@@ -0,0 +1,34 @@
+package multibuf
+
+import (
+	"io"
+)
+
+type WriteCloser struct {
+	writers []io.WriteCloser
+	io.Writer
+}
+
+func NewWriteCloser(writers ...io.WriteCloser) *WriteCloser {
+	ws := make([]io.Writer, len(writers))
+	for i, w := range writers {
+		ws[i] = io.Writer(w)
+	}
+
+	return &WriteCloser{
+		writers: writers,
+		Writer:  io.MultiWriter(ws...),
+	}
+}
+
+func (mw *WriteCloser) Close() error {
+	var lastErr error
+	for _, w := range mw.writers {
+		err := w.Close()
+		if err != nil {
+			lastErr = err
+		}
+	}
+
+	return lastErr
+}

@@ -8,6 +8,7 @@ "path/filepath"
 	"time"
 
 	"go.alanpearce.eu/website/internal/buffer"
+	"go.alanpearce.eu/website/internal/multibuf"
 	"go.alanpearce.eu/website/internal/storage"
 	"go.alanpearce.eu/x/log"
 
@@ -79,27 +80,6 @@
 	return nil
 }
 
-type MultiWriteCloser struct {
-	writers     []io.WriteCloser
-	multiWriter io.Writer
-}
-
-func (mw *MultiWriteCloser) Write(p []byte) (n int, err error) {
-	return mw.multiWriter.Write(p)
-}
-
-func (mw *MultiWriteCloser) Close() error {
-	var lastErr error
-	for _, w := range mw.writers {
-		err := w.Close()
-		if err != nil {
-			lastErr = err
-		}
-	}
-
-	return lastErr
-}
-
 func openFileWrite(filename string) (*os.File, error) {
 	return os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
 }
@@ -124,7 +104,7 @@
 	return brotli.NewWriterLevel(f, brotliLevel), nil
 }
 
-func multiOpenFile(filename string) (*MultiWriteCloser, error) {
+func multiOpenFile(filename string) (*multibuf.WriteCloser, error) {
 	r, err := openFileWrite(filename)
 	if err != nil {
 		return nil, err
@@ -138,10 +118,7 @@ if err != nil {
 		return nil, err
 	}
 
-	return &MultiWriteCloser{
-		writers:     []io.WriteCloser{r, gz, br},
-		multiWriter: io.MultiWriter(r, gz, br),
-	}, nil
+	return multibuf.NewWriteCloser(r, gz, br), nil
 }
 
 func (f *Files) OpenFileAndVariants(filename string) (io.WriteCloser, error) {