feat: implement client-side streaming file upload example and document it in GRPC.md

examples/grpcentity/server.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"grpccanary/examples/grpcentity/protoapi"
+	"io"
 	"math/rand"
 	"net"
 	"time"
@@ -85,6 +86,32 @@ func (IoTServer) GetRandomPass(ctx context.Context, r *protoapi.RequestPass) (*p
 	return response, nil
 }
 
+func (IoTServer) UploadFile(stream protoapi.IoTService_UploadFileServer) error {
+	var totalBytes int64
+	var fileName string
+
+	for {
+		chunk, err := stream.Recv()
+		if err == io.EOF {
+			fmt.Printf("File upload completed. Received %d bytes for file '%s'\n", totalBytes, fileName)
+			return stream.SendAndClose(&protoapi.UploadStatus{
+				Success:       true,
+				Message:       fmt.Sprintf("File '%s' uploaded successfully.", fileName),
+				BytesUploaded: totalBytes,
+			})
+		}
+		if err != nil {
+			fmt.Println("File upload error:", err)
+			return err
+		}
+
+		if fileName == "" {
+			fileName = chunk.GetFileName()
+		}
+		totalBytes += int64(len(chunk.GetContent()))
+	}
+}
+
 func ServerRun(addr string) {
 	server := grpc.NewServer()
 	var iotServer IoTServer
@@ -92,7 +119,7 @@ func ServerRun(addr string) {
 
 	reflection.Register(server)
 
-	listen, err := net.Listen("tcp", port)
+	listen, err := net.Listen("tcp", addr)
 	if err != nil {
 		fmt.Println(err)
 		return