package file

import (
	"fmt"
	"os"
)

type LimitedWriter struct {
	File  *os.File
	Limit int64
	n     int64
}

func (lw *LimitedWriter) Write(p []byte) (n int, err error) {
	if lw.n+int64(len(p)) > lw.Limit {
		return 0, fmt.Errorf("output limit exceeded")
	}
	n, err = lw.File.Write(p)
	lw.n += int64(n)
	return
}