CountWriter added.

1 files changed, 21 insertions, 0 deletions

diff --git a/CountWriter.go b/CountWriter.go
new file mode 100644
index 0000000..d942a8e
--- /dev/null
+++ b/CountWriter.go
@@ -0,0 +1,21 @@
+package kagus
+
+import (
+	"io"
+)
+
+// CountWriter wraps around an io.Writer and counts the amount of bytes written.
+type CountWriter struct {
+	W io.Writer
+	N int64 // Total number of bytes written
+}
+
+func NewCountWriter(w io.Writer) *CountWriter {
+	return &CountWriter{W: w}
+}
+
+func (cw *CountWriter) Write(p []byte) (int, error) {
+	n, err := cw.W.Write(p)
+	cw.N += int64(n)
+	return n, err
+}