fix review comments

clientconn.go

@@ -439,7 +439,7 @@ func (cc *ClientConn) scWatcher() {
 			// We may revisit this decision in the future.
 			cc.sc = sc
 			s := ""
-			cc.scRaw = &s
+			cc.sc.rawJSONString = &s
 			cc.mu.Unlock()
 		case <-cc.ctx.Done():
 			return
@@ -479,8 +479,8 @@ func (cc *ClientConn) handleResolvedAddrs(addrs []resolver.Address, err error) {
 	}
 
 	// If resolver does not return service config, apply the default service config if available.
-	if cc.scRaw == nil && cc.dopts.defaultServiceConfig != nil {
-		cc.applyServiceConfig(cc.dopts.defaultServiceConfig, cc.dopts.defaultServiceConfigRaw)
+	if cc.sc.rawJSONString == nil && cc.dopts.defaultServiceConfig != nil {
+		cc.applyServiceConfig(cc.dopts.defaultServiceConfig, *cc.dopts.defaultServiceConfig.rawJSONString)
 	}
 
 	cc.curAddresses = addrs
@@ -770,11 +770,11 @@ func (cc *ClientConn) handleServiceConfig(js string) error {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
 	if cc.dopts.disableServiceConfig {
-		if cc.dopts.defaultServiceConfig == nil {
+		if cc.dopts.defaultServiceConfig == nil || cc.scRaw != nil {
 			return nil
 		}
 		// apply default service config when there's resolver service config is disabled.
-		return cc.applyServiceConfig(cc.dopts.defaultServiceConfig, cc.dopts.defaultServiceConfigRaw)
+		return cc.applyServiceConfig(cc.dopts.defaultServiceConfig, *cc.dopts.defaultServiceConfig.rawJSONString)
 	}
 
 	return cc.applyServiceConfig(nil, js)
@@ -784,7 +784,7 @@ func (cc *ClientConn) handleServiceConfig(js string) error {
 // a parsed service config, we will skip the parsing. It will also skip the whole processing if
 // the new service config is the same as the old one.
 func (cc *ClientConn) applyServiceConfig(sc *ServiceConfig, js string) error {
-	if cc.scRaw != nil && *cc.scRaw == js {
+	if cc.sc.rawJSONString != nil && *cc.sc.rawJSONString == js {
 		return nil
 	}
 
@@ -794,7 +794,7 @@ func (cc *ClientConn) applyServiceConfig(sc *ServiceConfig, js string) error {
 		if err != nil {
 			return err
 		}
-		sc = &scfg
+		sc = scfg
 	}
 
 	if channelz.IsOn() {
@@ -811,7 +811,7 @@ func (cc *ClientConn) applyServiceConfig(sc *ServiceConfig, js string) error {
 	if cc.conns == nil {
 		return nil
 	}
-	cc.scRaw = &js
+	sc.rawJSONString = &js
 	cc.sc = *sc
 
 	if sc.retryThrottling != nil {

dialoptions.go

@@ -55,15 +55,14 @@ type dialOptions struct {
 	// balancer, and also by WithBalancerName dial option.
 	balancerBuilder balancer.Builder
 	// This is to support grpclb.
-	resolverBuilder         resolver.Builder
-	reqHandshake            envconfig.RequireHandshakeSetting
-	channelzParentID        int64
-	disableServiceConfig    bool
-	disableRetry            bool
-	disableHealthCheck      bool
-	healthCheckFunc         internal.HealthChecker
-	defaultServiceConfig    *ServiceConfig
-	defaultServiceConfigRaw string
+	resolverBuilder      resolver.Builder
+	reqHandshake         envconfig.RequireHandshakeSetting
+	channelzParentID     int64
+	disableServiceConfig bool
+	disableRetry         bool
+	disableHealthCheck   bool
+	healthCheckFunc      internal.HealthChecker
+	defaultServiceConfig *ServiceConfig
 }
 
 // DialOption configures how we set up the connection.
@@ -452,15 +451,16 @@ func WithDisableServiceConfig() DialOption {
 // will be used in cases where:
 // 1. WithDisableServiceConfig is called.
 // 2. Resolver does not return service config or if the resolver gets and invalid config.
+// It is strongly recommended that caller of this function verifies the validity of the input string
+// by using the grpc.ValidateServiceConfig function.
 func WithDefaultServiceConfig(s string) DialOption {
 	return newFuncDialOption(func(o *dialOptions) {
 		sc, err := parseServiceConfig(s)
 		if err != nil {
 			grpclog.Warningf("the provided service config is invalid, err: %v", err)
 			return
 		}
-		o.defaultServiceConfig = &sc
-		o.defaultServiceConfigRaw = s
+		o.defaultServiceConfig = sc
 	})
 }
 

service_config.go

@@ -99,6 +99,10 @@ type ServiceConfig struct {
 	// healthCheckConfig must be set as one of the requirement to enable LB channel
 	// health check.
 	healthCheckConfig *healthCheckConfig
+	// rawJSONString stores the pointer to the original service config json string that get parsed into
+	// this service config struct. Null pointer means this is a service config struct just defined,
+	// but no json string has been parsed and initialize the struct.
+	rawJSONString *string
 }
 
