feat: initial tracing support (#1623)

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

@@ -0,0 +1,406 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpc
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/internal"
+	internalserviceconfig "google.golang.org/grpc/internal/serviceconfig"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+const maxInt = int(^uint(0) >> 1)
+
+// MethodConfig defines the configuration recommended by the service providers for a
+// particular method.
+//
+// Deprecated: Users should not use this struct. Service config should be received
+// through name resolver, as specified here
+// https://github.com/grpc/grpc/blob/master/doc/service_config.md
+type MethodConfig = internalserviceconfig.MethodConfig
+
+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.
+//
+// Deprecated: Users should not use this struct. Service config should be received
+// through name resolver, as specified here
+// https://github.com/grpc/grpc/blob/master/doc/service_config.md
+type ServiceConfig struct {
+	serviceconfig.Config
+
+	// LB is the load balancer the service providers recommends.  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
+	// default config for the service (/service/) and use the corresponding
+	// MethodConfig if it exists.  Otherwise, the method has no MethodConfig to
+	// use.
+	Methods map[string]MethodConfig
+
+	// If a retryThrottlingPolicy is provided, gRPC will automatically throttle
+	// retry attempts and hedged RPCs when the client’s ratio of failures to
+	// successes exceeds a threshold.
+	//
+	// For each server name, the gRPC client will maintain a token_count which is
+	// initially set to maxTokens, and can take values between 0 and maxTokens.
+	//
+	// Every outgoing RPC (regardless of service or method invoked) will change
+	// token_count as follows:
+	//
+	//   - Every failed RPC will decrement the token_count by 1.
+	//   - Every successful RPC will increment the token_count by tokenRatio.
+	//
+	// 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
+}
+
+type jsonRetryPolicy struct {
+	MaxAttempts          int
+	InitialBackoff       string
+	MaxBackoff           string
+	BackoffMultiplier    float64
+	RetryableStatusCodes []codes.Code
+}
+
+// retryThrottlingPolicy defines the go-native version of the retry throttling
+// policy defined by the service config here:
+// https://github.com/grpc/proposal/blob/master/A6-client-retries.md#integration-with-service-config
+type retryThrottlingPolicy struct {
+	// The number of tokens starts at maxTokens. The token_count will always be
+	// between 0 and maxTokens.
+	//
+	// This field is required and must be greater than zero.
+	MaxTokens float64
+	// The amount of tokens to add on each successful RPC. Typically this will
+	// be some number between 0 and 1, e.g., 0.1.
+	//
+	// This field is required and must be greater than zero. Up to 3 decimal
+	// places are supported.
+	TokenRatio float64
+}
+
+func parseDuration(s *string) (*time.Duration, error) {
+	if s == nil {
+		return nil, nil
+	}
+	if !strings.HasSuffix(*s, "s") {
+		return nil, fmt.Errorf("malformed duration %q", *s)
+	}
+	ss := strings.SplitN((*s)[:len(*s)-1], ".", 3)
+	if len(ss) > 2 {
+		return nil, fmt.Errorf("malformed duration %q", *s)
+	}
+	// hasDigits is set if either the whole or fractional part of the number is
+	// present, since both are optional but one is required.
