| /* |
| * 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 cluster |
| |
| import ( |
| "context" |
| "sync" |
| ) |
| |
| import ( |
| "dubbo.apache.org/dubbo-go/v3/common" |
| "dubbo.apache.org/dubbo-go/v3/protocol" |
| ) |
| |
| var ( |
| lock sync.RWMutex |
| interceptors = make(map[string]func() Interceptor) |
| ) |
| |
| // SetClusterInterceptor sets cluster interceptor so that user has chance to inject extra logics before and after |
| // cluster invoker |
| func SetClusterInterceptor(name string, fun func() Interceptor) { |
| lock.Lock() |
| defer lock.Unlock() |
| interceptors[name] = fun |
| } |
| |
| // GetClusterInterceptor returns the cluster interceptor instance with the given name |
| func GetClusterInterceptor(name string) Interceptor { |
| lock.RLock() |
| defer lock.RUnlock() |
| if interceptors[name] == nil { |
| panic("cluster_interceptor for " + name + " doesn't exist, make sure the corresponding package is imported") |
| } |
| return interceptors[name]() |
| } |
| |
| // GetClusterInterceptors returns all instances of registered cluster interceptors |
| func GetClusterInterceptors() []Interceptor { |
| lock.RLock() |
| defer lock.RUnlock() |
| ret := make([]Interceptor, 0, len(interceptors)) |
| for _, f := range interceptors { |
| ret = append(ret, f()) |
| } |
| return ret |
| } |
| |
| // InterceptorInvoker mocks cluster interceptor as an invoker |
| type InterceptorInvoker struct { |
| next protocol.Invoker |
| interceptor Interceptor |
| } |
| |
| // GetURL is used to get url from InterceptorInvoker |
| func (i *InterceptorInvoker) GetURL() *common.URL { |
| return i.next.GetURL() |
| } |
| |
| // IsAvailable is used to get available status |
| func (i *InterceptorInvoker) IsAvailable() bool { |
| return i.next.IsAvailable() |
| } |
| |
| // Invoke is used to call service method by invocation |
| func (i *InterceptorInvoker) Invoke(ctx context.Context, invocation protocol.Invocation) protocol.Result { |
| return i.interceptor.Invoke(ctx, i.next, invocation) |
| } |
| |
| // Destroy will destroy invoker |
| func (i *InterceptorInvoker) Destroy() { |
| i.next.Destroy() |
| } |
| |
| func BuildInterceptorChain(invoker protocol.Invoker, builtins ...Interceptor) protocol.Invoker { |
| // The order of interceptors is from left to right, so loading from right to left |
| next := invoker |
| interceptors := GetClusterInterceptors() |
| if len(interceptors) != 0 { |
| for i := len(interceptors) - 1; i >= 0; i-- { |
| v := &InterceptorInvoker{next: next, interceptor: interceptors[i]} |
| next = v |
| } |
| } |
| |
| if builtins != nil && len(builtins) > 0 { |
| for i := len(builtins) - 1; i >= 0; i-- { |
| v := &InterceptorInvoker{next: next, interceptor: builtins[i]} |
| next = v |
| } |
| } |
| |
| return next |
| } |