refactor: refactor print GRPC message (#386)

pkg/util/grpc.go

@@ -0,0 +1,83 @@
+package util
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+type Printable interface {
+	GetMessage() string
+}
+
+func PrintGRPCStream[T any](clientStream grpc.ClientStream, writers ...io.Writer) error {
+	var out io.Writer = os.Stdout
+	for _, writer := range writers {
+		out = writer
+		break
+	}
+
+	for {
+		var t = new(T)
+		err := clientStream.RecvMsg(t)
+		if errors.Is(err, io.EOF) {
+			return nil
+		}
+		if status.Code(err) == codes.Canceled {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+		if out == nil {
+			continue
+		}
+		if p, ok := any(t).(Printable); ok {
+			_, _ = fmt.Fprintf(out, p.GetMessage())
+		} else {
+			buf, _ := json.Marshal(t)
+			_, _ = fmt.Fprintf(out, string(buf))
+		}
+	}
+}
+
+func CopyGRPCStream[T any](r grpc.ClientStream, w grpc.ServerStream) error {
+	for {
+		var t = new(T)
+		err := r.RecvMsg(t)
+		if errors.Is(err, io.EOF) {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+		err = w.SendMsg(t)
+		if err != nil {
+			return err
+		}
+	}
+}
+
+func CopyAndConvertGRPCStream[I any, O any](r grpc.ClientStream, w grpc.ServerStream, convert func(*I) *O) error {
+	for {
+		var i = new(I)
+		err := r.RecvMsg(i)
+		if errors.Is(err, io.EOF) {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+		o := convert(i)
+		err = w.SendMsg(o)
+		if err != nil {
+			return err
+		}
+	}
+}