+	hasDigits := false
+	var d time.Duration
+	if len(ss[0]) > 0 {
+		i, err := strconv.ParseInt(ss[0], 10, 32)
+		if err != nil {
+			return nil, fmt.Errorf("malformed duration %q: %v", *s, err)
+		}
+		d = time.Duration(i) * time.Second
+		hasDigits = true
+	}
+	if len(ss) == 2 && len(ss[1]) > 0 {
+		if len(ss[1]) > 9 {
+			return nil, fmt.Errorf("malformed duration %q", *s)
+		}
+		f, err := strconv.ParseInt(ss[1], 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("malformed duration %q: %v", *s, err)
+		}
+		for i := 9; i > len(ss[1]); i-- {
+			f *= 10
+		}
+		d += time.Duration(f)
+		hasDigits = true
+	}
+	if !hasDigits {
+		return nil, fmt.Errorf("malformed duration %q", *s)
+	}
+
+	return &d, nil
+}
+
+type jsonName struct {
+	Service string
+	Method  string
+}
+
+var (
+	errDuplicatedName             = errors.New("duplicated name")
+	errEmptyServiceNonEmptyMethod = errors.New("cannot combine empty 'service' and non-empty 'method'")
+)
+
+func (j jsonName) generatePath() (string, error) {
+	if j.Service == "" {
+		if j.Method != "" {
+			return "", errEmptyServiceNonEmptyMethod
+		}
+		return "", nil
+	}
+	res := "/" + j.Service + "/"
+	if j.Method != "" {
+		res += j.Method
+	}
+	return res, nil
+}
+
+// TODO(lyuxuan): delete this struct after cleaning up old service config implementation.
+type jsonMC struct {
+	Name                    *[]jsonName
+	WaitForReady            *bool
+	Timeout                 *string
+	MaxRequestMessageBytes  *int64
+	MaxResponseMessageBytes *int64
+	RetryPolicy             *jsonRetryPolicy
+}
+
+// TODO(lyuxuan): delete this struct after cleaning up old service config implementation.
+type jsonSC struct {
+	LoadBalancingPolicy *string
+	LoadBalancingConfig *internalserviceconfig.BalancerConfig
+	MethodConfig        *[]jsonMC
+	RetryThrottling     *retryThrottlingPolicy
+	HealthCheckConfig   *healthCheckConfig
+}
+
+func init() {
+	internal.ParseServiceConfig = 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 {
+		logger.Warningf("grpc: unmarshaling service config %s: %v", js, err)
+		return &serviceconfig.ParseResult{Err: err}
+	}
+	sc := ServiceConfig{
+		LB:                rsc.LoadBalancingPolicy,
+		Methods:           make(map[string]MethodConfig),
+		retryThrottling:   rsc.RetryThrottling,
+		healthCheckConfig: rsc.HealthCheckConfig,
+		rawJSONString:     js,
+	}
+	if c := rsc.LoadBalancingConfig; c != nil {
+		sc.lbConfig = &lbConfig{
+			name: c.Name,
+			cfg:  c.Config,
+		}
+	}
+
+	if rsc.MethodConfig == nil {
+		return &serviceconfig.ParseResult{Config: &sc}
+	}
+
+	paths := map[string]struct{}{}
+	for _, m := range *rsc.MethodConfig {
+		if m.Name == nil {
+			continue
+		}
+		d, err := parseDuration(m.Timeout)
+		if err != nil {
+			logger.Warningf("grpc: unmarshaling service config %s: %v", js, err)
+			return &serviceconfig.ParseResult{Err: err}
+		}
+
+		mc := MethodConfig{
+			WaitForReady: m.WaitForReady,
+			Timeout:      d,
+		}
+		if mc.RetryPolicy, err = convertRetryPolicy(m.RetryPolicy); err != nil {
+			logger.Warningf("grpc: unmarshaling service config %s: %v", js, err)
+			return &serviceconfig.ParseResult{Err: err}
+		}
+		if m.MaxRequestMessageBytes != nil {
+			if *m.MaxRequestMessageBytes > int64(maxInt) {
+				mc.MaxReqSize = newInt(maxInt)
