add modTime & refresh if file changed

Signed-off-by: Hadi <112569860+anotherhadi@users.noreply.github.com>

back/server/utils.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 )
 
 func getParquetColumns(s Server, path string) []string {
@@ -82,6 +83,14 @@ func getFileSize(path string) uint64 {
 	return uint64(info.Size() / (1024 * 1024)) // MB
 }
 
+func getModTime(path string) time.Time {
+	info, err := os.Stat(path)
+	if err != nil {
+		return time.Time{}
+	}
+	return info.ModTime()
+}
+
 func FormatParquetName(path string) string {
 	_, file := filepath.Split(path)
 	fileName := strings.TrimSuffix(file, ".parquet")