added encoder and decoder

msgpack/msgpack.go

@@ -2,6 +2,7 @@ package msgpack
 
 import (
 	"bytes"
+	"io"
 	"sync"
 
 	"github.com/hashicorp/go-msgpack/codec"
@@ -15,31 +16,39 @@ var rdrPool = sync.Pool{
 	New: func() interface{} { return new(bytes.Reader) },
 }
 
-type encoder struct{}
-
-var MsgPack = encoder{}
-
-func (encoder) Unmarshal(b []byte, v interface{}) error {
-	rdr := rdrPool.Get().(*bytes.Reader)
-	rdr.Reset(b)
-	defer rdrPool.Put(rdr)
-	return codec.NewDecoder(rdr, &codec.MsgpackHandle{}).Decode(v)
+func NewEncoder(w io.Writer) *codec.Encoder {
+	return codec.NewEncoder(w, &codec.MsgpackHandle{})
 }
 
-func (encoder) Marshal(v interface{}) ([]byte, error) {
+func NewDecoder(r io.Reader) *codec.Decoder {
+	return codec.NewDecoder(r, &codec.MsgpackHandle{})
+}
+
+type msgPackEncoder struct{}
+
+var MsgPack = msgPackEncoder{}
+
+func (msgPackEncoder) Marshal(v interface{}) ([]byte, error) {
 	buf := bufPool.Get().(*bytes.Buffer)
 	buf.Reset()
-	if err := codec.NewEncoder(buf, &codec.MsgpackHandle{}).Encode(v); err != nil {
+	if err := NewEncoder(buf).Encode(v); err != nil {
 		bufPool.Put(buf)
 		return nil, err
 	}
 	return buf.Bytes(), nil
 }
 
-func Unmarshal(b []byte, v interface{}) error {
-	return MsgPack.Unmarshal(b, v)
+func (msgPackEncoder) Unmarshal(b []byte, v interface{}) error {
+	rdr := rdrPool.Get().(*bytes.Reader)
+	rdr.Reset(b)
+	defer rdrPool.Put(rdr)
+	return NewDecoder(rdr).Decode(v)
 }
 
 func Marshal(v interface{}) ([]byte, error) {
 	return MsgPack.Marshal(v)
 }
+
+func Unmarshal(b []byte, v interface{}) error {
+	return MsgPack.Unmarshal(b, v)
+}