1 files changed, 62 insertions, 0 deletions
diff --git a/app/services/ci/delete_objects_service.rb b/app/services/ci/delete_objects_service.rb
new file mode 100644
index 00000000000..bac99abadc9
--- /dev/null
+++ b/app/services/ci/delete_objects_service.rb
@@ -0,0 +1,62 @@
+# frozen_string_literal: true
+
+module Ci
+  class DeleteObjectsService
+    TransactionInProgressError = Class.new(StandardError)
+    TRANSACTION_MESSAGE = "can't perform network calls inside a database transaction"
+    BATCH_SIZE = 100
+    RETRY_IN = 10.minutes
+
+    def execute
+      objects = load_next_batch
+      destroy_everything(objects)
+    end
+
+    def remaining_batches_count(max_batch_count:)
+      Ci::DeletedObject
+        .ready_for_destruction(max_batch_count * BATCH_SIZE)
+        .size
+        .fdiv(BATCH_SIZE)
+        .ceil
+    end
+
+    private
+
+    # rubocop: disable CodeReuse/ActiveRecord
+    def load_next_batch
+      # `find_by_sql` performs a write in this case and we need to wrap it in
+      # a transaction to stick to the primary database.
+      Ci::DeletedObject.transaction do
+        Ci::DeletedObject.find_by_sql([
+          next_batch_sql, new_pick_up_at: RETRY_IN.from_now
+        ])
+      end
+    end
+    # rubocop: enable CodeReuse/ActiveRecord
+
+    def next_batch_sql
+      <<~SQL.squish
+      UPDATE "ci_deleted_objects"
+        SET "pick_up_at" = :new_pick_up_at
+        WHERE "ci_deleted_objects"."id" IN (#{locked_object_ids_sql})
+        RETURNING *
+      SQL
+    end
+
+    def locked_object_ids_sql
+      Ci::DeletedObject.lock_for_destruction(BATCH_SIZE).to_sql
+    end
+
+    def destroy_everything(objects)
+      raise TransactionInProgressError, TRANSACTION_MESSAGE if transaction_open?
+      return unless objects.any?
+
+      deleted = objects.select(&:delete_file_from_storage)
+      Ci::DeletedObject.id_in(deleted.map(&:id)).delete_all
+    end
+
+    def transaction_open?
+      Ci::DeletedObject.connection.transaction_open?
+    end
+  end
+end