Merge pull request #602 from allencloud/refactor-code-in-xen

refactor codes in xen to be more readable

Author: gao-feng

hypervisor/xen/xen.go

@@ -63,24 +63,25 @@ func InitDriver() *XenDriver {
 	if res != 0 {
 		glog.Info("failed to initialize xen context")
 		return nil
-	} else if ctx.Version < REQUIRED_VERSION {
+	}
+	if ctx.Version < REQUIRED_VERSION {
 		glog.Infof("Xen version is not new enough (%d), need 4.5 or higher", ctx.Version)
 		return nil
-	} else {
-		glog.V(1).Info("Xen capabilities: ", ctx.Capabilities)
-		hvm := false
-		caps := strings.Split(ctx.Capabilities, " ")
-		for _, cap := range caps {
-			if strings.HasPrefix(cap, "hvm-") {
-				hvm = true
-				break
-			}
-		}
-		if !hvm {
-			glog.Infof("Xen installation does not support HVM, current capabilities: %s", ctx.Capabilities)
-			return nil
+	}
+
+	glog.V(1).Info("Xen capabilities: ", ctx.Capabilities)
+	hvm := false
+	caps := strings.Split(ctx.Capabilities, " ")
+	for _, cap := range caps {
+		if strings.HasPrefix(cap, "hvm-") {
+			hvm = true
+			break
 		}
 	}
+	if !hvm {
+		glog.Infof("Xen installation does not support HVM, current capabilities: %s", ctx.Capabilities)
+		return nil
+	}
 
 	sigchan := make(chan os.Signal, 1)
 	go func() {
@@ -130,19 +131,18 @@ func (xd *XenDriver) LoadContext(persisted map[string]interface{}) (hypervisor.D
 	d, ok := persisted["domid"]
 	if !ok {
 		return nil, errors.New("cannot read the dom id info from persist info")
-	} else {
-		switch d.(type) {
-		case float64:
-			domid = (int)(d.(float64))
-			if domid <= 0 {
-				return nil, fmt.Errorf("loaded wrong domid %d", domid)
-			}
-			if HyperxlDomainCheck(xd.Ctx, (uint32)(domid)) != 0 {
-				return nil, fmt.Errorf("cannot load domain %d, not exist", domid)
-			}
-		default:
-			return nil, errors.New("wrong domid type in persist info")
+	}
+	switch d.(type) {
+	case float64:
+		domid = (int)(d.(float64))
+		if domid <= 0 {
+			return nil, fmt.Errorf("loaded wrong domid %d", domid)
+		}
+		if HyperxlDomainCheck(xd.Ctx, (uint32)(domid)) != 0 {
+			return nil, fmt.Errorf("cannot load domain %d, not exist", domid)
 		}
+	default:
+		return nil, errors.New("wrong domid type in persist info")
 	}
 
 	return &XenContext{driver: xd, domId: domid}, nil
@@ -244,38 +244,37 @@ func (xc *XenContext) AddNic(ctx *hypervisor.VmContext, host *hypervisor.HostNic
 
 		glog.V(1).Infof("allocate nic %s for dom %d", host.Mac, xc.domId)
 		hw, err := net.ParseMAC(host.Mac)
-		if err == nil {
-			dev := host.Device
-			glog.V(1).Infof("add network for %d - ip: %s, br: %s, gw: %s, dev: %s, hw: %s", xc.domId, guest.Ipaddr,
-				host.Bridge, host.Bridge, dev, hw.String())
-
-			res := HyperxlNicAdd(xc.driver.Ctx, (uint32)(xc.domId), guest.Ipaddr[0], host.Bridge, host.Bridge, dev, []byte(hw))
-			if res == 0 {
-
-				glog.V(1).Infof("nic %s insert succeeded", guest.Device)
-
-				err = network.UpAndAddToBridge(dev, "", "")
-				if err != nil {
-					glog.Error("fail to add vif to bridge: ", err.Error())
-					ctx.Hub <- &hypervisor.DeviceFailed{
-						Session: callback,
-					}
-					HyperxlNicRemove(xc.driver.Ctx, (uint32)(xc.domId), host.Mac)
-					return
-				}
-
-				result <- callback
-				return
+		if err != nil {
+			glog.Errorf("failed to parse MAC %s: %v", host.Mac, err)
+			result <- &hypervisor.DeviceFailed{
+				Session: callback,
 			}
+			return
+		}
+		dev := host.Device
+		glog.V(1).Infof("add network for %d - ip: %s, br: %s, gw: %s, dev: %s, hw: %s", xc.domId, guest.Ipaddr,
+			host.Bridge, host.Bridge, dev, hw.String())
+
+		res := HyperxlNicAdd(xc.driver.Ctx, (uint32)(xc.domId), guest.Ipaddr[0], host.Bridge, host.Bridge, dev, []byte(hw))
+		if res != 0 {
 			glog.V(1).Infof("nic %s insert succeeded [faked] ", guest.Device)
 			result <- callback
 			return
 		}
 
-		glog.Errorf("nic %s insert failed", guest.Device)
-		result <- &hypervisor.DeviceFailed{
+		glog.V(1).Infof("nic %s insert succeeded", guest.Device)
+
+		if err := network.UpAndAddToBridge(dev, "", ""); err == nil {
+			result <- callback
+			return
+		}
+		glog.Error("fail to add vif to bridge: ", err.Error())
+		ctx.Hub <- &hypervisor.DeviceFailed{
 			Session: callback,
 		}
+
+		HyperxlNicRemove(xc.driver.Ctx, (uint32)(xc.domId), host.Mac)
+		return
 	}()
 }