feat: implement codec

codec/codec.go

@@ -0,0 +1,34 @@
+package codec
+
+import "io"
+
+type Header struct {
+	ServiceMethod string
+	Seq           uint64
+	Error         string
+}
+
+type Codec interface {
+	io.Closer
+	ReadHeader(*Header) error
+	ReadBody(interface{}) error
+	Write(*Header, interface{}) error
+}
+
+type NewCodecFunc func(closer io.ReadWriteCloser) Codec
+
+type Type string
+
+const (
+	MagicNumber      = 0x12E7165
+	GobType     Type = "application/gob"
+	JsonType    Type = "application/json"
+)
+
+var NewCodecFuncMap map[Type]NewCodecFunc
+
+func init() {
+	NewCodecFuncMap = make(map[Type]NewCodecFunc)
+	NewCodecFuncMap[GobType] = NewGobCodec
+	NewCodecFuncMap[JsonType] = NewJsonCodec
+}

codec/gob.go

@@ -0,0 +1,56 @@
+package codec
+
+import (
+	"bufio"
+	"encoding/gob"
+	"fmt"
+	"io"
+)
+
+type GobCodec struct {
+	conn io.ReadWriteCloser
+	buf  *bufio.Writer
+	dec  *gob.Decoder
+	enc  *gob.Encoder
+}
+
+var _ Codec = (*GobCodec)(nil)
+
+func NewGobCodec(conn io.ReadWriteCloser) Codec {
+	buf := bufio.NewWriter(conn)
+	return &GobCodec{
+		conn: conn,
+		buf:  buf,
+		dec:  gob.NewDecoder(conn),
+		enc:  gob.NewEncoder(buf),
+	}
+}
+
+func (c *GobCodec) ReadHeader(h *Header) error {
+	return c.dec.Decode(h)
+}
+
+func (c *GobCodec) ReadBody(body interface{}) error {
+	return c.dec.Decode(body)
+}
+
+func (c *GobCodec) Write(h *Header, body interface{}) (err error) {
+	defer func() {
+		_ = c.buf.Flush()
+		if err != nil {
+			_ = c.Close()
+		}
+	}()
+
+	if err = c.enc.Encode(h); err != nil {
+		return fmt.Errorf("rpc codec: gob error encoding header: %v", err)
+	}
+	if err = c.enc.Encode(body); err != nil {
+		return fmt.Errorf("rpc codec: gob error encoding body: %v", err)
+	}
+	return nil
+}
+
+func (c *GobCodec) Close() error {
+	return c.conn.Close()
+}

codec/json.go

@@ -0,0 +1,55 @@
+package codec
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"io"
+)
+
+type JsonCodec struct {
+	conn io.ReadWriteCloser
+	buf  *bufio.Writer
+	dec  *json.Decoder
+	enc  *json.Encoder
+}
+
+func (j *JsonCodec) Close() error {
+	return j.conn.Close()
+}
+
+func (j *JsonCodec) ReadHeader(h *Header) error {
+	return j.dec.Decode(h)
+}
+
+func (j *JsonCodec) ReadBody(body interface{}) error {
+	return j.dec.Decode(body)
+}
+
+func (j *JsonCodec) Write(header *Header, body interface{}) (err error) {
+	defer func() {
+		_ = j.buf.Flush()
+		if err != nil {
+			_ = j.Close()
+		}
+	}()
+	if err = j.enc.Encode(header); err != nil {
+		return fmt.Errorf("rpc codec: json error encoding header: %v", err)
+	}
+	if err = j.enc.Encode(body); err != nil {
+		return fmt.Errorf("rpc codec: json error encoding body: %v", err)
+	}
+	return nil
+}
+
+var _ Codec = (*JsonCodec)(nil)
+
+func NewJsonCodec(conn io.ReadWriteCloser) Codec {
+	buf := bufio.NewWriter(conn)
+	return &JsonCodec{
+		conn: conn,
+		buf:  buf,
+		dec:  json.NewDecoder(conn),
+		enc:  json.NewEncoder(buf),
+	}
+}