Refactor: Extract more checksum methods

Out of Gitlab::Geo::Replicator, and into the Geo::VerifiableReplicator
concern.

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

@@ -4,7 +4,7 @@ module Geo
   module RepositoryReplicatorStrategy
     extend ActiveSupport::Concern
 
-    include Delay
+    include ::Geo::VerifiableReplicator
     include Gitlab::Geo::LogHelpers
 
     included do

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

@@ -6,6 +6,20 @@ module Geo
 
     include Delay
 
+    class_methods do
+      def checksummed
+        model.available_replicables.checksummed
+      end
+
+      def checksummed_count
+        model.available_replicables.checksummed.count
+      end
+
+      def checksum_failed_count
+        model.available_replicables.checksum_failed.count
+      end
+    end
+
     def after_verifiable_update
       schedule_checksum_calculation if needs_checksum?
     end
@@ -26,6 +40,23 @@ module Geo
       model_record.verification_checksum == checksum
     end
 
+    def needs_checksum?
+      return true unless model_record.respond_to?(:needs_checksum?)
+
+      model_record.needs_checksum?
+    end
+
+    # Checksum value from the main database
+    #
+    # @abstract
+    def primary_checksum
+      model_record.verification_checksum
+    end
+
+    def secondary_checksum
+      registry.verification_checksum
+    end
+
     private
 
     # Update checksum on Geo primary database
@@ -48,5 +79,9 @@ module Geo
       retry_count = model_record.verification_retry_count.to_i + 1
       [next_retry_time(retry_count), retry_count]
     end
+
+    def schedule_checksum_calculation
+      raise NotImplementedError
+    end
   end
 end

ee/lib/gitlab/geo/replicator.rb

@@ -134,18 +134,6 @@ module Gitlab
         replicator_class.new(model_record_id: replicable_id)
       end
 
-      def self.checksummed
-        model.available_replicables.checksummed
-      end
-
-      def self.checksummed_count
-        model.available_replicables.checksummed.count
-      end
-
-      def self.checksum_failed_count
-        model.available_replicables.checksum_failed.count
-      end
-
       def self.primary_total_count
         model.available_replicables.count
       end
@@ -265,17 +253,6 @@ module Gitlab
         registry_class.for_model_record_id(model_record_id)
       end
 
-      # Checksum value from the main database
-      #
-      # @abstract
-      def primary_checksum
-        model_record.verification_checksum
-      end
-
-      def secondary_checksum
-        registry.verification_checksum
-      end
-
       # Return exactly the data needed by `for_replicable_params` to
       # reinstantiate this Replicator elsewhere.
       #
@@ -298,10 +275,6 @@ module Gitlab
         publish(:updated, **updated_params)
       end
 
-      def schedule_checksum_calculation
-        raise NotImplementedError
-      end
-
       def created_params
         event_params
       end
@@ -318,12 +291,6 @@ module Gitlab
         { model_record_id: model_record.id }
       end
 
-      def needs_checksum?
-        return true unless model_record.respond_to?(:needs_checksum?)
-
-        model_record.needs_checksum?
-      end
-
       protected
 
       # Store an event on the database