+        registry.retry_at = nil
+      end
+
+      event :start do
+        transition [:pending, :synced, :failed] => :started
+      end
+
+      event :synced do
+        transition [:started] => :synced
+      end
+
+      event :failed do
+        transition [:started] => :failed
+      end
+
+      event :resync do
+        transition [:synced, :failed] => :pending
+      end
+    end
+
+    # Override state machine failed! event method to record a failure message at
+    # the same time.
+    #
+    # @param [String] message error information
+    # @param [StandardError] error exception
+    def failed!(message, error = nil)
+      self.last_sync_failure = message
+      self.last_sync_failure += ": #{error.message}" if error.respond_to?(:message)
+
+      super()
+    end
+  end
+end

ee/app/models/geo/package_file_registry.rb

 # frozen_string_literal: true
 
 class Geo::PackageFileRegistry < Geo::BaseRegistry
-  include ::Delay
+  include ::Geo::ReplicableRegistry
   include ShaAttribute
 
   MODEL_CLASS = ::Packages::PackageFile
   MODEL_FOREIGN_KEY = :package_file_id
 
-  def self.declarative_policy_class
-    'Geo::RegistryPolicy'
-  end
-
-  STATE_VALUES = {
-    pending: 0,
-    started: 1,
-    synced: 2,
-    failed: 3
-  }.freeze
-
   belongs_to :package_file, class_name: 'Packages::PackageFile'
 
-  scope :never, -> { where(last_synced_at: nil) }
-  scope :failed, -> { with_state(:failed) }
-  scope :synced, -> { with_state(:synced) }
-  scope :pending, -> { with_state(:pending) }
-  scope :retry_due, -> { where(arel_table[:retry_at].eq(nil).or(arel_table[:retry_at].lt(Time.current))) }
-  scope :ordered, -> { order(:id) }
-
-  state_machine :state, initial: :pending do
-    state :pending, value: STATE_VALUES[:pending]
-    state :started, value: STATE_VALUES[:started]
-    state :synced, value: STATE_VALUES[:synced]
-    state :failed, value: STATE_VALUES[:failed]
-
-    before_transition any => :started do |registry, _|
-      registry.last_synced_at = Time.current
-    end
-
-    before_transition any => :pending do |registry, _|
-      registry.retry_at = 0
-      registry.retry_count = 0
-    end
-
-    before_transition any => :failed do |registry, _|
-      registry.retry_count += 1
-      registry.retry_at = registry.next_retry_time(registry.retry_count)
-    end
-
-    before_transition any => :synced do |registry, _|
-      registry.retry_count = 0
-      registry.last_sync_failure = nil
-      registry.retry_at = nil
-    end
-
-    event :start do
-      transition [:pending, :synced, :failed] => :started
-    end
-
-    event :synced do
-      transition [:started] => :synced
-    end
-
-    event :failed do
-      transition [:started] => :failed
-    end
-
-    event :resync do
-      transition [:synced, :failed] => :pending
-    end
-  end
-
   sha_attribute :verification_checksum
   sha_attribute :verification_checksum_mismatched
 
-  # @return [Geo::PackageFileRegistry] an instance of this class
-  def self.for_model_record_id(id)
-    find_or_initialize_by(package_file_id: id)
-  end
-
-  def self.state_value(state_string)
-    STATE_VALUES[state_string]
-  end
-
   def self.has_create_events?
     true
   end
 
-  # Override state machine failed! event method to record a failure message at
-  # the same time.
-  #
-  # @param [String] message error information
-  # @param [StandardError] error exception
-  def failed!(message, error = nil)
-    self.last_sync_failure = message
-    self.last_sync_failure += ": #{error.message}" if error.respond_to?(:message)
-
-    super()
-  end
-
   def self.delete_for_model_ids(package_file_ids)
     # TODO: https://gitlab.com/gitlab-org/gitlab/-/issues/222635
     []