client: support use API context to create client (tikv#6482)

ref tikv#6142

Signed-off-by: Ryan Leung <rleungx@gmail.com>

client/client.go

@@ -52,6 +52,7 @@ const (
 	// defaultKeySpaceGroupID is the default key space group id.
 	// We also reserved 0 for the keyspace group for the same purpose.
 	defaultKeySpaceGroupID = uint32(0)
+	defaultKeyspaceName    = "DEFAULT"
 )
 
 // Region contains information of a region's meta and its peers.
@@ -321,6 +322,7 @@ func NewClientWithContext(
 }
 
 // NewClientWithKeyspace creates a client with context and the specified keyspace id.
+// And now, it's only for test purpose.
 func NewClientWithKeyspace(
 	ctx context.Context, keyspaceID uint32, svrAddrs []string,
 	security SecurityOption, opts ...ClientOption,
@@ -374,19 +376,87 @@ func createClientWithKeyspace(
 	return c, nil
 }
 
-// NewClientWithKeyspaceName creates a client with context and the specified keyspace name.
-func NewClientWithKeyspaceName(
+// APIVersion is the API version the server and the client is using.
+// See more details in https://github.com/tikv/rfcs/blob/master/text/0069-api-v2.md#kvproto
+type APIVersion int
+
+// The API versions the client supports.
+// As for V1TTL, client won't use it and we just remove it.
+const (
+	V1 APIVersion = iota
+	_
+	V2
+)
+
+// APIContext is the context for API version.
+type APIContext interface {
+	GetAPIVersion() (apiVersion APIVersion)
+	GetKeyspaceName() (keyspaceName string)
+}
+
+type apiContextV1 struct{}
+
+// NewAPIContextV1 creates a API context for V1.
+func NewAPIContextV1() APIContext {
+	return &apiContextV1{}
+}
+
+// GetAPIVersion returns the API version.
+func (apiCtx *apiContextV1) GetAPIVersion() (version APIVersion) {
+	return V1
+}
+
+// GetKeyspaceName returns the keyspace name.
+func (apiCtx *apiContextV1) GetKeyspaceName() (keyspaceName string) {
+	return ""
+}
+
+type apiContextV2 struct {
+	keyspaceName string
+}
+
+// NewAPIContextV2 creates a API context with the specified keyspace name for V2.
+func NewAPIContextV2(keyspaceName string) APIContext {
+	if len(keyspaceName) == 0 {
+		keyspaceName = defaultKeyspaceName
+	}
+	return &apiContextV2{keyspaceName: keyspaceName}
+}
+
+// GetAPIVersion returns the API version.
+func (apiCtx *apiContextV2) GetAPIVersion() (version APIVersion) {
+	return V2
+}
+
+// GetKeyspaceName returns the keyspace name.
+func (apiCtx *apiContextV2) GetKeyspaceName() (keyspaceName string) {
+	return apiCtx.keyspaceName
+}
+
+// NewClientWithAPIContext creates a client according to the API context.
+func NewClientWithAPIContext(
+	ctx context.Context, apiCtx APIContext, svrAddrs []string,
+	security SecurityOption, opts ...ClientOption,
+) (Client, error) {
+	apiVersion, keyspaceName := apiCtx.GetAPIVersion(), apiCtx.GetKeyspaceName()
+	switch apiVersion {
+	case V1:
+		return NewClientWithContext(ctx, svrAddrs, security, opts...)
+	case V2:
+		return newClientWithKeyspaceName(ctx, keyspaceName, svrAddrs, security, opts...)
+	default:
+		return nil, errors.Errorf("[pd] invalid API version %d", apiVersion)
+	}
+}
+
+// newClientWithKeyspaceName creates a client with context and the specified keyspace name.
+func newClientWithKeyspaceName(
 	ctx context.Context, keyspaceName string, svrAddrs []string,
 	security SecurityOption, opts ...ClientOption,
 ) (Client, error) {
 	log.Info("[pd] create pd client with endpoints and keyspace",
 		zap.Strings("pd-address", svrAddrs), zap.String("keyspace-name", keyspaceName))
 
-	// if keyspace name is empty, fall back to the legacy API
-	if len(keyspaceName) == 0 {
-		return NewClientWithContext(ctx, svrAddrs, security, opts...)
-	}
-
 	tlsCfg := &tlsutil.TLSConfig{
 		CAPath:   security.CAPath,
 		CertPath: security.CertPath,

tests/integrations/mcs/testutil.go

@@ -48,11 +48,11 @@ func InitLogger(cfg *tso.Config) (err error) {
 	return err
 }
 
-// SetupClientWithDefaultKeyspaceName creates a TSO client with default keyspace name for test.
-func SetupClientWithDefaultKeyspaceName(
-	ctx context.Context, re *require.Assertions, endpoints []string, opts ...pd.ClientOption,
+// SetupClientWithAPIContext creates a TSO client with api context name for test.
+func SetupClientWithAPIContext(
+	ctx context.Context, re *require.Assertions, apiCtx pd.APIContext, endpoints []string, opts ...pd.ClientOption,
 ) pd.Client {
-	cli, err := pd.NewClientWithKeyspaceName(ctx, "", endpoints, pd.SecurityOption{}, opts...)
+	cli, err := pd.NewClientWithAPIContext(ctx, apiCtx, endpoints, pd.SecurityOption{}, opts...)
 	re.NoError(err)
 	return cli
 }

tests/integrations/mcs/tso/server_test.go

@@ -189,7 +189,7 @@ func checkTSOPath(re *require.Assertions, isAPIServiceMode bool) {
 	_, cleanup := mcs.StartSingleTSOTestServer(ctx, re, backendEndpoints, tempurl.Alloc())
 	defer cleanup()
 
-	cli := mcs.SetupClientWithDefaultKeyspaceName(ctx, re, []string{backendEndpoints})
+	cli := mcs.SetupClientWithAPIContext(ctx, re, pd.NewAPIContextV2(""), []string{backendEndpoints})
 	physical, logical, err := cli.GetTS(ctx)
 	re.NoError(err)
 	ts := tsoutil.ComposeTS(physical, logical)

tests/integrations/tso/client_test.go

@@ -456,7 +456,7 @@ func checkTSO(ctx context.Context, re *require.Assertions, wg *sync.WaitGroup, b
 	for i := 0; i < tsoRequestConcurrencyNumber; i++ {
 		go func() {
 			defer wg.Done()
-			cli := mcs.SetupClientWithDefaultKeyspaceName(ctx, re, strings.Split(backendEndpoints, ","))
+			cli := mcs.SetupClientWithAPIContext(ctx, re, pd.NewAPIContextV1(), strings.Split(backendEndpoints, ","))
 			var ts, lastTS uint64
 			for {
 				select {