Fix: Handling of exported struct fields

marshal.go

@@ -244,11 +244,22 @@ func encRegister(e interface{}) (err error) {
 		}
 		encoderCache[string(t.Kind())] = f
 	case reflect.Struct:
+		zt := reflect.New(t)
+		n := zt.Elem().NumField()
+		mfields := []int{}
+		for i := 0; i < n; i++ {
+			if zt.Elem().Field(i).CanSet() {
+				mfields = append(mfields, i)
+			}
+		}
+		if len(mfields) == 0 {
+			return errors.New("ssob: No exported fields for " + string(t.Name()))
+		}
+
 		f := func(e interface{}) (ret []byte, err error) {
-			n := v.NumField()
 			bs := make([][]byte, n)
 			blen := 0
-			for i := 0; i < n; i++ {
+			for _, i := range mfields {
 				bs[i], err = marshal(v.Field(i).Interface())
 				if err != nil {
 					return nil, err

unmarshal.go

@@ -269,6 +269,18 @@ func decRegister(e interface{}) (err error) {
 		}
 		decoderCache[string(t.Kind())] = f
 	case reflect.Struct:
+		zt := reflect.New(t)
+		n := zt.Elem().NumField()
+		mfields := []int{}
+		for i := 0; i < n; i++ {
+			if zt.Elem().Field(i).CanSet() {
+				mfields = append(mfields, i)
+			}
+		}
+		if len(mfields) == 0 {
+			return errors.New("ssob: No exported fields for " + string(t.Name()))
+		}
+
 		f := func(e interface{}, in []byte) (n int, err error) {
 			t := reflect.TypeOf(e)
 			v := reflect.ValueOf(e)
@@ -279,8 +291,7 @@ func decRegister(e interface{}) (err error) {
 			}
 
 			vi := reflect.Indirect(v)
-			l := vi.NumField()
-			for i := 0; i < l; i++ {
+			for _, i := range mfields {
 				ni, err := unmarshal(vi.Field(i).Addr().Interface(), in[pos:])
 				pos += ni
 				if err != nil {

unsafe_marshal.go

@@ -354,11 +354,22 @@ func encRegisterUnsafe(e interface{}) (err error) {
 		}
 		unsafeEncoderCache[string(t.Kind())] = f
 	case reflect.Struct:
+		zt := reflect.New(t)
+		n := zt.Elem().NumField()
+		mfields := []int{}
+		for i := 0; i < n; i++ {
+			if zt.Elem().Field(i).CanSet() {
+				mfields = append(mfields, i)
+			}
+		}
+		if len(mfields) == 0 {
+			return errors.New("ssob: No exported fields for " + string(t.Name()))
+		}
+
 		f := func(e interface{}) (ret []byte, err error) {
-			n := v.NumField()
 			bs := make([][]byte, n)
 			blen := 0
-			for i := 0; i < n; i++ {
+			for _, i := range mfields {
 				bs[i], err = unsafeMarshal(v.Field(i).Interface())
 				if err != nil {
 					return nil, err

unsafe_unmarshal.go

@@ -396,6 +396,18 @@ func decRegisterUnsafe(e interface{}) (err error) {
 		}
 		unsafeDecoderCache[string(t.Kind())] = f
 	case reflect.Struct:
+		zt := reflect.New(t)
+		n := zt.Elem().NumField()
+		mfields := []int{}
+		for i := 0; i < n; i++ {
+			if zt.Elem().Field(i).CanSet() {
+				mfields = append(mfields, i)
+			}
+		}
+		if len(mfields) == 0 {
+			return errors.New("ssob: No exported fields for " + string(t.Name()))
+		}
+
 		f := func(e interface{}, in []byte) (n int, err error) {
 			t := reflect.TypeOf(e)
 			v := reflect.ValueOf(e)
@@ -406,8 +418,7 @@ func decRegisterUnsafe(e interface{}) (err error) {
 			}
 
 			vi := reflect.Indirect(v)
-			l := vi.NumField()
-			for i := 0; i < l; i++ {
+			for _, i := range mfields {
 				ni, err := unsafeUnmarshal(vi.Field(i).Addr().Interface(), in[pos:])
 				pos += ni
 				if err != nil {