Zero bytesSyncLogger stats after reading them

This also makes the call to GetStat() more thread safe.

proxy/lib/util.go

@@ -27,16 +27,22 @@ func (b bytesNullLogger) GetStat() (in int64, out int64) { return -1, -1 }
 // occuring at reasonable intervals.
 type bytesSyncLogger struct {
 	outboundChan, inboundChan chan int64
-	outbound, inbound         int64
+	statsChan                 chan bytesLoggerStats
+	stats                     bytesLoggerStats
 	outEvents, inEvents       int
 	start                     time.Time
 }
 
+type bytesLoggerStats struct {
+	outbound, inbound int64
+}
+
 // newBytesSyncLogger returns a new bytesSyncLogger and starts it loggin.
 func newBytesSyncLogger() *bytesSyncLogger {
 	b := &bytesSyncLogger{
 		outboundChan: make(chan int64, 5),
 		inboundChan:  make(chan int64, 5),
+		statsChan:    make(chan bytesLoggerStats),
 	}
 	go b.log()
 	b.start = time.Now()
@@ -47,11 +53,16 @@ func (b *bytesSyncLogger) log() {
 	for {
 		select {
 		case amount := <-b.outboundChan:
-			b.outbound += amount
+			b.stats.outbound += amount
 			b.outEvents++
 		case amount := <-b.inboundChan:
-			b.inbound += amount
+			b.stats.inbound += amount
 			b.inEvents++
+		case b.statsChan <- b.stats:
+			b.stats.inbound = 0
+			b.stats.outbound = 0
+			b.inEvents = 0
+			b.outEvents = 0
 		}
 	}
 }
@@ -66,6 +77,10 @@ func (b *bytesSyncLogger) AddInbound(amount int64) {
 	b.inboundChan <- amount
 }
 
-func (b *bytesSyncLogger) GetStat() (in int64, out int64) { return b.inbound, b.outbound }
+// GetStat returns the current inbound and outbound stats from the logger and then zeros the counts
+func (b *bytesSyncLogger) GetStat() (in int64, out int64) {
+	stats := <-b.statsChan
+	return stats.inbound, stats.outbound
+}
 
 func formatTraffic(amount int64) (value int64, unit string) { return amount / 1000, "KB" }