+			} else {
+				mc.MaxReqSize = newInt(int(*m.MaxRequestMessageBytes))
+			}
+		}
+		if m.MaxResponseMessageBytes != nil {
+			if *m.MaxResponseMessageBytes > int64(maxInt) {
+				mc.MaxRespSize = newInt(maxInt)
+			} else {
+				mc.MaxRespSize = newInt(int(*m.MaxResponseMessageBytes))
+			}
+		}
+		for i, n := range *m.Name {
+			path, err := n.generatePath()
+			if err != nil {
+				logger.Warningf("grpc: error unmarshaling service config %s due to methodConfig[%d]: %v", js, i, err)
+				return &serviceconfig.ParseResult{Err: err}
+			}
+
+			if _, ok := paths[path]; ok {
+				err = errDuplicatedName
+				logger.Warningf("grpc: error unmarshaling service config %s due to methodConfig[%d]: %v", js, i, err)
+				return &serviceconfig.ParseResult{Err: err}
+			}
+			paths[path] = struct{}{}
+			sc.Methods[path] = mc
+		}
+	}
+
+	if 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 &serviceconfig.ParseResult{Config: &sc}
+}
+
+func convertRetryPolicy(jrp *jsonRetryPolicy) (p *internalserviceconfig.RetryPolicy, err error) {
+	if jrp == nil {
+		return nil, nil
+	}
+	ib, err := parseDuration(&jrp.InitialBackoff)
+	if err != nil {
+		return nil, err
+	}
+	mb, err := parseDuration(&jrp.MaxBackoff)
+	if err != nil {
+		return nil, err
+	}
+
+	if jrp.MaxAttempts <= 1 ||
+		*ib <= 0 ||
+		*mb <= 0 ||
+		jrp.BackoffMultiplier <= 0 ||
+		len(jrp.RetryableStatusCodes) == 0 {
+		logger.Warningf("grpc: ignoring retry policy %v due to illegal configuration", jrp)
+		return nil, nil
+	}
+
+	rp := &internalserviceconfig.RetryPolicy{
+		MaxAttempts:          jrp.MaxAttempts,
+		InitialBackoff:       *ib,
+		MaxBackoff:           *mb,
+		BackoffMultiplier:    jrp.BackoffMultiplier,
+		RetryableStatusCodes: make(map[codes.Code]bool),
+	}
+	if rp.MaxAttempts > 5 {
+		// TODO(retry): Make the max maxAttempts configurable.
+		rp.MaxAttempts = 5
+	}
+	for _, code := range jrp.RetryableStatusCodes {
+		rp.RetryableStatusCodes[code] = true
+	}
+	return rp, nil
+}
+
+func min(a, b *int) *int {
+	if *a < *b {
+		return a
+	}
+	return b
+}
+
+func getMaxSize(mcMax, doptMax *int, defaultVal int) *int {
+	if mcMax == nil && doptMax == nil {
+		return &defaultVal
+	}
+	if mcMax != nil && doptMax != nil {
+		return min(mcMax, doptMax)
+	}
+	if mcMax != nil {
+		return mcMax
+	}
+	return doptMax
+}
+
+func newInt(b int) *int {
+	return &b
+}
+
+func init() {
+	internal.EqualServiceConfigForTesting = equalServiceConfig
+}
+
+// equalServiceConfig compares two configs. The rawJSONString field is ignored,
+// because they may diff in white spaces.
+//
+// If any of them is NOT *ServiceConfig, return false.
+func equalServiceConfig(a, b serviceconfig.Config) bool {
+	if a == nil && b == nil {
+		return true
+	}
+	aa, ok := a.(*ServiceConfig)
+	if !ok {
+		return false
+	}
+	bb, ok := b.(*ServiceConfig)
+	if !ok {
+		return false
+	}
+	aaRaw := aa.rawJSONString
+	aa.rawJSONString = ""
+	bbRaw := bb.rawJSONString
+	bb.rawJSONString = ""
+	defer func() {
+		aa.rawJSONString = aaRaw
+		bb.rawJSONString = bbRaw
+	}()
+	// Using reflect.DeepEqual instead of cmp.Equal because many balancer
+	// configs are unexported, and cmp.Equal cannot compare unexported fields
+	// from unexported structs.
+	return reflect.DeepEqual(aa, bb)
+}