all: add NewField, NewElement, NewValue
Add methods to protoreflect.{Message,List,Map} to constrict values
assignable to a message field, list element, or map value. These
methods return the default value for scalar fields, the zero value for
scalar list elements and map values, and an empty, mutable value for
messages, lists, and maps.
Deprecate the NewMessage methods on these types, which are superseded.
Updates golang/protobuf#879
Change-Id: I0f064f60c89a239330ccea81523f559f14fd2c4f
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/188997
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/internal/impl/convert.go b/internal/impl/convert.go
index 9016fa4..86da513 100644
--- a/internal/impl/convert.go
+++ b/internal/impl/convert.go
@@ -57,48 +57,67 @@
byteType = reflect.TypeOf(byte(0))
)
+var (
+ boolZero = pref.ValueOf(bool(false))
+ int32Zero = pref.ValueOf(int32(0))
+ int64Zero = pref.ValueOf(int64(0))
+ uint32Zero = pref.ValueOf(uint32(0))
+ uint64Zero = pref.ValueOf(uint64(0))
+ float32Zero = pref.ValueOf(float32(0))
+ float64Zero = pref.ValueOf(float64(0))
+ stringZero = pref.ValueOf(string(""))
+ bytesZero = pref.ValueOf([]byte(nil))
+)
+
type scalarConverter struct {
goType, pbType reflect.Type
def pref.Value
}
func newSingularConverter(t reflect.Type, fd pref.FieldDescriptor) Converter {
+ defVal := func(fd pref.FieldDescriptor, zero pref.Value) pref.Value {
+ if fd.Cardinality() == pref.Repeated {
+ // Default isn't defined for repeated fields.
+ return zero
+ }
+ return fd.Default()
+ }
switch fd.Kind() {
case pref.BoolKind:
if t.Kind() == reflect.Bool {
- return &scalarConverter{t, boolType, fd.Default()}
+ return &scalarConverter{t, boolType, defVal(fd, boolZero)}
}
case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind:
if t.Kind() == reflect.Int32 {
- return &scalarConverter{t, int32Type, fd.Default()}
+ return &scalarConverter{t, int32Type, defVal(fd, int32Zero)}
}
case pref.Int64Kind, pref.Sint64Kind, pref.Sfixed64Kind:
if t.Kind() == reflect.Int64 {
- return &scalarConverter{t, int64Type, fd.Default()}
+ return &scalarConverter{t, int64Type, defVal(fd, int64Zero)}
}
case pref.Uint32Kind, pref.Fixed32Kind:
if t.Kind() == reflect.Uint32 {
- return &scalarConverter{t, uint32Type, fd.Default()}
+ return &scalarConverter{t, uint32Type, defVal(fd, uint32Zero)}
}
case pref.Uint64Kind, pref.Fixed64Kind:
if t.Kind() == reflect.Uint64 {
- return &scalarConverter{t, uint64Type, fd.Default()}
+ return &scalarConverter{t, uint64Type, defVal(fd, uint64Zero)}
}
case pref.FloatKind:
if t.Kind() == reflect.Float32 {
- return &scalarConverter{t, float32Type, fd.Default()}
+ return &scalarConverter{t, float32Type, defVal(fd, float32Zero)}
}
case pref.DoubleKind:
if t.Kind() == reflect.Float64 {
- return &scalarConverter{t, float64Type, fd.Default()}
+ return &scalarConverter{t, float64Type, defVal(fd, float64Zero)}
}
case pref.StringKind:
if t.Kind() == reflect.String || (t.Kind() == reflect.Slice && t.Elem() == byteType) {
- return &scalarConverter{t, stringType, fd.Default()}
+ return &scalarConverter{t, stringType, defVal(fd, stringZero)}
}
case pref.BytesKind:
if t.Kind() == reflect.String || (t.Kind() == reflect.Slice && t.Elem() == byteType) {
- return &scalarConverter{t, bytesType, fd.Default()}
+ return &scalarConverter{t, bytesType, defVal(fd, bytesZero)}
}
case pref.EnumKind:
// Handle enums, which must be a named int32 type.
@@ -133,6 +152,9 @@
}
func (c *scalarConverter) New() pref.Value {
+ if c.pbType == bytesType {
+ return pref.ValueOf(append(([]byte)(nil), c.def.Bytes()...))
