micro-codec-proto/proto.go

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// Package proto provides a proto codec
package proto // import "go.unistack.org/micro-codec-proto/v3"
import (
"io"
"go.unistack.org/micro/v3/codec"
rutil "go.unistack.org/micro/v3/util/reflect"
"google.golang.org/protobuf/proto"
)
type protoCodec struct {
opts codec.Options
}
var _ codec.Codec = &protoCodec{}
const (
flattenTag = "flatten"
)
func (c *protoCodec) Marshal(v interface{}, opts ...codec.Option) ([]byte, error) {
if v == nil {
return nil, nil
}
options := c.opts
for _, o := range opts {
o(&options)
}
if nv, nerr := rutil.StructFieldByTag(v, options.TagName, flattenTag); nerr == nil {
v = nv
}
if m, ok := v.(*codec.Frame); ok {
return m.Data, nil
}
if _, ok := v.(proto.Message); !ok {
return nil, codec.ErrInvalidMessage
}
return proto.Marshal(v.(proto.Message))
}
func (c *protoCodec) Unmarshal(d []byte, v interface{}, opts ...codec.Option) error {
if v == nil || len(d) == 0 {
return nil
}
options := c.opts
for _, o := range opts {
o(&options)
}
if nv, nerr := rutil.StructFieldByTag(v, options.TagName, flattenTag); nerr == nil {
v = nv
}
if m, ok := v.(*codec.Frame); ok {
m.Data = d
return nil
}
if _, ok := v.(proto.Message); !ok {
return codec.ErrInvalidMessage
}
return proto.Unmarshal(d, v.(proto.Message))
}
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(opts ...codec.Option) codec.Codec {
return &protoCodec{opts: codec.NewOptions(opts...)}
}