pkg/serializer: do not write field names if it won't save space

If we are going to write all values, don't write field names.
This only increases size of generated files.
The change reduces size of generated files by 5.8%
(62870496-59410354=3460142 bytes saved).

2 files changed, 22 insertions, 7 deletions

diff --git a/pkg/serializer/serializer.go b/pkg/serializer/serializer.go
index 473b6fa74..4de4dc093 100644
--- a/pkg/serializer/serializer.go
+++ b/pkg/serializer/serializer.go
@@ -57,7 +57,10 @@ func (w *writer) do(v reflect.Value, sliceElem bool) {
 	case reflect.String:
 		fmt.Fprintf(w.w, "%q", v.String())
 	case reflect.Func:
-		// Skip, no way to serialize this.
+		if !v.IsNil() {
+			panic("no way to serialize funcs")
+		}
+		fmt.Fprintf(w.w, "nil")
 	default:
 		panic(fmt.Sprintf("unsupported type: %#v", v.Type().String()))
 	}
@@ -111,17 +114,27 @@ func (w *writer) doStruct(v reflect.Value, sliceElem bool) {
 		w.string(v.Type().Name())
 	}
 	w.byte('{')
+	fieldNames := false
+	for i := 0; i < v.NumField(); i++ {
+		f := v.Field(i)
+		if isDefaultValue(f) || !f.CanSet() {
+			fieldNames = true
+			break
+		}
+	}
 	needComma := false
 	for i := 0; i < v.NumField(); i++ {
 		f := v.Field(i)
-		if isDefaultValue(f) {
+		if fieldNames && (isDefaultValue(f) || !f.CanSet()) {
 			continue
 		}
 		if needComma {
 			w.byte(',')
 		}
-		w.string(v.Type().Field(i).Name)
-		w.byte(':')
+		if fieldNames {
+			w.string(v.Type().Field(i).Name)
+			w.byte(':')
+		}
 		w.do(f, false)
 		needComma = true
 	}
@@ -177,7 +190,7 @@ func isDefaultValue(v reflect.Value) bool {
 	case reflect.String:
 		return v.String() == ""
 	case reflect.Func:
-		return true
+		return false
 	default:
 		return false
 	}
diff --git a/pkg/serializer/serializer_test.go b/pkg/serializer/serializer_test.go
index 06dbaf304..c33b316a9 100644
--- a/pkg/serializer/serializer_test.go
+++ b/pkg/serializer/serializer_test.go
@@ -13,9 +13,10 @@ func TestSerializer(t *testing.T) {
 		Y: Y{1},
 		P: &Y{2},
 		A: []Y{{3}, {4}},
-		F: true,
+		B: true,
 		S: "a\x09b",
 		T: T1,
+		F: nil,
 	}
 	buf := new(bytes.Buffer)
 	Write(buf, x)
@@ -27,9 +28,10 @@ type X struct {
 	Y Y
 	P *Y
 	A []Y
-	F bool
+	B bool
 	S string
 	T T
+	F func()
 }
 
 type Y struct {