micro-codec-proto/proto.go

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// Package proto provides a proto codec
package proto
import (
"io"
"github.com/unistack-org/micro/v3/codec"
rutil "github.com/unistack-org/micro/v3/util/reflect"
"google.golang.org/protobuf/proto"
)
type protoCodec struct{}
const (
flattenTag = "flatten"
)
func (c *protoCodec) Marshal(v interface{}) ([]byte, error) {
switch m := v.(type) {
case nil:
return nil, nil
case *codec.Frame:
return m.Data, nil
case proto.Message:
if nv, nerr := rutil.StructFieldByTag(v, codec.DefaultTagName, flattenTag); nerr == nil {
if nm, ok := nv.(proto.Message); ok {
m = nm
}
}
return proto.Marshal(m)
}
return nil, codec.ErrInvalidMessage
}
func (c *protoCodec) Unmarshal(d []byte, v interface{}) error {
if len(d) == 0 {
return nil
}
switch m := v.(type) {
case nil:
return nil
case *codec.Frame:
m.Data = d
case proto.Message:
if nv, nerr := rutil.StructFieldByTag(v, codec.DefaultTagName, flattenTag); nerr == nil {
if nm, ok := nv.(proto.Message); ok {
m = nm
}
}
return proto.Unmarshal(d, m)
}
return codec.ErrInvalidMessage
}
func (c *protoCodec) ReadHeader(conn io.Reader, m *codec.Message, t codec.MessageType) error {
return nil
}
func (c *protoCodec) ReadBody(conn io.Reader, v interface{}) error {
if v == nil {
return nil
}
buf, err := io.ReadAll(conn)
if err != nil {
return err
} else if len(buf) == 0 {
return nil
}
return c.Unmarshal(buf, v)
}
func (c *protoCodec) Write(conn io.Writer, m *codec.Message, v interface{}) error {
if v == nil {
return nil
}
buf, err := c.Marshal(v)
if err != nil {
return err
} else if len(buf) == 0 {
return codec.ErrInvalidMessage
}
_, err = conn.Write(buf)
return err
}
func (c *protoCodec) String() string {
return "proto"
}
func NewCodec() codec.Codec {
return &protoCodec{}
}