first

internal/grpc/client.go

@@ -0,0 +1,48 @@
+package grpc
+
+import (
+	"context"
+
+	pb "spektr/internal/grpc/pb"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+type Client struct {
+	conn   *grpc.ClientConn
+	cancel context.CancelFunc
+	stream pb.ReceiverService_ConnectClient
+}
+
+func Dial(ctx context.Context, addr string) (*Client, error) {
+	conn, err := grpc.DialContext(ctx, addr, grpc.WithBlock(), grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		return nil, err
+	}
+
+	client := pb.NewReceiverServiceClient(conn)
+	streamCtx, cancel := context.WithCancel(context.Background())
+	stream, err := client.Connect(streamCtx)
+	if err != nil {
+		cancel()
+		_ = conn.Close()
+		return nil, err
+	}
+
+	return &Client{conn: conn, cancel: cancel, stream: stream}, nil
+}
+
+func (c *Client) Send(msg *pb.ClientMessage) (*pb.ServerMessage, error) {
+	if err := c.stream.Send(msg); err != nil {
+		return nil, err
+	}
+	return c.stream.Recv()
+}
+
+func (c *Client) Close() error {
+	if c.cancel != nil {
+		c.cancel()
+	}
+	return c.conn.Close()
+}

internal/grpc/server.go

@@ -0,0 +1,57 @@
+package grpc
+
+import (
+	"context"
+	"log"
+	"net"
+
+	pb "spektr/internal/grpc/pb"
+
+	"google.golang.org/grpc"
+)
+
+type server struct {
+	pb.UnimplementedReceiverServiceServer
+	handler Handler
+}
+
+func (s *server) Connect(stream pb.ReceiverService_ConnectServer) error {
+	log.Println("client connected")
+	for {
+		msg, err := stream.Recv()
+		if err != nil {
+			log.Println("client disconnected:", err)
+			return err
+		}
+
+		log.Printf("recv request_id=%s", msg.GetRequestId())
+		resp := s.handler.Handle(stream.Context(), msg)
+		if resp == nil {
+			continue
+		}
+
+		if err := stream.Send(resp); err != nil {
+			log.Println("send error:", err)
+			return err
+		}
+		log.Printf("sent request_id=%s", resp.GetRequestId())
+	}
+}
+
+func Serve(ctx context.Context, addr string, handler Handler) error {
+	lis, err := net.Listen("tcp", addr)
+	if err != nil {
+		return err
+	}
+
+	srv := grpc.NewServer()
+	pb.RegisterReceiverServiceServer(srv, &server{handler: handler})
+
+	go func() {
+		<-ctx.Done()
+		srv.GracefulStop()
+	}()
+
+	log.Println("gRPC listening on", addr)
+	return srv.Serve(lis)
+}

internal/grpc/stream.go

@@ -0,0 +1,11 @@
+package grpc
+
+import (
+	"context"
+
+	pb "spektr/internal/grpc/pb"
+)
+
+type Handler interface {
+	Handle(context.Context, *pb.ClientMessage) *pb.ServerMessage
+}