# File lib/sqlite3/driver/dl/driver.rb, line 280
      def commit_hook( db, data=nil, &block )
        @commit_hook_handler = block

        unless @commit_hook_handler_callback
          @commit_hook_handler_callback = ::DL.callback( "IP" ) do |cookie|
            @commit_hook_handler.call( cookie )
          end
        end

        API.sqlite3_commit_hook( db, block&&@commit_hook_handler_callback,
          data )
      end