golang——gRPC学习

1、获取gRPC

环境变量GOPATH的src目录下执行：

git clone https://github.com/grpc/grpc-go.git google.golang.org/grpc

git clone https://github.com/golang/net.git golang.org/x/net

git clone https://github.com/golang/text.git golang.org/x/text

go get -u github.com/golang/protobuf/protoc-gen-go

git clone https://github.com/google/go-genproto.git google.golang.org/genproto

go install google.golang.org/grpc

 2、proto文件

gRPC 允许定义4种类型的 service 方法。

（1）编写test.proto

syntax = "proto3";
package test;

//参数
message Question{
    string question_str = 1;
}

//返回
message Answer{
    string answer_str = 1;
}

//定义服务
service Test{
    //简单RPC
    rpc GetAnswer1(Question) returns (Answer){}
    //服务端流式RPC
    rpc GetAnswer2(Question) returns (stream Answer){}
    //客户端流式RPC
    rpc GetAnswer3(stream Question) returns (Answer){}
    //双向流式RPC
    rpc GetAnswer4(stream Question) returns (stream Answer){}
}

（2）生成文件test.pb.go

protoc --go_out=plugins=grpc:. test.proto

3、服务端

package main

import (
	"context"
	"fmt"
	"io"
	"log"
	"net"
	"test/grpc/test"

	"google.golang.org/grpc"
)

type testServer struct{}

//简单RPC
//客户端一次请求，服务端一次响应
func (*testServer) GetAnswer1(ctx context.Context, q *test.Question) (*test.Answer, error) {
	answer := test.Answer{AnswerStr: fmt.Sprintf("Question：%s；Answer：%s。", q.QuestionStr, "Answer1")}
	return &answer, nil
}

//服务端流式RPC
//客户端一次请求，服务端多次响应
func (*testServer) GetAnswer2(q *test.Question, stream test.Test_GetAnswer2Server) error {
	for i := 1; i <= 3; i++ {
		answer := test.Answer{AnswerStr: fmt.Sprintf("Question：%s；Answer：%s%d。", q.QuestionStr, "Answer", i)}
		if err := stream.Send(&answer); err != nil {
			return err
		}
	}
	return nil
}

//客户端流式RPC
//客户端多次请求，服务端一次响应
func (*testServer) GetAnswer3(stream test.Test_GetAnswer3Server) error {
	answer := test.Answer{}
	for i := 1; ; i++ {
		question, err := stream.Recv()
		if err == io.EOF {
			return stream.SendAndClose(&answer)
		}
		if err != nil {
			return err
		}
		answer.AnswerStr = fmt.Sprintf("%sQuestion：%s;Answer：Answer%d。\n", answer.AnswerStr, question.QuestionStr, i)
	}
}

//双向流式RPC
//客户端多次请求，服务端多次响应
func (*testServer) GetAnswer4(stream test.Test_GetAnswer4Server) error {
	for i := 1; ; i++ {
		question, err := stream.Recv()
		if err == io.EOF {
			return nil
		}
		if err != nil {
			return err
		}
		answer := test.Answer{AnswerStr: fmt.Sprintf("Question：%s；Answer：%s%d。", question.QuestionStr, "Answer", i)}
		if err = stream.Send(&answer); err != nil {
			return err
		}
	}

}

func main() {
	lis, err := net.Listen("tcp", "127.0.0.1:5000")
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}
	grpcServer := grpc.NewServer()
	test.RegisterTestServer(grpcServer, &testServer{})
	grpcServer.Serve(lis)
}

4、客户端

package main

import (
	"context"
	"fmt"
	"io"
	"log"
	"test/grpc/test"

	"google.golang.org/grpc"
)

func main() {
	conn, err := grpc.Dial("127.0.0.1:5000", grpc.WithInsecure())
	if err != nil {
		log.Fatalf("fail to dial: %v", err)
	}
	defer conn.Close()
	client := test.NewTestClient(conn)

	fmt.Println("简单RPC===========================")
	question := test.Question{QuestionStr: "问题11111111？"}
	answer, err := client.GetAnswer1(context.Background(), &question)
	if err != nil {
		log.Fatalf("fail to GetAnswer1: %v", err)
	}
	fmt.Println(answer.AnswerStr)

	fmt.Println("服务端流式RPC===========================")
	stream, err := client.GetAnswer2(context.Background(), &question)
	if err != nil {
		log.Fatalf("fail to GetAnswer2: %v", err)
	}
	for {
		answer, err := stream.Recv()
		if err == io.EOF {
			break
		}
		if err != nil {
			log.Fatalf("%v.GetAnswer2, %v", client, err)
		}
		fmt.Println(answer.AnswerStr)
	}

	fmt.Println("客户端流式RPC===========================")
	stream3, err := client.GetAnswer3(context.Background())
	if err != nil {
		log.Fatalf("fail to GetAnswer3: %v", err)
	}
	for i := 1; i <= 3; i++ {
		question := test.Question{QuestionStr: fmt.Sprintf("问题%d", i)}
		if err = stream3.Send(&question); err != nil {
			log.Fatalf("fail to GetAnswer3 Send: %v", err)
		}
	}
	answer, err = stream3.CloseAndRecv()
	if err != nil {
		log.Fatalf("fail to GetAnswer3 CloseAndRecv: %v", err)
	}
	fmt.Println(answer.AnswerStr)

	fmt.Println("双向流式RPC===============================")
	done := make(chan bool)
	stream4, err := client.GetAnswer4(context.Background())
	if err != nil {
		log.Fatalf("fail to GetAnswer4: %v", err)
	}
	//接受服务端响应
	go func() {
		for {
			answer, err := stream4.Recv()
			if err == io.EOF {
				close(done)
				return
			}
			if err != nil {
				log.Fatalf("%v.GetAnswer4, %v", client, err)
			}
			fmt.Println(answer.AnswerStr)
		}
	}()
	//客户端发送请求
	for i := 1; i <= 4; i++ {
		question := test.Question{QuestionStr: fmt.Sprintf("问题%d", i)}
		if err = stream4.Send(&question); err != nil {
			log.Fatalf("fail to GetAnswer3 Send: %v", err)
		}
	}
	stream4.CloseSend()
	<-done
}

5、输出

// 简单RPC===========================
// Question：问题11111111？；Answer：Answer1。
// 服务端流式RPC===========================
// Question：问题11111111？；Answer：Answer1。
// Question：问题11111111？；Answer：Answer2。
// Question：问题11111111？；Answer：Answer3。
// 客户端流式RPC===========================
// Question：问题1;Answer：Answer1。
// Question：问题2;Answer：Answer2。
// Question：问题3;Answer：Answer3。

// 双向流式RPC===============================
// Question：问题1；Answer：Answer1。
// Question：问题2；Answer：Answer2。
// Question：问题3；Answer：Answer3。
// Question：问题4；Answer：Answer4。