gtsocial-umbx

service_config.go (11942B)

---

 /*
  *
  * 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)
 }