RPC介紹

Remote Procedure Call，遠程過程調用

解決問題

而一旦踏入公司尤其是大型互聯網公司就會發現，公司的系統都由成千上萬大大小小的服務組成，各服務部署在不同的機器上，由不同的團隊負責。這時就會遇到兩個問題：
1）要搭建一個新服務，免不了需要依賴他人的服務，而現在他人的服務都在遠端，怎么調用？
2）其它團隊要使用我們的服務，我們的服務該怎么發布以便他人調用？

過程

服務消費方（client）調用以本地調用方式調用服務；

client stub接收到調用后負責將方法、參數等組裝成能夠進行網絡傳輸的消息體；

client stub找到服務地址，并將消息發送到服務端；

server stub收到消息后進行解碼；

server stub根據解碼結果調用本地的服務；

本地服務執行并將結果返回給server stub；

server stub將返回結果打包成消息并發送至消費方；

client stub接收到消息，并進行解碼；

服務消費方得到最終結果。

RPC的目標就是要2~8這些步驟都封裝起來，讓用戶對這些細節透明。

實現方式

RPC可以通過HTTP來實現（grpc基于http2.0）,也可以通過Socket自己實現一套協議來實現.

grpc框架

4種通信方式

• 簡單rpc：一個請求對象對應一個返回對象

rpc simpleHello(Person) returns (Result) {}

• 服務端流式rpc ：一個請求對象，服務端可以傳回多個結果對象

rpc serverStreamHello(Person) returns (stream Result) {}

• 客戶端流式rpc：客戶端傳入多個請求對象，服務端返回一個響應結果

rpc clientStreamHello(stream Person) returns (Result) {}

• 雙向流式rpc：可以傳入多個對象，返回多個響應對象

rpc biStreamHello(stream Person) returns (stream Result) {}

案例

simple.proto

syntax = "proto3"; package testRPC;service testRPC {rpc simple (emit) returns (on) {}rpc serverStream (emit) returns (stream on){}rpc clientStream (stream emit) returns (on){}rpc bothStream (stream emit) returns (stream on){} }message emit{string type = 1;string name = 2; }message on{string type = 1;int32 age = 2; }

service

package mainimport ("net""google.golang.org/grpc"pb "google.golang.org/grpc/examples/test/proto""google.golang.org/grpc/reflection""fmt""golang.org/x/net/context""io" )const (port = ":50051" )type server struct { }func (s *server) Simple(ctx context.Context, in *pb.Emit) (*pb.On, error) {return &pb.On{Type: "Hello " + in.Type, Age: 10}, nil } func (s *server) ServerStream(in *pb.Emit, stream pb.TestRPC_ServerStreamServer) (error) {for i := 1; i < 10; i++ {if err := stream.Send(&pb.On{Type: "Hello " + in.Type, Age: int32(i)}); err != nil {return err}}return nil } func (s *server) ClientStream(stream pb.TestRPC_ClientStreamServer) (error) {var pointCount int32for {_, err := stream.Recv()if err == io.EOF {return stream.SendAndClose(&pb.On{Type: "end",Age: pointCount,})}pointCount++} }func (s *server) BothStream(stream pb.TestRPC_BothStreamServer) (error) {for {emit, err := stream.Recv()if err == io.EOF {return nil}fmt.Println(string(emit.Type))for i := 1; i < 3; i++ {if err := stream.Send(&pb.On{Type: emit.Type, Age: int32(i)}); err != nil {return err}}}return nil }func main() {lis, _ := net.Listen("tcp", port)s := grpc.NewServer()pb.RegisterTestRPCServer(s, &server{})reflection.Register(s)if err := s.Serve(lis); err != nil {fmt.Println("error")} }

client

package mainimport ("google.golang.org/grpc"pb "google.golang.org/grpc/examples/test/proto""golang.org/x/net/context""time""log""io" )const (address = "localhost:50051" )func main() {conn, _ := grpc.Dial(address, grpc.WithInsecure())defer conn.Close()rpcClient := pb.NewTestRPCClient(conn)testSimple(rpcClient)testServerStream(rpcClient)testClientStream(rpcClient)testBothStream(rpcClient)}func testSimple(client pb.TestRPCClient) {ctx, cancel := context.WithTimeout(context.Background(), time.Second)defer cancel()// simpler, _ := client.Simple(ctx, &pb.Emit{Type: "11"})log.Printf("Greeting: %s", r) }func testServerStream(client pb.TestRPCClient) {ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)defer cancel()stream, err := client.ServerStream(ctx, &pb.Emit{Type: "Hello "})if err != nil {log.Fatalf("%v.ListFeatures(_) = _, %v", client, err)}for {feature, err := stream.Recv()if err == io.EOF {break}if err != nil {log.Fatalf("%v.ListFeatures(_) = _, %v", client, err)}log.Println(feature)} }func testClientStream(client pb.TestRPCClient) {ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)defer cancel()stream, err := client.ClientStream(ctx)if err != nil {log.Fatalf("%v.RecordRoute(_) = _, %v", client, err)}var points []pb.Emitfor i := 0; i < 10; i++ {points = append(points, pb.Emit{Type: "t", Name: string(i)})}for _, point := range points {if err := stream.Send(&point); err != nil {log.Fatalf("%v.Send(%v) = %v", stream, point, err)}}reply, err := stream.CloseAndRecv()if err != nil {log.Fatalf("%v.CloseAndRecv() got error %v, want %v", stream, err, nil)}log.Printf("Route summary: %v", reply) }func testBothStream(client pb.TestRPCClient) {ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)defer cancel()stream, err := client.BothStream(ctx)if err != nil {log.Fatalf("%v.RecordRoute(_) = _, %v", client, err)}var points []pb.Emitfor i := 0; i < 10; i++ {points = append(points, pb.Emit{Type: "xiaoming"+string(i), Name: "xiaohong"})}waitc := make(chan struct{})go func() {for {on, err := stream.Recv()if err == io.EOF {// read done.close(waitc)return}if err != nil {log.Fatalf("Failed to receive a note : %v", err)}log.Printf("Got message %s = %d)", on.Type, on.Age)}}()for _, point := range points {if err := stream.Send(&point); err != nil {log.Fatalf("Failed to send a note: %v", err)}}stream.CloseSend()<-waitc }

總結

以上是生活随笔為你收集整理的【go网络编程】-RPC编程的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。