X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=codec%2Fmsg_codec.go;h=227764d0eb7760dddf748066a022c6d1517b3d23;hb=8d3131f90f71271835e5fed91831565797894614;hp=7ba87711b2d00c6ac70ddd94747bcaffed92d88b;hpb=a679bbc78b98089f9b221bbe7de963f5274073bb;p=govpp.git

diff --git a/codec/msg_codec.go b/codec/msg_codec.go
index 7ba8771..227764d 100644
--- a/codec/msg_codec.go
+++ b/codec/msg_codec.go
@@ -15,127 +15,116 @@
 package codec
 
 import (
-	"bytes"
+	"encoding/binary"
 	"errors"
 	"fmt"
-	"reflect"
 
 	"git.fd.io/govpp.git/api"
-	"github.com/lunixbochs/struc"
 )
 
-// MsgCodec provides encoding and decoding functionality of `api.Message` structs into/from
-// binary format as accepted by VPP.
-type MsgCodec struct{}
-
-// VppRequestHeader struct contains header fields implemented by all VPP requests.
-type VppRequestHeader struct {
-	VlMsgID     uint16
-	ClientIndex uint32
-	Context     uint32
-}
+var DefaultCodec = new(MsgCodec)
 
-// VppReplyHeader struct contains header fields implemented by all VPP replies.
-type VppReplyHeader struct {
-	VlMsgID uint16
-	Context uint32
+func EncodeMsg(msg api.Message, msgID uint16) (data []byte, err error) {
+	return DefaultCodec.EncodeMsg(msg, msgID)
 }
-
-// VppEventHeader struct contains header fields implemented by all VPP events.
-type VppEventHeader struct {
-	VlMsgID uint16
-	Context uint32
+func DecodeMsg(data []byte, msg api.Message) (err error) {
+	return DefaultCodec.DecodeMsg(data, msg)
 }
-
-// VppOtherHeader struct contains header fields implemented by other VPP messages (not requests nor replies).
-type VppOtherHeader struct {
-	VlMsgID uint16
+func DecodeMsgContext(data []byte, msgType api.MessageType) (context uint32, err error) {
+	return DefaultCodec.DecodeMsgContext(data, msgType)
 }
 
-const (
-	vppRequestHeaderSize = 10 // size of a VPP request header
-	vppReplyHeaderSize   = 6  // size of a VPP reply header
-	vppEventHeaderSize   = 6  // size of a VPP event header
-	vppOtherHeaderSize   = 2  // size of the header of other VPP messages
-)
+// MsgCodec provides encoding and decoding functionality of `api.Message` structs into/from
+// binary format as accepted by VPP.
+type MsgCodec struct{}
 
-// EncodeMsg encodes provided `Message` structure into its binary-encoded data representation.
-func (*MsgCodec) EncodeMsg(msg api.Message, msgID uint16) ([]byte, error) {
+func (*MsgCodec) EncodeMsg(msg api.Message, msgID uint16) (data []byte, err error) {
 	if msg == nil {
 		return nil, errors.New("nil message passed in")
 	}
 
-	buf := new(bytes.Buffer)
-
-	// encode message header
-	var header interface{}
-	if msg.GetMessageType() == api.RequestMessage {
-		header = &VppRequestHeader{VlMsgID: msgID}
-	} else if msg.GetMessageType() == api.ReplyMessage {
-		header = &VppReplyHeader{VlMsgID: msgID}
-	} else if msg.GetMessageType() == api.EventMessage {
-		header = &VppEventHeader{VlMsgID: msgID}
-	} else {
-		header = &VppOtherHeader{VlMsgID: msgID}
-	}
-	err := struc.Pack(buf, header)
-	if err != nil {
-		return nil, fmt.Errorf("unable to encode message: header: %v, error %v", header, err)
+	// try to recover panic which might possibly occur
+	defer func() {
+		if r := recover(); r != nil {
+			var ok bool
+			if err, ok = r.(error); !ok {
+				err = fmt.Errorf("%v", r)
+			}
+			err = fmt.Errorf("panic occurred during encoding message %s: %v", msg.GetMessageName(), err)
+		}
+	}()
+
+	marshaller, ok := msg.(Marshaler)
+	if !ok {
+		marshaller = Wrapper{msg}
 	}
 
