input       chan *queueItem // input for workers
	queue       chan *queueItem // output from workers in order
	err         error           // global error state, only touched by Reader.Read
	bufferPool  sync.Pool       // pool of []byte objects for input
	kvDstPool   sync.Pool       // pool of []jstream.KV used for output
	close       chan struct{}   // used for shutting down the splitter before end of stream