gitlab-org--gitlab-foss/app/services/projects/batch_forks_count_service.rb

# Service class for getting and caching the number of forks of several projects
# Warning: do not user this service with a really large set of projects
# because the service use maps to retrieve the project ids
module Projects
  class BatchForksCountService < Projects::BatchCountService
    def global_count
      @global_count ||= begin
        count_service.query(project_ids)
                     .group(:forked_from_project_id)
                     .count
      end
    end

    def count_service
      ::Projects::ForksCountService
    end
  end
end