Merge pull request #23871 from smarterclayton/proto_timestamp

Implement a simpler unversioned.Time serialization

cmd/libs/go2idl/go-to-protobuf/protobuf/generator.go

@@ -135,8 +135,9 @@ func (g *genProtoIDL) GenerateType(c *generator.Context, t *types.Type, w io.Wri
 	sw := generator.NewSnippetWriter(w, c, "$", "$")
 	b := bodyGen{
 		locator: &protobufLocator{
-			namer:   c.Namers["proto"].(ProtobufFromGoNamer),
-			tracker: g.imports,
+			namer:    c.Namers["proto"].(ProtobufFromGoNamer),
+			tracker:  g.imports,
+			universe: c.Universe,
 
 			localGoPackage: g.localGoPackage.Package,
 		},
@@ -164,12 +165,14 @@ type ProtobufFromGoNamer interface {
 
 type ProtobufLocator interface {
 	ProtoTypeFor(t *types.Type) (*types.Type, error)
+	GoTypeForName(name types.Name) *types.Type
 	CastTypeName(name types.Name) string
 }
 
 type protobufLocator struct {
-	namer   ProtobufFromGoNamer
-	tracker namer.ImportTracker
+	namer    ProtobufFromGoNamer
+	tracker  namer.ImportTracker
+	universe types.Universe
 
 	localGoPackage string
 }
@@ -183,6 +186,13 @@ func (p protobufLocator) CastTypeName(name types.Name) string {
 	return name.String()
 }
 
+func (p protobufLocator) GoTypeForName(name types.Name) *types.Type {
+	if len(name.Package) == 0 {
+		name.Package = p.localGoPackage
+	}
+	return p.universe.Type(name)
+}
+
 // ProtoTypeFor locates a Protobuf type for the provided Go type (if possible).
 func (p protobufLocator) ProtoTypeFor(t *types.Type) (*types.Type, error) {
 	switch {
@@ -231,6 +241,7 @@ func (b bodyGen) doStruct(sw *generator.SnippetWriter) error {
 		return nil
 	}
 
+	var alias *types.Type
 	var fields []protoField
 	options := []string{}
 	allOptions := types.ExtractCommentTags("+", b.t.CommentLines)
@@ -254,6 +265,14 @@ func (b bodyGen) doStruct(sw *generator.SnippetWriter) error {
 					options = append(options, fmt.Sprintf("%s = %s", key, v))
 				}
 			}
+		// protobuf.as allows a type to have the same message contents as another Go type
+		case k == "protobuf.as":
+			fields = nil
+			if alias = b.locator.GoTypeForName(types.Name{Name: v}); alias == nil {
+				return fmt.Errorf("type %v references alias %q which does not exist", b.t, v)
+			}
+		// protobuf.embed instructs the generator to use the named type in this package
+		// as an embedded message.
 		case k == "protobuf.embed":
 			fields = []protoField{
 				{
@@ -270,10 +289,13 @@ func (b bodyGen) doStruct(sw *generator.SnippetWriter) error {
 			}
 		}
 	}
+	if alias == nil {
+		alias = b.t
+	}
 
 	// If we don't explicitly embed anything, generate fields by traversing fields.
 	if fields == nil {
-		memberFields, err := membersToFields(b.locator, b.t, b.localPackage, b.omitFieldTypes)
+		memberFields, err := membersToFields(b.locator, alias, b.localPackage, b.omitFieldTypes)
 		if err != nil {
 			return fmt.Errorf("type %v cannot be converted to protobuf: %v", b.t, err)
 		}
@@ -454,7 +476,7 @@ func memberTypeToProtobufField(locator ProtobufLocator, field *protoField, t *ty
 
 // protobufTagToField extracts information from an existing protobuf tag
 func protobufTagToField(tag string, field *protoField, m types.Member, t *types.Type, localPackage types.Name) error {
-	if len(tag) == 0 {
+	if len(tag) == 0 || tag == "-" {
 		return nil
 	}
 

cmd/libs/go2idl/go-to-protobuf/protobuf/namer.go

@@ -131,7 +131,11 @@ func assignGoTypeToProtoPackage(p *protobufPackage, t *types.Type, local, global
 			continue
 		}
 		field := &protoField{}
-		if err := protobufTagToField(reflect.StructTag(m.Tags).Get("protobuf"), field, m, t, p.ProtoTypeName()); err == nil && field.Type != nil {
+		tag := reflect.StructTag(m.Tags).Get("protobuf")
+		if tag == "-" {
+			continue
+		}
+		if err := protobufTagToField(tag, field, m, t, p.ProtoTypeName()); err == nil && field.Type != nil {
 			assignGoTypeToProtoPackage(p, field.Type, local, global)
 			continue
 		}

pkg/api/unversioned/time.go

@@ -28,8 +28,9 @@ import (
 // of the factory methods that the time package offers.
 //
 // +protobuf.options.marshal=false
+// +protobuf.as=Timestamp
 type Time struct {
-	time.Time `protobuf:"Timestamp,1,req,name=time"`
+	time.Time `protobuf:"-"`
 }
 
 // NewTime returns a wrapped instance of the provided time

pkg/api/unversioned/time_proto.go

@@ -22,15 +22,9 @@ import (
 	"time"
 )
 
-// ProtoTime is a struct that is equivalent to Time, but intended for
+// Timestamp is a struct that is equivalent to Time, but intended for
 // protobuf marshalling/unmarshalling. It is generated into a serialization
 // that matches Time. Do not use in Go structs.
-type ProtoTime struct {
-	// Represents the time of an event.
-	Timestamp Timestamp `json:"timestamp"`
-}
-
-// Timestamp is a protobuf Timestamp compatible representation of time.Time
 type Timestamp struct {
 	// Represents seconds of UTC time since Unix epoch
 	// 1970-01-01T00:00:00Z. Must be from from 0001-01-01T00:00:00Z to
@@ -39,20 +33,18 @@ type Timestamp struct {
 	// Non-negative fractions of a second at nanosecond resolution. Negative
 	// second values with fractions must still have non-negative nanos values
 	// that count forward in time. Must be from 0 to 999,999,999
-	// inclusive.
+	// inclusive. This field may be limited in precision depending on context.
 	Nanos int32 `json:"nanos"`
 }
 
-// ProtoTime returns the Time as a new ProtoTime value.
-func (m *Time) ProtoTime() *ProtoTime {
+// Timestamp returns the Time as a new Timestamp value.
+func (m *Time) ProtoTime() *Timestamp {
 	if m == nil {
-		return &ProtoTime{}
+		return &Timestamp{}
 	}
-	return &ProtoTime{
-		Timestamp: Timestamp{
-			Seconds: m.Time.Unix(),
-			Nanos:   int32(m.Time.Nanosecond()),
-		},
+	return &Timestamp{
+		Seconds: m.Time.Unix(),
+		Nanos:   int32(m.Time.Nanosecond()),
 	}
 }
 
@@ -61,11 +53,11 @@ func (m *Time) Size() (n int) { return m.ProtoTime().Size() }
 
 // Reset implements the protobuf marshalling interface.
 func (m *Time) Unmarshal(data []byte) error {
-	p := ProtoTime{}
+	p := Timestamp{}
 	if err := p.Unmarshal(data); err != nil {
 		return err
 	}
-	m.Time = time.Unix(p.Timestamp.Seconds, int64(p.Timestamp.Nanos))
+	m.Time = time.Unix(p.Seconds, int64(p.Nanos))
 	return nil
 }