# File lib/gitlab_git/repository.rb, line 562
      def commit_count(ref)
        walker = Rugged::Walker.new(rugged)
        walker.sorting(Rugged::SORT_TOPO | Rugged::SORT_REVERSE)
        oid = rugged.rev_parse_oid(ref)
        walker.push(oid)
        walker.count
      end