server.go

package main

import (
	"context"
	pb "github.com/Example-Collection/go-grpc-server/proto"
	"google.golang.org/grpc"
	"io"
	"log"
	"net"
	"time"
)

type personServiceServer struct {
	// 아래의 UnimplementedPersonServiceServer는 인터페이스 구현을 위해
	// 항상 embed 되어 있어야 한다.
	pb.UnimplementedPersonServiceServer

	// 데이터베이스에 사용자가 저장된 것처럼 PersonRequest들을 담는 배열을 만든다.
	savedPersons []*pb.PersonRequest
}

func personRequestToPersonResponse(req *pb.PersonRequest) *pb.PersonResponse {
	return &pb.PersonResponse{
		Email:   req.Email,
		Age:     req.Age,
		Name:    req.Name,
		Message: "Successfully saved!(name:" + req.Name + ")",
	}
}

func (s *personServiceServer) GetPersonInformation(_ context.Context, req *pb.PersonRequest) (*pb.PersonResponse, error) {
	log.Printf("PersonRequest(name: %v, age: %d, email: %v, password: %v) arrived.\n", req.Name, req.Age, req.Email, req.Password)
	s.savedPersons = append(s.savedPersons, req)
	return personRequestToPersonResponse(req), nil
}

func (s *personServiceServer) ListPersons(req *pb.ListPersonRequest, stream pb.PersonService_ListPersonsServer) error {
	log.Printf("ListPersonRequest(email: %v) arrived.", req.Email)
	for _, person := range s.savedPersons {
		if person.Email == req.Email {
			time.Sleep(time.Second) // Optional
			if err := stream.Send(personRequestToPersonResponse(person)); err != nil {
				return err
			}
		}
	}
	return nil
}

func (s *personServiceServer) SavePersons(stream pb.PersonService_SavePersonsServer) error {
	for {
		req, err := stream.Recv()
		if err == io.EOF {
			log.Println("Read all messages in client stream.\nClosing stream after sending response.")
			return stream.SendAndClose(&pb.BasicResponse{Message: "All requests saved!"})
		}
		if err != nil {
			log.Fatalf("%v.SavePersons(_) = _, %v", s, err)
			return err
		}
		s.savedPersons = append(s.savedPersons, req)
		log.Printf("Saved Person(name: %v, email: %v, age: %d).\n", req.Name, req.Email, req.Age)
	}
	return nil
}

func (s *personServiceServer) AskAndGetPersons(stream pb.PersonService_AskAndGetPersonsServer) error {
	for {
		req, err := stream.Recv()
		if err == io.EOF {
			log.Println("Read all messages from client stream. Closing server stream.")
			return nil
		}
		if err != nil {
			return err
		}
		log.Printf("PersonRequest(email: %v, name: %v, age: %d) arrived.", req.Email, req.Name, req.Age)
		s.savedPersons = append(s.savedPersons, req)
		time.Sleep(time.Second)
		if err := stream.Send(personRequestToPersonResponse(req)); err != nil {
			return err
		}
	}
}

func newServer() *personServiceServer {
	savedPersons := []*pb.PersonRequest{
		{
			Email:    "robbyra@gmail.com",
			Age:      25,
			Name:     "sangwooAged25",
			Password: "sangwooPassword",
		},
		{
			Email:    "robbyra@gmail.com",
			Age:      26,
			Name:     "sangwooAged26",
			Password: "sangwooPassword",
		},
		{
			Email:    "robbyra@gmail.com",
			Age:      27,
			Name:     "sangwooAged27",
			Password: "sangwooPassword",
		},
		{
			Email:    "notSangwoo@gmail.com",
			Age:      1,
			Name:     "notSangwoo",
			Password: "notSangwooPassword",
		},
	}
	return &personServiceServer{savedPersons: savedPersons}
}

func main() {
	lis, err := net.Listen("tcp", "localhost:8081")
	if err != nil {
		log.Fatal("Failed to listen on port 8081")
	}
	var opts []grpc.ServerOption
	grpcServer := grpc.NewServer(opts...)
	pb.RegisterPersonServiceServer(grpcServer, newServer())
	_ = grpcServer.Serve(lis)
}