1 files changed, 45 insertions, 0 deletions
diff --git a/dna/writer.go b/dna/writer.go
new file mode 100644
index 0000000..6b232cd
--- /dev/null
+++ b/dna/writer.go
@@ -0,0 +1,45 @@
+/* Copyright (C) 2021 Nicolas Peugnet <n.peugnet@free.fr>
+
+   This file is part of dna-backup.
+
+   dna-backup 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.
+
+   dna-backup 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 dna-backup.  If not, see <https://www.gnu.org/licenses/>. */
+
+package dna
+
+import (
+	"io"
+
+	"github.com/n-peugnet/dna-backup/utils"
+)
+
+type writer struct {
+	*utils.WriteCounter
+	trackSize int
+}
+
+func NewWriter(w io.Writer, trackSize int) io.WriteCloser {
+	return &writer{
+		WriteCounter: utils.NewWriteCounter(w),
+		trackSize:    trackSize,
+	}
+}
+
+func (d *writer) Close() (err error) {
+	// add padding for the last track
+	padding := make([]byte, d.trackSize-d.Count()%d.trackSize)
+	if _, err = d.Write(padding); err != nil {
+		return err
+	}
+	return nil
+}