Move keepalive out of mgm pkg

keepalive/monitor.go

@@ -0,0 +1,32 @@
+package keepalive
+
+import (
+	"sync"
+	"time"
+
+	"google.golang.org/grpc"
+)
+
+type ioMonitor struct {
+	mu sync.Mutex
+	grpc.ServerStream
+	lastSeen time.Time
+}
+
+func (l *ioMonitor) sendMsg(m interface{}) error {
+	l.updateLastSeen()
+	return l.ServerStream.SendMsg(m)
+}
+
+func (l *ioMonitor) updateLastSeen() {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	l.lastSeen = time.Now()
+}
+
+func (l *ioMonitor) getLastSeen() time.Time {
+	l.mu.Lock()
+	t := l.lastSeen
+	l.mu.Unlock()
+	return t
+}