| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 event |
| |
| import ( |
| "fmt" |
| "hash/crc32" |
| "sort" |
| ) |
| |
| import ( |
| "github.com/dubbogo/gost/log/logger" |
| ) |
| |
| import ( |
| "dubbo.apache.org/dubbo-go/v3/common" |
| "dubbo.apache.org/dubbo-go/v3/common/constant" |
| "dubbo.apache.org/dubbo-go/v3/common/extension" |
| "dubbo.apache.org/dubbo-go/v3/metadata/service/local" |
| "dubbo.apache.org/dubbo-go/v3/registry" |
| ) |
| |
| const defaultRevision = "N/A" |
| |
| func init() { |
| extension.AddCustomizers(&exportedServicesRevisionMetadataCustomizer{}) |
| extension.AddCustomizers(&subscribedServicesRevisionMetadataCustomizer{}) |
| } |
| |
| type exportedServicesRevisionMetadataCustomizer struct{} |
| |
| // GetPriority will return 1 so that it will be invoked in front of user defining Customizer |
| func (e *exportedServicesRevisionMetadataCustomizer) GetPriority() int { |
| return 1 |
| } |
| |
| // Customize calculate the revision for exported urls and then put it into instance metadata |
| func (e *exportedServicesRevisionMetadataCustomizer) Customize(instance registry.ServiceInstance) { |
| ms, err := local.GetLocalMetadataService() |
| if err != nil { |
| logger.Errorf("could not get metadata service", err) |
| return |
| } |
| |
| urls, err := ms.GetExportedURLs(constant.AnyValue, constant.AnyValue, constant.AnyValue, constant.AnyValue) |
| if err != nil { |
| logger.Errorf("could not find the exported url", err) |
| } |
| |
| revision := resolveRevision(urls) |
| if len(revision) == 0 { |
| revision = defaultRevision |
| } |
| instance.GetMetadata()[constant.ExportedServicesRevisionPropertyName] = revision |
| } |
| |
| type subscribedServicesRevisionMetadataCustomizer struct{} |
| |
| // GetPriority will return 2 so that it will be invoked in front of user defining Customizer |
| func (e *subscribedServicesRevisionMetadataCustomizer) GetPriority() int { |
| return 2 |
| } |
| |
| // Customize calculate the revision for subscribed urls and then put it into instance metadata |
| func (e *subscribedServicesRevisionMetadataCustomizer) Customize(instance registry.ServiceInstance) { |
| ms, err := local.GetLocalMetadataService() |
| if err != nil { |
| logger.Errorf("could not get metadata service", err) |
| return |
| } |
| |
| urls, err := ms.GetSubscribedURLs() |
| if err != nil { |
| logger.Errorf("could not find the subscribed url", err) |
| } |
| |
| revision := resolveRevision(urls) |
| if len(revision) == 0 { |
| revision = defaultRevision |
| } |
| instance.GetMetadata()[constant.SubscribedServicesRevisionPropertyName] = revision |
| } |
| |
| // resolveRevision is different from Dubbo because golang doesn't support overload |
| // so that we could use interface + method name as identifier and ignore the method params |
| // per my understanding, it's enough because Dubbo actually ignore the url params. |
| // please refer org.apache.dubbo.common.URL#toParameterString(java.lang.String...) |
| func resolveRevision(urls []*common.URL) string { |
| if len(urls) == 0 { |
| return "0" |
| } |
| candidates := make([]string, 0, len(urls)) |
| |
| for _, u := range urls { |
| sk := u.GetParam(constant.InterfaceKey, "") |
| |
| if len(u.Methods) == 0 { |
| candidates = append(candidates, sk) |
| } else { |
| for _, m := range u.Methods { |
| // methods are part of candidates |
| candidates = append(candidates, sk+constant.KeySeparator+m) |
| } |
| } |
| |
| // append url params if we need it |
| } |
| sort.Strings(candidates) |
| |
| // it's nearly impossible to be overflow |
| res := uint64(0) |
| for _, c := range candidates { |
| res += uint64(crc32.ChecksumIEEE([]byte(c))) |
| } |
| return fmt.Sprint(res) |
| } |