syncthing/internal/osutil/replacingwriter.go
2014-11-17 12:54:42 +01:00

58 lines
1.3 KiB
Go

// Copyright (C) 2014 The Syncthing Authors.
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along
// with this program. If not, see <http://www.gnu.org/licenses/>.
package osutil
import (
"bytes"
"io"
)
type ReplacingWriter struct {
Writer io.Writer
From byte
To []byte
}
func (w ReplacingWriter) Write(bs []byte) (int, error) {
var n, written int
var err error
newlineIdx := bytes.IndexByte(bs, w.From)
for newlineIdx >= 0 {
n, err = w.Writer.Write(bs[:newlineIdx])
written += n
if err != nil {
break
}
if len(w.To) > 0 {
n, err := w.Writer.Write(w.To)
if n == len(w.To) {
written++
}
if err != nil {
break
}
}
bs = bs[newlineIdx+1:]
newlineIdx = bytes.IndexByte(bs, w.From)
}
n, err = w.Writer.Write(bs)
written += n
return written, err
}