mirror of https://github.com/grpc/grpc-go.git
118 lines
2.9 KiB
Go
118 lines
2.9 KiB
Go
/*
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*
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* Copyright 2018 gRPC authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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*/
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// Binary wait_for_ready is an example for "wait for ready".
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package main
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import (
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"context"
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"fmt"
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"log"
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"net"
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"sync"
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"time"
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"google.golang.org/grpc"
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"google.golang.org/grpc/codes"
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"google.golang.org/grpc/credentials/insecure"
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"google.golang.org/grpc/status"
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pb "google.golang.org/grpc/examples/features/proto/echo"
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)
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// server is used to implement EchoServer.
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type server struct {
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pb.UnimplementedEchoServer
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}
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func (s *server) UnaryEcho(_ context.Context, req *pb.EchoRequest) (*pb.EchoResponse, error) {
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return &pb.EchoResponse{Message: req.Message}, nil
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}
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// serve starts listening with a 2 seconds delay.
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func serve() {
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lis, err := net.Listen("tcp", ":50053")
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if err != nil {
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log.Fatalf("failed to listen: %v", err)
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}
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s := grpc.NewServer()
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pb.RegisterEchoServer(s, &server{})
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if err := s.Serve(lis); err != nil {
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log.Fatalf("failed to serve: %v", err)
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}
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}
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func main() {
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conn, err := grpc.NewClient("localhost:50053", grpc.WithTransportCredentials(insecure.NewCredentials()))
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if err != nil {
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log.Fatalf("did not connect: %v", err)
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}
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defer conn.Close()
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c := pb.NewEchoClient(conn)
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var wg sync.WaitGroup
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wg.Add(3)
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// "Wait for ready" is not enabled, returns error with code "Unavailable".
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go func() {
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defer wg.Done()
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ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
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defer cancel()
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_, err := c.UnaryEcho(ctx, &pb.EchoRequest{Message: "Hi!"})
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got := status.Code(err)
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fmt.Printf("[1] wanted = %v, got = %v\n", codes.Unavailable, got)
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}()
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// "Wait for ready" is enabled, returns nil error.
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go func() {
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defer wg.Done()
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ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
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defer cancel()
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_, err := c.UnaryEcho(ctx, &pb.EchoRequest{Message: "Hi!"}, grpc.WaitForReady(true))
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got := status.Code(err)
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fmt.Printf("[2] wanted = %v, got = %v\n", codes.OK, got)
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}()
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// "Wait for ready" is enabled but exceeds the deadline before server starts listening,
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// returns error with code "DeadlineExceeded".
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go func() {
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defer wg.Done()
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ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
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defer cancel()
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_, err := c.UnaryEcho(ctx, &pb.EchoRequest{Message: "Hi!"}, grpc.WaitForReady(true))
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got := status.Code(err)
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fmt.Printf("[3] wanted = %v, got = %v\n", codes.DeadlineExceeded, got)
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}()
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time.Sleep(2 * time.Second)
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go serve()
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wg.Wait()
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}
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