sock/multiwriter.go

package sock

import "io"

type multiWriter struct {
	writers []io.Writer
}

var _ io.Writer = &multiWriter{}

func (t *multiWriter) Write(p []byte) (n int, err error) {
	for _, w := range t.writers {
		w.Write(p)
	}
	return len(p), nil
}

func newMultiWriter(writers ...io.Writer) io.Writer {
	allWriters := make([]io.Writer, 0, len(writers))
	for _, w := range writers {
		if mw, ok := w.(*multiWriter); ok {
			allWriters = append(allWriters, mw.writers...)
		} else {
			allWriters = append(allWriters, w)
		}
	}
	return &multiWriter{allWriters}
}