batching.go

package main

import "bufio"

func writing(buf *bufio.Writer, input <-chan []byte) (err error) {
	var data []byte
	var more = true
	for more && err == nil {
		select {
		case data, more = <-input:
			_, err = buf.Write(data)
			continue
		default:
		}
		if err = buf.Flush(); err == nil {
			data, more = <-input
			_, err = buf.Write(data)
		}
	}
	return err
}