client: expose callback function

client/servicediscovery/callbacks.go

@@ -20,23 +20,24 @@ import (
 	"github.com/pingcap/kvproto/pkg/pdpb"
 )
 
-type leaderSwitchedCallbackFunc func(string) error
+// LeaderSwitchedCallbackFunc is the callback function for leader switched event
+type LeaderSwitchedCallbackFunc func(string) error
 
 // serviceCallbacks contains all the callback functions for service discovery events
 type serviceCallbacks struct {
 	sync.RWMutex
 	// serviceModeUpdateCb will be called when the service mode gets updated
 	serviceModeUpdateCb func(pdpb.ServiceMode)
 	// leaderSwitchedCbs will be called after the leader switched
-	leaderSwitchedCbs []leaderSwitchedCallbackFunc
+	leaderSwitchedCbs []LeaderSwitchedCallbackFunc
 	// membersChangedCbs will be called after there is any membership change in the
 	// leader and followers
 	membersChangedCbs []func()
 }
 
 func newServiceCallbacks() *serviceCallbacks {
 	return &serviceCallbacks{
-		leaderSwitchedCbs: make([]leaderSwitchedCallbackFunc, 0),
+		leaderSwitchedCbs: make([]LeaderSwitchedCallbackFunc, 0),
 		membersChangedCbs: make([]func(), 0),
 	}
 }
@@ -47,7 +48,7 @@ func (c *serviceCallbacks) setServiceModeUpdateCallback(cb func(pdpb.ServiceMode
 	c.serviceModeUpdateCb = cb
 }
 
-func (c *serviceCallbacks) addLeaderSwitchedCallback(cb leaderSwitchedCallbackFunc) {
+func (c *serviceCallbacks) addLeaderSwitchedCallback(cb LeaderSwitchedCallbackFunc) {
 	c.Lock()
 	defer c.Unlock()
 	c.leaderSwitchedCbs = append(c.leaderSwitchedCbs, cb)
@@ -72,7 +73,7 @@ func (c *serviceCallbacks) onServiceModeUpdate(mode pdpb.ServiceMode) {
 
 func (c *serviceCallbacks) onLeaderSwitched(leader string) error {
 	c.RLock()
-	cbs := make([]leaderSwitchedCallbackFunc, len(c.leaderSwitchedCbs))
+	cbs := make([]LeaderSwitchedCallbackFunc, len(c.leaderSwitchedCbs))
 	copy(cbs, c.leaderSwitchedCbs)
 	c.RUnlock()
 

client/servicediscovery/mock_service_discovery.go

@@ -101,10 +101,10 @@
 func (*mockServiceDiscovery) CheckMemberChanged() error { return nil }
 
 // ExecAndAddLeaderSwitchedCallback implements the ServiceDiscovery interface.
-func (*mockServiceDiscovery) ExecAndAddLeaderSwitchedCallback(leaderSwitchedCallbackFunc) {}
+func (*mockServiceDiscovery) ExecAndAddLeaderSwitchedCallback(LeaderSwitchedCallbackFunc) {}
 
 // AddLeaderSwitchedCallback implements the ServiceDiscovery interface.
-func (*mockServiceDiscovery) AddLeaderSwitchedCallback(leaderSwitchedCallbackFunc) {}
+func (*mockServiceDiscovery) AddLeaderSwitchedCallback(LeaderSwitchedCallbackFunc) {}
 
 // AddMembersChangedCallback implements the ServiceDiscovery interface.
 func (*mockServiceDiscovery) AddMembersChangedCallback(func()) {}

client/servicediscovery/service_discovery.go

@@ -130,11 +130,11 @@ type ServiceDiscovery interface {
 	// in a quorum-based cluster or among the primary/secondaries in a primary/secondary configured cluster.
 	CheckMemberChanged() error
 	// ExecAndAddLeaderSwitchedCallback executes the callback once and adds it to the callback list then.
-	ExecAndAddLeaderSwitchedCallback(cb leaderSwitchedCallbackFunc)
+	ExecAndAddLeaderSwitchedCallback(cb LeaderSwitchedCallbackFunc)
 	// AddLeaderSwitchedCallback adds callbacks which will be called when the leader
 	// in a quorum-based cluster or the primary in a primary/secondary configured cluster
 	// is switched.
-	AddLeaderSwitchedCallback(cb leaderSwitchedCallbackFunc)
+	AddLeaderSwitchedCallback(cb LeaderSwitchedCallbackFunc)
 	// AddMembersChangedCallback adds callbacks which will be called when any leader/follower
 	// in a quorum-based cluster or any primary/secondary in a primary/secondary configured cluster
 	// is changed.
@@ -780,7 +780,7 @@ func (c *serviceDiscovery) CheckMemberChanged() error {
 }
 
 // ExecAndAddLeaderSwitchedCallback executes the callback once and adds it to the callback list then.
-func (c *serviceDiscovery) ExecAndAddLeaderSwitchedCallback(callback leaderSwitchedCallbackFunc) {
+func (c *serviceDiscovery) ExecAndAddLeaderSwitchedCallback(callback LeaderSwitchedCallbackFunc) {
 	url := c.getLeaderURL()
 	if len(url) > 0 {
 		if err := callback(url); err != nil {
@@ -794,7 +794,7 @@ func (c *serviceDiscovery) ExecAndAddLeaderSwitchedCallback(callback leaderSwitc
 // AddLeaderSwitchedCallback adds callbacks which will be called when the leader
 // in a quorum-based cluster or the primary in a primary/secondary configured cluster
 // is switched.
-func (c *serviceDiscovery) AddLeaderSwitchedCallback(callback leaderSwitchedCallbackFunc) {
+func (c *serviceDiscovery) AddLeaderSwitchedCallback(callback LeaderSwitchedCallbackFunc) {
 	c.callbacks.addLeaderSwitchedCallback(callback)
 }
 

client/servicediscovery/tso_service_discovery.go

@@ -141,7 +141,7 @@
 	clientConns sync.Map // Store as map[string]*grpc.ClientConn
 
 	// tsoLeaderUpdatedCb will be called when the TSO leader is updated.
-	tsoLeaderUpdatedCb leaderSwitchedCallbackFunc
+	tsoLeaderUpdatedCb LeaderSwitchedCallbackFunc
 
 	checkMembershipCh chan struct{}
 
@@ -359,7 +359,7 @@
 }
 
 // ExecAndAddLeaderSwitchedCallback executes the callback once and adds it to the callback list then.
-func (c *tsoServiceDiscovery) ExecAndAddLeaderSwitchedCallback(callback leaderSwitchedCallbackFunc) {
+func (c *tsoServiceDiscovery) ExecAndAddLeaderSwitchedCallback(callback LeaderSwitchedCallbackFunc) {
 	url := c.getPrimaryURL()
 	if len(url) > 0 {
 		if err := callback(url); err != nil {
@@ -371,7 +371,7 @@
 
 // AddLeaderSwitchedCallback adds callbacks which will be called when the primary in
 // a primary/secondary configured cluster is switched.
-func (*tsoServiceDiscovery) AddLeaderSwitchedCallback(leaderSwitchedCallbackFunc) {}
+func (*tsoServiceDiscovery) AddLeaderSwitchedCallback(LeaderSwitchedCallbackFunc) {}
 
 // AddMembersChangedCallback adds callbacks which will be called when any primary/secondary
 // in a primary/secondary configured cluster is changed.