Add unit tests

vendor/google.golang.org/grpc/service_config.go

@@ -25,8 +25,11 @@ import (
 	"strings"
 	"time"
 
+	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/serviceconfig"
 )
 
 const maxInt = int(^uint(0) >> 1)
@@ -61,6 +64,11 @@ type MethodConfig struct {
 	retryPolicy *retryPolicy
 }
 
+type lbConfig struct {
+	name string
+	cfg  serviceconfig.LoadBalancingConfig
+}
+
 // ServiceConfig is provided by the service provider and contains parameters for how
 // clients that connect to the service should behave.
 //
@@ -68,10 +76,18 @@ type MethodConfig struct {
 // through name resolver, as specified here
 // https://github.com/grpc/grpc/blob/master/doc/service_config.md
 type ServiceConfig struct {
-	// LB is the load balancer the service providers recommends. The balancer specified
-	// via grpc.WithBalancer will override this.
+	serviceconfig.Config
+
+	// LB is the load balancer the service providers recommends. The balancer
+	// specified via grpc.WithBalancer will override this.  This is deprecated;
+	// lbConfigs is preferred.  If lbConfig and LB are both present, lbConfig
+	// will be used.
 	LB *string
 
+	// lbConfig is the service config's load balancing configuration.  If
+	// lbConfig and LB are both present, lbConfig will be used.
+	lbConfig *lbConfig
+
 	// Methods contains a map for the methods in this service.  If there is an
 	// exact match for a method (i.e. /service/method) in the map, use the
 	// corresponding MethodConfig.  If there's no exact match, look for the
@@ -96,6 +112,18 @@ type ServiceConfig struct {
 	// If token_count is less than or equal to maxTokens / 2, then RPCs will not
 	// be retried and hedged RPCs will not be sent.
 	retryThrottling *retryThrottlingPolicy
+	// healthCheckConfig must be set as one of the requirement to enable LB channel
+	// health check.
+	healthCheckConfig *healthCheckConfig
+	// rawJSONString stores service config json string that get parsed into
+	// this service config struct.
+	rawJSONString string
+}
+
+// healthCheckConfig defines the go-native version of the LB channel health check config.
+type healthCheckConfig struct {
+	// serviceName is the service name to use in the health-checking request.
+	ServiceName string
 }
 
 // retryPolicy defines the go-native version of the retry policy defined by the
@@ -108,9 +136,9 @@ type retryPolicy struct {
 	maxAttempts int
 
 	// Exponential backoff parameters. The initial retry attempt will occur at
-	// random(0, initialBackoffMS). In general, the nth attempt will occur at
+	// random(0, initialBackoff). In general, the nth attempt will occur at
 	// random(0,
-	//   min(initialBackoffMS*backoffMultiplier**(n-1), maxBackoffMS)).
+	//   min(initialBackoff*backoffMultiplier**(n-1), maxBackoff)).
 	//
 	// These fields are required and must be greater than zero.
 	initialBackoff    time.Duration
@@ -221,29 +249,77 @@ type jsonMC struct {
 	RetryPolicy             *jsonRetryPolicy
 }
 
+type loadBalancingConfig map[string]json.RawMessage
+
 // TODO(lyuxuan): delete this struct after cleaning up old service config implementation.
 type jsonSC struct {
 	LoadBalancingPolicy *string
+	LoadBalancingConfig *[]loadBalancingConfig
 	MethodConfig        *[]jsonMC
 	RetryThrottling     *retryThrottlingPolicy
+	HealthCheckConfig   *healthCheckConfig
 }
 