-	// encode message content
-	if reflect.Indirect(reflect.ValueOf(msg)).NumField() > 0 {
-		err := struc.Pack(buf, msg)
-		if err != nil {
-			return nil, fmt.Errorf("unable to encode message: header %v, error %v", header, err)
-		}
+	size := marshaller.Size()
+	offset := getOffset(msg)
+
+	// encode msg ID
+	b := make([]byte, size+offset)
+	b[0] = byte(msgID >> 8)
+	b[1] = byte(msgID)
+
+	data, err = marshaller.Marshal(b[offset:])
+	if err != nil {
+		return nil, err
 	}
 
-	return buf.Bytes(), nil
+	return b[0:len(b):len(b)], nil
 }
 
-// DecodeMsg decodes binary-encoded data of a message into provided `Message` structure.
-func (*MsgCodec) DecodeMsg(data []byte, msg api.Message) error {
+func (*MsgCodec) DecodeMsg(data []byte, msg api.Message) (err error) {
 	if msg == nil {
 		return errors.New("nil message passed in")
 	}
 
-	buf := bytes.NewReader(data)
-
-	// check which header is expected
-	var header interface{}
-	if msg.GetMessageType() == api.RequestMessage {
-		header = &VppRequestHeader{}
-	} else if msg.GetMessageType() == api.ReplyMessage {
-		header = &VppReplyHeader{}
-	} else if msg.GetMessageType() == api.EventMessage {
-		header = &VppEventHeader{}
-	} else {
-		header = &VppOtherHeader{}
-	}
+	// try to recover panic which might possibly occur
+	defer func() {
+		if r := recover(); r != nil {
+			var ok bool
+			if err, ok = r.(error); !ok {
+				err = fmt.Errorf("%v", r)
+			}
+			err = fmt.Errorf("panic occurred during decoding message %s: %v", msg.GetMessageName(), err)
+		}
+	}()
 
-	// decode message header
-	err := struc.Unpack(buf, header)
-	if err != nil {
-		return fmt.Errorf("unable to decode message: data %v, error %v", data, err)
+	marshaller, ok := msg.(Unmarshaler)
+	if !ok {
+		marshaller = Wrapper{msg}
 	}
 
-	// get rid of the message header
-	if msg.GetMessageType() == api.RequestMessage {
-		buf = bytes.NewReader(data[vppRequestHeaderSize:])
-	} else if msg.GetMessageType() == api.ReplyMessage {
-		buf = bytes.NewReader(data[vppReplyHeaderSize:])
-	} else if msg.GetMessageType() == api.EventMessage {
-		buf = bytes.NewReader(data[vppEventHeaderSize:])
-	} else {
-		buf = bytes.NewReader(data[vppOtherHeaderSize:])
-	}
+	offset := getOffset(msg)
 
-	// decode message content
-	err = struc.Unpack(buf, msg)
+	err = marshaller.Unmarshal(data[offset:len(data)])
 	if err != nil {
-		return fmt.Errorf("unable to decode message: data %v, error %v", data, err)
+		return err
 	}
 
 	return nil
 }
+
+func (*MsgCodec) DecodeMsgContext(data []byte, msgType api.MessageType) (context uint32, err error) {
+	switch msgType {
+	case api.RequestMessage:
+		return binary.BigEndian.Uint32(data[6:10]), nil
+	case api.ReplyMessage:
+		return binary.BigEndian.Uint32(data[2:6]), nil
+	}
+
+	return 0, nil
+}
+
+func getOffset(msg api.Message) (offset int) {
+	switch msg.GetMessageType() {
+	case api.RequestMessage:
+		return 10
+	case api.ReplyMessage:
+		return 6
+	case api.EventMessage:
+		return 6
+	}
+	return 2
+}