feat: support for gRPC stream APIs

go.mod

@@ -4,7 +4,6 @@ go 1.11
 
 require (
 	github.com/golang/protobuf v1.5.0
-	golang.org/x/net v0.0.0-20190311183353-d8887717615a
 	google.golang.org/grpc v1.32.0
-	google.golang.org/protobuf v1.27.1
+	google.golang.org/protobuf v1.27.1 // indirect
 )

go.sum

@@ -8,16 +8,15 @@ github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1m
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
-github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.3/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
 github.com/golang/protobuf v1.5.0 h1:LUVKkCeviFUMKqHa4tXIIij/lbhnMbP7Fn5wKdKkRh4=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/nic-chen/grpc_server_example v0.0.0-20190811083654-8dcb31121ca8 h1:niL8VDYTDycXeBTWoXmrzIlDHrTSXdgp4SA0vLoQGj8=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
@@ -42,16 +41,14 @@ golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGm
 golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20190524140312-2c0ae7006135/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
-google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8 h1:Nw54tB0rB7hY/N0NQvRW8DG4Yk3Q6T9cu9RcFQDu1tc=
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55 h1:gSJIx1SDwno+2ElGhA4+qG2zF97qiUzTM+rQ0klBOcE=
 google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55/go.mod h1:DMBHOl98Agz4BDEuKkezgsaosCRResVns1a3J2ZsMNc=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
-google.golang.org/grpc v1.22.1 h1:/7cs52RnTJmD43s3uxzlq2U7nqVTd/37viQwMrMNlOM=
-google.golang.org/grpc v1.22.1/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
 google.golang.org/grpc v1.23.0/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
 google.golang.org/grpc v1.25.1/go.mod h1:c3i+UQWmh7LiEpx4sFZnkU36qjEYZ0imhYfXVyQciAY=
 google.golang.org/grpc v1.32.0 h1:zWTV+LMdc3kaiJMSTOFz2UgSBgx8RNQoTGiZu3fR9S0=

main.go

@@ -27,6 +27,7 @@ import (
 	"crypto/x509"
 	"flag"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"log"
 	"net"
@@ -115,6 +116,59 @@ func (s *server) Plus(ctx context.Context, in *pb.PlusRequest) (*pb.PlusReply, e
 	return &pb.PlusReply{Result: in.A + in.B}, nil
 }
 
+// SayHelloServerStream streams HelloReply back to the client.
+func (s *server) SayHelloServerStream(req *pb.HelloRequest, stream pb.Greeter_SayHelloServerStreamServer) error {
+	log.Printf("Received server side stream req: %v\n", req)
+
+	// Say Hello 5 times.
+	for i := 0; i < 5; i++ {
+		if err := stream.Send(&pb.HelloReply{
+			Message: fmt.Sprintf("Hello %s", req.Name),
+		}); err != nil {
+			return status.Errorf(codes.Unavailable, "Unable to stream request back to client: %v", err)
+		}
+	}
+	return nil
+}
+
+// SayHelloClientStream receives a stream of HelloRequest from a client.
+func (s *server) SayHelloClientStream(stream pb.Greeter_SayHelloClientStreamServer) error {
+	log.Println("SayHello client side streaming has been initiated.")
+	cache := ""
+	for {
+		req, err := stream.Recv()
+		if err == io.EOF {
+			return stream.SendAndClose(&pb.HelloReply{Message: cache})
+		}
+		if err != nil {
+			return status.Errorf(codes.Unavailable, "Failed to read client stream: %v", err)
+		}
+		cache = fmt.Sprintf("%sHello %s!", cache, req.Name)
+	}
+}
+
+// SayHelloBidirectionalStream establishes a bidirectional stream with the client.
+func (s *server) SayHelloBidirectionalStream(stream pb.Greeter_SayHelloBidirectionalStreamServer) error {
+	log.Println("SayHello bidirectional streaming has been initiated.")
+
+	for {
+		req, err := stream.Recv()
+		if err == io.EOF {
+			return stream.Send(&pb.HelloReply{Message: "stream ended"})
+		}
+		if err != nil {
+			return status.Errorf(codes.Unavailable, "Failed to read client stream: %v", err)
+		}
+
+		// A small 0.5 sec sleep
+		time.Sleep(500 * time.Millisecond)
+
+		if err := stream.Send(&pb.HelloReply{Message: fmt.Sprintf("Hello %s", req.Name)}); err != nil {
+			return status.Errorf(codes.Unknown, "Failed to stream response back to client: %v", err)
+		}
+	}
+}
+
 func main() {
 	flag.Parse()
 
@@ -182,7 +236,7 @@ func main() {
 		}()
 	}
 
-	signals := make(chan os.Signal, 1)
+	signals := make(chan os.Signal)
 	signal.Notify(signals, os.Interrupt, syscall.SIGTERM)
 	sig := <-signals
 	log.Printf("get signal %s, exit\n", sig.String())