+ }
return c.def
}
@@ -142,7 +164,13 @@
}
func newEnumConverter(goType reflect.Type, fd pref.FieldDescriptor) Converter {
- return &enumConverter{goType, fd.Default()}
+ var def pref.Value
+ if fd.Cardinality() == pref.Repeated {
+ def = pref.ValueOf(fd.Enum().Values().Get(0).Number())
+ } else {
+ def = fd.Default()
+ }
+ return &enumConverter{goType, def}
}
func (c *enumConverter) PBValueOf(v reflect.Value) pref.Value {
diff --git a/internal/impl/convert_list.go b/internal/impl/convert_list.go
index a3ef76b..26d3e4c 100644
--- a/internal/impl/convert_list.go
+++ b/internal/impl/convert_list.go
@@ -62,7 +62,10 @@
ls.v.Elem().Set(ls.v.Elem().Slice(0, i))
}
func (ls *listReflect) NewMessage() pref.Message {
- return ls.conv.New().Message()
+ return ls.NewElement().Message()
+}
+func (ls *listReflect) NewElement() pref.Value {
+ return ls.conv.New()
}
func (ls *listReflect) ProtoUnwrap() interface{} {
return ls.v.Interface()
diff --git a/internal/impl/convert_map.go b/internal/impl/convert_map.go
index 69a93d7..185d408 100644
--- a/internal/impl/convert_map.go
+++ b/internal/impl/convert_map.go
@@ -85,7 +85,10 @@
}
}
func (ms *mapReflect) NewMessage() pref.Message {
- return ms.valConv.New().Message()
+ return ms.NewValue().Message()
+}
+func (ms *mapReflect) NewValue() pref.Value {
+ return ms.valConv.New()
}
func (ms *mapReflect) ProtoUnwrap() interface{} {
return ms.v.Interface()
diff --git a/internal/impl/message_field.go b/internal/impl/message_field.go
index e15b861..3dfac23 100644
--- a/internal/impl/message_field.go
+++ b/internal/impl/message_field.go
@@ -26,6 +26,7 @@
set func(pointer, pref.Value)
mutable func(pointer) pref.Value
newMessage func() pref.Message
+ newField func() pref.Value
}
func fieldInfoForOneof(fd pref.FieldDescriptor, fs reflect.StructField, x exporter, ot reflect.Type) fieldInfo {
@@ -113,6 +114,9 @@
newMessage: func() pref.Message {
return conv.New().Message()
},
+ newField: func() pref.Value {
+ return conv.New()
+ },
}
}
@@ -160,6 +164,9 @@
}
return conv.PBValueOf(v)
},
+ newField: func() pref.Value {
+ return conv.New()
+ },
}
}
@@ -204,6 +211,9 @@
v := p.Apply(fieldOffset).AsValueOf(fs.Type)
return conv.PBValueOf(v)
},
+ newField: func() pref.Value {
+ return conv.New()
+ },
}
}
@@ -289,6 +299,9 @@
}
}
},
+ newField: func() pref.Value {
+ return conv.New()
+ },
}
}
@@ -367,6 +380,10 @@
lazyInit()
return messageType.New()
},
+ newField: func() pref.Value {
+ lazyInit()
+ return pref.ValueOf(messageType.New())
+ },
}
}
@@ -417,6 +434,9 @@
newMessage: func() pref.Message {
return conv.New().Message()
},
+ newField: func() pref.Value {
+ return conv.New()
+ },
}
}
diff --git a/internal/impl/message_reflect_gen.go b/internal/impl/message_reflect_gen.go
index e2f6d17..a1c09b4 100644
--- a/internal/impl/message_reflect_gen.go
+++ b/internal/impl/message_reflect_gen.go
@@ -92,11 +92,14 @@
}
}
func (m *messageState) NewMessage(fd protoreflect.FieldDescriptor) protoreflect.Message {
+ return m.NewField(fd).Message()
+}
+func (m *messageState) NewField(fd protoreflect.FieldDescriptor) protoreflect.Value {
m.messageInfo().init()
if fi, xt := m.messageInfo().checkField(fd); fi != nil {
- return fi.newMessage()
+ return fi.newField()
} else {
- return xt.New().Message()
+ return xt.New()
}
}
func (m *messageState) WhichOneof(od protoreflect.OneofDescriptor) protoreflect.FieldDescriptor {
@@ -199,11 +202,14 @@
}
}
func (m *messageReflectWrapper) NewMessage(fd protoreflect.FieldDescriptor) protoreflect.Message {
+ return m.NewField(fd).Message()
+}
+func (m *messageReflectWrapper) NewField(fd protoreflect.FieldDescriptor) protoreflect.Value {
m.messageInfo().init()
if fi, xt := m.messageInfo().checkField(fd); fi != nil {
- return fi.newMessage()
+ return fi.newField()
} else {
- return xt.New().Message()
+ return xt.New()
}
}
func (m *messageReflectWrapper) WhichOneof(od protoreflect.OneofDescriptor) protoreflect.FieldDescriptor {