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Diffstat (limited to 'vendor/google.golang.org/grpc/service_config.go')
-rw-r--r-- | vendor/google.golang.org/grpc/service_config.go | 454 |
1 files changed, 454 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/service_config.go b/vendor/google.golang.org/grpc/service_config.go new file mode 100644 index 000000000..5e434ca7f --- /dev/null +++ b/vendor/google.golang.org/grpc/service_config.go @@ -0,0 +1,454 @@ +/* + * + * 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 struct { + // WaitForReady indicates whether RPCs sent to this method should wait until + // the connection is ready by default (!failfast). The value specified via the + // gRPC client API will override the value set here. + WaitForReady *bool + // Timeout is the default timeout for RPCs sent to this method. The actual + // deadline used will be the minimum of the value specified here and the value + // set by the application via the gRPC client API. If either one is not set, + // then the other will be used. If neither is set, then the RPC has no deadline. + Timeout *time.Duration + // MaxReqSize is the maximum allowed payload size for an individual request in a + // stream (client->server) in bytes. The size which is measured is the serialized + // payload after per-message compression (but before stream compression) in bytes. + // The actual value used is the minimum of the value specified here and the value set + // by the application via the gRPC client API. If either one is not set, then the other + // will be used. If neither is set, then the built-in default is used. + MaxReqSize *int + // MaxRespSize is the maximum allowed payload size for an individual response in a + // stream (server->client) in bytes. + MaxRespSize *int + // RetryPolicy configures retry options for the method. + 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. +// +// 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. The balancer + // specified via grpc.WithBalancerName 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 + // 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 +} + +// retryPolicy defines the go-native version of the retry policy defined by the +// service config here: +// https://github.com/grpc/proposal/blob/master/A6-client-retries.md#integration-with-service-config +type retryPolicy struct { + // MaxAttempts is the maximum number of attempts, including the original RPC. + // + // This field is required and must be two or greater. + maxAttempts int + + // Exponential backoff parameters. The initial retry attempt will occur at + // random(0, initialBackoff). In general, the nth attempt will occur at + // random(0, + // min(initialBackoff*backoffMultiplier**(n-1), maxBackoff)). + // + // These fields are required and must be greater than zero. + initialBackoff time.Duration + maxBackoff time.Duration + backoffMultiplier float64 + + // The set of status codes which may be retried. + // + // Status codes are specified as strings, e.g., "UNAVAILABLE". + // + // This field is required and must be non-empty. + // Note: a set is used to store this for easy lookup. + retryableStatusCodes map[codes.Code]bool +} + +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.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 { + logger.Warningf("grpc: parseServiceConfig error unmarshaling %s due to %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: parseServiceConfig error unmarshaling %s due to %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: parseServiceConfig error unmarshaling %s due to %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: parseServiceConfig error unmarshaling %s due to methodConfig[%d]: %v", js, i, err) + return &serviceconfig.ParseResult{Err: err} + } + + if _, ok := paths[path]; ok { + err = errDuplicatedName + logger.Warningf("grpc: parseServiceConfig error unmarshaling %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 *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 := &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 { + 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) +} |