-func parseServiceConfig(js string) (ServiceConfig, error) {
+func init() {
+	internal.ParseServiceConfigForTesting = parseServiceConfig
+}
+func parseServiceConfig(js string) *serviceconfig.ParseResult {
+	if len(js) == 0 {
+		return &serviceconfig.ParseResult{Err: fmt.Errorf("no JSON service config provided")}
+	}
 	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.ParseResult{Err: err}
 	}
 	sc := ServiceConfig{
-		LB:              rsc.LoadBalancingPolicy,
-		Methods:         make(map[string]MethodConfig),
-		retryThrottling: rsc.RetryThrottling,
+		LB:                rsc.LoadBalancingPolicy,
+		Methods:           make(map[string]MethodConfig),
+		retryThrottling:   rsc.RetryThrottling,
+		healthCheckConfig: rsc.HealthCheckConfig,
+		rawJSONString:     js,
 	}
-	if rsc.MethodConfig == nil {
-		return sc, nil
+	if rsc.LoadBalancingConfig != nil {
+		for i, lbcfg := range *rsc.LoadBalancingConfig {
+			if len(lbcfg) != 1 {
+				err := fmt.Errorf("invalid loadBalancingConfig: entry %v does not contain exactly 1 policy/config pair: %q", i, lbcfg)
+				grpclog.Warningf(err.Error())
+				return &serviceconfig.ParseResult{Err: err}
+			}
+			var name string
+			var jsonCfg json.RawMessage
+			for name, jsonCfg = range lbcfg {
+			}
+			builder := balancer.Get(name)
+			if builder == nil {
+				continue
+			}
+			sc.lbConfig = &lbConfig{name: name}
+			if parser, ok := builder.(balancer.ConfigParser); ok {
+				var err error
+				sc.lbConfig.cfg, err = parser.ParseConfig(jsonCfg)
+				if err != nil {
+					return &serviceconfig.ParseResult{Err: fmt.Errorf("error parsing loadBalancingConfig for policy %q: %v", name, err)}
+				}
+			} else if string(jsonCfg) != "{}" {
+				grpclog.Warningf("non-empty balancer configuration %q, but balancer does not implement ParseConfig", string(jsonCfg))
+			}
+			break
+		}
+		if sc.lbConfig == nil {
+			// We had a loadBalancingConfig field but did not encounter a
+			// supported policy.  The config is considered invalid in this
+			// case.
+			err := fmt.Errorf("invalid loadBalancingConfig: no supported policies found")
+			grpclog.Warningf(err.Error())
+			return &serviceconfig.ParseResult{Err: err}
+		}
 	}
 
+	if rsc.MethodConfig == nil {
+		return &serviceconfig.ParseResult{Config: &sc}
+	}
 	for _, m := range *rsc.MethodConfig {
 		if m.Name == nil {
 			continue
@@ -251,7 +327,7 @@ 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.ParseResult{Err: err}
 		}
 
 		mc := MethodConfig{
@@ -260,7 +336,7 @@ 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.ParseResult{Err: err}
 		}
 		if m.MaxRequestMessageBytes != nil {
 			if *m.MaxRequestMessageBytes > int64(maxInt) {
@@ -284,14 +360,14 @@ func parseServiceConfig(js string) (ServiceConfig, error) {
 	}
 
 	if sc.retryThrottling != nil {
-		if sc.retryThrottling.MaxTokens <= 0 ||
-			sc.retryThrottling.MaxTokens >= 1000 ||
-			sc.retryThrottling.TokenRatio <= 0 {
-			// Illegal throttling config; disable throttling.
-			sc.retryThrottling = nil
+		if mt := sc.retryThrottling.MaxTokens; mt <= 0 || mt > 1000 {
+			return &serviceconfig.ParseResult{Err: fmt.Errorf("invalid retry throttling config: maxTokens (%v) out of range (0, 1000]", mt)}
+		}
+		if tr := sc.retryThrottling.TokenRatio; tr <= 0 {
+			return &serviceconfig.ParseResult{Err: fmt.Errorf("invalid retry throttling config: tokenRatio (%v) may not be negative", tr)}
 		}
 	}
-	return sc, nil
+	return &serviceconfig.ParseResult{Config: &sc}
 }
 
 func convertRetryPolicy(jrp *jsonRetryPolicy) (p *retryPolicy, err error) {