| /* |
| * |
| * Copyright 2018 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 main |
| |
| import ( |
| "context" |
| "fmt" |
| "log" |
| "net" |
| "sync" |
| |
| epb "google.golang.org/genproto/googleapis/rpc/errdetails" |
| "google.golang.org/grpc" |
| "google.golang.org/grpc/codes" |
| pb "google.golang.org/grpc/examples/helloworld/helloworld" |
| "google.golang.org/grpc/status" |
| ) |
| |
| const ( |
| port = ":50051" |
| ) |
| |
| // server is used to implement helloworld.GreeterServer. |
| type server struct { |
| mu sync.Mutex |
| count map[string]int |
| } |
| |
| // SayHello implements helloworld.GreeterServer |
| func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) { |
| s.mu.Lock() |
| defer s.mu.Unlock() |
| // Track the number of times the user has been greeted. |
| s.count[in.Name]++ |
| if s.count[in.Name] > 1 { |
| st := status.New(codes.ResourceExhausted, "Request limit exceeded.") |
| ds, err := st.WithDetails( |
| &epb.QuotaFailure{ |
| Violations: []*epb.QuotaFailure_Violation{{ |
| Subject: fmt.Sprintf("name:%s", in.Name), |
| Description: "Limit one greeting per person", |
| }}, |
| }, |
| ) |
| if err != nil { |
| return nil, st.Err() |
| } |
| return nil, ds.Err() |
| } |
| return &pb.HelloReply{Message: "Hello " + in.Name}, nil |
| } |
| |
| func main() { |
| log.Printf("server starting on port %s...", port) |
| lis, err := net.Listen("tcp", port) |
| if err != nil { |
| log.Fatalf("failed to listen: %v", err) |
| } |
| s := grpc.NewServer() |
| pb.RegisterGreeterServer(s, &server{count: make(map[string]int)}) |
| if err := s.Serve(lis); err != nil { |
| log.Fatalf("failed to serve: %v", err) |
| } |
| } |