1 // 2 // 3 // Copyright 2020 gRPC authors. 4 // 5 // Licensed under the Apache License, Version 2.0 (the "License"); 6 // you may not use this file except in compliance with the License. 7 // You may obtain a copy of the License at 8 // 9 // http://www.apache.org/licenses/LICENSE-2.0 10 // 11 // Unless required by applicable law or agreed to in writing, software 12 // distributed under the License is distributed on an "AS IS" BASIS, 13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 // See the License for the specific language governing permissions and 15 // limitations under the License. 16 // 17 // 18 19 #ifndef GRPCPP_XDS_SERVER_BUILDER_H 20 #define GRPCPP_XDS_SERVER_BUILDER_H 21 22 #include <grpc/impl/codegen/port_platform.h> 23 24 #include <grpcpp/server_builder.h> 25 26 namespace grpc { 27 namespace experimental { 28 29 class XdsServerServingStatusNotifierInterface { 30 public: 31 virtual ~XdsServerServingStatusNotifierInterface() = default; 32 33 // \a uri contains the listening target associated with the notification. Note 34 // that a single target provided to XdsServerBuilder can get resolved to 35 // multiple listening addresses. 36 // The callback is invoked each time there is an update to the serving status. 37 // The API does not provide any guarantees around duplicate updates. 38 // Status::OK signifies that the server is serving, while a non-OK status 39 // signifies that the server is not serving. 40 virtual void OnServingStatusUpdate(std::string uri, grpc::Status status) = 0; 41 }; 42 43 class XdsServerBuilder : public ::grpc::ServerBuilder { 44 public: 45 // It is the responsibility of the application to make sure that \a notifier 46 // outlasts the life of the server. Notifications will start being made 47 // asynchronously once `BuildAndStart()` has been called. Note that it is 48 // possible for notifications to be made before `BuildAndStart()` returns. set_status_notifier(XdsServerServingStatusNotifierInterface * notifier)49 void set_status_notifier(XdsServerServingStatusNotifierInterface* notifier) { 50 notifier_ = notifier; 51 } 52 53 private: 54 // Called at the beginning of BuildAndStart(). BuildChannelArgs()55 ChannelArguments BuildChannelArgs() override { 56 ChannelArguments args = ServerBuilder::BuildChannelArgs(); 57 grpc_channel_args c_channel_args = args.c_channel_args(); 58 grpc_server_config_fetcher* fetcher = grpc_server_config_fetcher_xds_create( 59 {OnServingStatusUpdate, notifier_}, &c_channel_args); 60 if (fetcher != nullptr) set_fetcher(fetcher); 61 return args; 62 } 63 OnServingStatusUpdate(void * user_data,const char * uri,grpc_status_code code,const char * error_message)64 static void OnServingStatusUpdate(void* user_data, const char* uri, 65 grpc_status_code code, 66 const char* error_message) { 67 if (user_data == nullptr) return; 68 XdsServerServingStatusNotifierInterface* notifier = 69 static_cast<XdsServerServingStatusNotifierInterface*>(user_data); 70 notifier->OnServingStatusUpdate( 71 uri, grpc::Status(static_cast<StatusCode>(code), error_message)); 72 } 73 74 XdsServerServingStatusNotifierInterface* notifier_ = nullptr; 75 }; 76 77 } // namespace experimental 78 } // namespace grpc 79 80 #endif /* GRPCPP_XDS_SERVER_BUILDER_H */ 81