| /* |
| * 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 ( |
| "reflect" |
| "sync" |
| ) |
| |
| import ( |
| "github.com/apache/dubbo-go/common/extension" |
| "github.com/apache/dubbo-go/common/observer" |
| ) |
| |
| func init() { |
| extension.AddEventListener(GetCustomizableServiceInstanceListener) |
| } |
| |
| // customizableServiceInstanceListener is singleton |
| type customizableServiceInstanceListener struct{} |
| |
| // GetPriority return priority 9999, |
| // 9999 is big enough to make sure it will be last invoked |
| func (c *customizableServiceInstanceListener) GetPriority() int { |
| return 9999 |
| } |
| |
| // OnEvent if the event is ServiceInstancePreRegisteredEvent |
| // it will iterate all ServiceInstanceCustomizer instances |
| // or it will do nothing |
| func (c *customizableServiceInstanceListener) OnEvent(e observer.Event) error { |
| if preRegEvent, ok := e.(*ServiceInstancePreRegisteredEvent); ok { |
| for _, cus := range extension.GetCustomizers() { |
| cus.Customize(preRegEvent.serviceInstance) |
| } |
| } |
| return nil |
| } |
| |
| // GetEventType will return ServiceInstancePreRegisteredEvent |
| func (c *customizableServiceInstanceListener) GetEventType() reflect.Type { |
| return reflect.TypeOf(&ServiceInstancePreRegisteredEvent{}) |
| } |
| |
| var ( |
| customizableServiceInstanceListenerInstance *customizableServiceInstanceListener |
| customizableServiceInstanceListenerOnce sync.Once |
| ) |
| |
| // GetCustomizableServiceInstanceListener returns an instance |
| // if the instance was not initialized, we create one |
| func GetCustomizableServiceInstanceListener() observer.EventListener { |
| customizableServiceInstanceListenerOnce.Do(func() { |
| customizableServiceInstanceListenerInstance = &customizableServiceInstanceListener{} |
| }) |
| return customizableServiceInstanceListenerInstance |
| } |