update to latest micro, optimize flatten

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

json/json.go

@@ -2,8 +2,6 @@
 package json // import "go.unistack.org/micro-codec-segmentio/v3/json"
 
 import (
-	"io"
-
 	"github.com/segmentio/encoding/json"
 	pb "go.unistack.org/micro-proto/v3/codec"
 	"go.unistack.org/micro/v3/codec"
@@ -21,10 +19,9 @@ var (
 	}
 )
 
-var _ codec.Codec = &jsonCodec{}
-
-const (
-	flattenTag = "flatten"
+var (
+	_ codec.Codec   = (*jsonCodec)()
+	_ codec.CodecV2 = (*jsonCodecV2)()
 )
 
 type JsonMarshalOptions struct {
@@ -49,6 +46,12 @@ type jsonCodec struct {
 	decodeFlags json.ParseFlags
 }
 
+type jsonCodecV2 struct {
+	opts        codec.Options
+	encodeFlags json.AppendFlags
+	decodeFlags json.ParseFlags
+}
+
 func getMarshalFlags(o JsonMarshalOptions) json.AppendFlags {
 	var encodeFlags json.AppendFlags
 
@@ -111,8 +114,10 @@ func (c *jsonCodec) Marshal(v interface{}, opts ...codec.Option) ([]byte, error)
 		o(&options)
 	}
 
-	if nv, err := rutil.StructFieldByTag(v, options.TagName, flattenTag); err == nil {
-		v = nv
+	if options.Flatten {
+		if nv, err := rutil.StructFieldByTag(v, options.TagName, "flatten"); err == nil {
+			v = nv
+		}
 	}
 
 	switch m := v.(type) {
@@ -145,8 +150,10 @@ func (c *jsonCodec) Unmarshal(b []byte, v interface{}, opts ...codec.Option) err
 		o(&options)
 	}
 
-	if nv, err := rutil.StructFieldByTag(v, options.TagName, flattenTag); err == nil {
-		v = nv
+	if options.Flatten {
+		if nv, err := rutil.StructFieldByTag(v, options.TagName, "flatten"); err == nil {
+			v = nv
+		}
 	}
 
 	switch m := v.(type) {
@@ -169,41 +176,82 @@ func (c *jsonCodec) Unmarshal(b []byte, v interface{}, opts ...codec.Option) err
 	return err
 }
 
-func (c *jsonCodec) ReadHeader(conn io.Reader, m *codec.Message, t codec.MessageType) error {
-	return nil
+func (c *jsonCodec) String() string {
+	return "json"
 }
 
-func (c *jsonCodec) ReadBody(conn io.Reader, v interface{}) error {
+func (c *jsonCodecV2) Marshal(b []byte, v interface{}, opts ...codec.Option) ([]byte, error) {
 	if v == nil {
-		return nil
+		return nil, nil
 	}
 
-	buf, err := io.ReadAll(conn)
-	if err != nil {
-		return err
-	} else if len(buf) == 0 {
-		return nil
+	options := c.opts
+	for _, o := range opts {
+		o(&options)
 	}
-	return c.Unmarshal(buf, v)
+
+	if options.Flatten {
+		if nv, err := rutil.StructFieldByTag(v, options.TagName, "flatten"); err == nil {
+			v = nv
+		}
+	}
+
+	switch m := v.(type) {
+	case *codec.Frame:
+		return m.Data, nil
+	case *pb.Frame:
+		return m.Data, nil
+	}
+
+	marshalOptions := DefaultMarshalOptions
+	if options.Context != nil {
+		if f, ok := options.Context.Value(marshalOptionsKey{}).(JsonMarshalOptions); ok {
+			marshalOptions = f
+		}
+	}
+
+	var err error
+	b, err = json.Append(b, v, getMarshalFlags(marshalOptions))
+	return b, err
 }
 
-func (c *jsonCodec) Write(conn io.Writer, m *codec.Message, v interface{}) error {
-	if v == nil {
+func (c *jsonCodecV2) Unmarshal(b []byte, v interface{}, opts ...codec.Option) error {
+	if len(b) == 0 || v == nil {
 		return nil
 	}
 
-	buf, err := c.Marshal(v)
-	if err != nil {
-		return err
-	} else if len(buf) == 0 {
-		return codec.ErrInvalidMessage
+	options := c.opts
+	for _, o := range opts {
+		o(&options)
 	}
 
-	_, err = conn.Write(buf)
+	if options.Flatten {
+		if nv, err := rutil.StructFieldByTag(v, options.TagName, "flatten"); err == nil {
+			v = nv
+		}
+	}
+
+	switch m := v.(type) {
+	case *codec.Frame:
+		m.Data = b
+		return nil
+	case *pb.Frame:
+		m.Data = b
+		return nil
+	}
+
+	unmarshalOptions := DefaultUnmarshalOptions
+	if options.Context != nil {
+		if f, ok := options.Context.Value(unmarshalOptionsKey{}).(JsonUnmarshalOptions); ok {
+			unmarshalOptions = f
+		}
+	}
+
+	_, err := json.Parse(b, v, getUnmarshalFlags(unmarshalOptions))
 	return err
 }
 
-func (c *jsonCodec) String() string {
+func (c *jsonCodecV2) String() string {
 	return "json"
 }