RPC简介和grpc的使用

import "myproject/other_protos.proto";		// 导入其他 proto文件
syntax = "proto3"; // 指定proto版本
package hello;     // 指定默认包名

// 指定golang包名
option go_package = "hello";

message SearchRequest 
{
  required string query = 1;				// 必须赋值字段
  optional int32 page_number = 2 [default = 10];		// 可选字段
  repeated int32 result_per_page = 3;	// 可重复字段 
}

message SearchResponse 
{
  message Result 		// 嵌套定义
  {
    required string url = 1;
    optional string title = 2;
    repeated string snippets = 3;
  }
  repeated Result result = 1;
}

message SomeOtherMessage 
{
  optional SearchResponse.Result result = 1;	// 使用其他消息的定义
}

service List{				// 定义gRPC服务接口
	rpc getList(SearchRequest) returns (SearchResponse);
}

// 插件自动生成gRPC骨架和存根
protoc --go_out=plugins=grpc: ./ *.proto

syntax = "proto3";
package hello;
// 第一个分割参数，输出路径；第二个设置生成类的包路径

option go_package = "./proto/hello";

// 设置服务名称
service Greeter {
  // 设置方法
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

// 请求信息用户名.
message HelloRequest {
  string name = 1;
}

// 响应信息
message HelloReply {
  string message = 1;
}

package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"net"

	"google.golang.org/grpc"
	pb "mygrpc/proto/hello"
)

var (
	port = flag.Int("port", 50051, "The server port")
)

type server struct {
	pb.UnimplementedGreeterServer
}

func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
	log.Printf("Received: %v", in.GetName())
	return &pb.HelloReply{Message: "Hello " + in.GetName()}, nil
}

func main() {
	flag.Parse()
	lis, err := net.Listen("tcp", fmt.Sprintf(":%d", *port))
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}
	// 开启rpc
	s := grpc.NewServer()
	// 注册服务
	pb.RegisterGreeterServer(s, &server{})
	log.Printf("server listening at %v", lis.Addr())
	if err := s.Serve(lis); err != nil {
		log.Fatalf("failed to serve: %v", err)
	}
}

package main

import (
	"context"
	"flag"
	"log"
	"time"

	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
	pb "mygrpc/proto/hello" // 引入编译生成的包
)

const (
	defaultName = "world"
)

var (
	addr = flag.String("addr", "localhost:50051", "the address to connect to")
	name = flag.String("name", defaultName, "Name to greet")
)

func main() {
	flag.Parse()
	// 与服务建立连接.
	conn, err := grpc.Dial(*addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		log.Fatalf("did not connect: %v", err)
	}
	defer conn.Close()
	// 创建指定服务的客户端
	c := pb.NewGreeterClient(conn)

	// 连接服务器并打印出其响应。
	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	// 调用指定方法
	r, err := c.SayHello(ctx, &pb.HelloRequest{Name: *name})
	if err != nil {
		log.Fatalf("could not greet: %v", err)
	}
	log.Printf("Greeting: %s", r.GetMessage())
}