Show counters for total data transferred (fixes #265)

protocol/counting.go

@@ -10,9 +10,15 @@ type countingReader struct {
 	tot uint64
 }
 
+var (
+	totalIncoming uint64
+	totalOutgoing uint64
+)
+
 func (c *countingReader) Read(bs []byte) (int, error) {
 	n, err := c.Reader.Read(bs)
 	atomic.AddUint64(&c.tot, uint64(n))
+	atomic.AddUint64(&totalIncoming, uint64(n))
 	return n, err
 }
 
@@ -28,9 +34,14 @@ type countingWriter struct {
 func (c *countingWriter) Write(bs []byte) (int, error) {
 	n, err := c.Writer.Write(bs)
 	atomic.AddUint64(&c.tot, uint64(n))
+	atomic.AddUint64(&totalOutgoing, uint64(n))
 	return n, err
 }
 
 func (c *countingWriter) Tot() uint64 {
 	return atomic.LoadUint64(&c.tot)
 }
+
+func TotalInOut() (uint64, uint64) {
+	return atomic.LoadUint64(&totalIncoming), atomic.LoadUint64(&totalOutgoing)
+}