 // healthCheckConfig defines the go-native version of the LB channel health check config.
@@ -238,12 +242,12 @@ type jsonSC struct {
 	HealthCheckConfig   *healthCheckConfig
 }
 
-func parseServiceConfig(js string) (ServiceConfig, error) {
+func parseServiceConfig(js string) (*ServiceConfig, error) {
 	var rsc jsonSC
 	err := json.Unmarshal([]byte(js), &rsc)
 	if err != nil {
 		grpclog.Warningf("grpc: parseServiceConfig error unmarshaling %s due to %v", js, err)
-		return ServiceConfig{}, err
+		return &ServiceConfig{}, err
 	}
 	sc := ServiceConfig{
 		LB:                rsc.LoadBalancingPolicy,
@@ -252,7 +256,7 @@ func parseServiceConfig(js string) (ServiceConfig, error) {
 		healthCheckConfig: rsc.HealthCheckConfig,
 	}
 	if rsc.MethodConfig == nil {
-		return sc, nil
+		return &sc, nil
 	}
 
 	for _, m := range *rsc.MethodConfig {
@@ -262,7 +266,7 @@ func parseServiceConfig(js string) (ServiceConfig, error) {
 		d, err := parseDuration(m.Timeout)
 		if err != nil {
 			grpclog.Warningf("grpc: parseServiceConfig error unmarshaling %s due to %v", js, err)
-			return ServiceConfig{}, err
+			return &ServiceConfig{}, err
 		}
 
 		mc := MethodConfig{
@@ -271,7 +275,7 @@ func parseServiceConfig(js string) (ServiceConfig, error) {
 		}
 		if mc.retryPolicy, err = convertRetryPolicy(m.RetryPolicy); err != nil {
 			grpclog.Warningf("grpc: parseServiceConfig error unmarshaling %s due to %v", js, err)
-			return ServiceConfig{}, err
+			return &ServiceConfig{}, err
 		}
 		if m.MaxRequestMessageBytes != nil {
 			if *m.MaxRequestMessageBytes > int64(maxInt) {
@@ -302,7 +306,8 @@ func parseServiceConfig(js string) (ServiceConfig, error) {
 			sc.retryThrottling = nil
 		}
 	}
-	return sc, nil
+	sc.rawJSONString = &js
+	return &sc, nil
 }
 
 func convertRetryPolicy(jrp *jsonRetryPolicy) (p *retryPolicy, err error) {

service_config_test.go

@@ -79,8 +79,8 @@ func (s) TestParseLoadBalancer(t *testing.T) {
 
 	for _, c := range testcases {
 		sc, err := parseServiceConfig(c.scjs)
-		if c.wantErr != (err != nil) || !reflect.DeepEqual(sc, c.wantSC) {
-			t.Fatalf("parseServiceConfig(%s) = %+v, %v, want %+v, %v", c.scjs, sc, err, c.wantSC, c.wantErr)
+		if c.wantErr != (err != nil) || !scCompareWithRawJSONSkipped(*sc, c.wantSC) {
+			t.Fatalf("parseServiceConfig(%s) = %+v, %v, want %+v, %v", c.scjs, *sc, err, c.wantSC, c.wantErr)
 		}
 	}
 }
@@ -167,7 +167,7 @@ func (s) TestParseWaitForReady(t *testing.T) {
 
 	for _, c := range testcases {
 		sc, err := parseServiceConfig(c.scjs)
-		if c.wantErr != (err != nil) || !reflect.DeepEqual(sc, c.wantSC) {
+		if c.wantErr != (err != nil) || !scCompareWithRawJSONSkipped(*sc, c.wantSC) {
 			t.Fatalf("parseServiceConfig(%s) = %+v, %v, want %+v, %v", c.scjs, sc, err, c.wantSC, c.wantErr)
 		}
 	}
@@ -249,7 +249,7 @@ func (s) TestPraseTimeOut(t *testing.T) {
 
 	for _, c := range testcases {
 		sc, err := parseServiceConfig(c.scjs)
-		if c.wantErr != (err != nil) || !reflect.DeepEqual(sc, c.wantSC) {
+		if c.wantErr != (err != nil) || !scCompareWithRawJSONSkipped(*sc, c.wantSC) {
 			t.Fatalf("parseServiceConfig(%s) = %+v, %v, want %+v, %v", c.scjs, sc, err, c.wantSC, c.wantErr)
 		}
 	}
@@ -318,7 +318,7 @@ func (s) TestPraseMsgSize(t *testing.T) {
 
 	for _, c := range testcases {
 		sc, err := parseServiceConfig(c.scjs)
-		if c.wantErr != (err != nil) || !reflect.DeepEqual(sc, c.wantSC) {
+		if c.wantErr != (err != nil) || !scCompareWithRawJSONSkipped(*sc, c.wantSC) {
 			t.Fatalf("parseServiceConfig(%s) = %+v, %v, want %+v, %v", c.scjs, sc, err, c.wantSC, c.wantErr)
 		}
 	}
@@ -384,3 +384,9 @@ func newDuration(b time.Duration) *time.Duration {
 func newString(b string) *string {
 	return &b
 }
+
+func scCompareWithRawJSONSkipped(s1, s2 ServiceConfig) bool {
+	s1.rawJSONString = nil
+	s2.rawJSONString = nil
+	return reflect.DeepEqual(s1, s2)
+}