package common

const (
	OpGet = iota
	OpSet
	OpDel
	OpLst
)

var opNames map[byte]string

func init() {
	opNames = make(map[byte]string, 0)
	opNames[OpGet] = "GET"
	opNames[OpSet] = "SET"
	opNames[OpDel] = "DEL"
	opNames[OpLst] = "LST"
}

type Operation struct {
	OpCode byte
	Key    []byte
	Val    []byte
	WID    int // ID of the handling worker
}

func (op *Operation) Name() string {
	return opNames[op.OpCode]
}

type Request struct {
	Op   *Operation
	Resp chan *Response
}

func (req *Request) OpName() string {
	return req.Op.Name()
}

type Response struct {
	KeyOK  bool
	Body   []byte
	ErrMsg string
}

package common

const (
	OpGet = iota
	OpSet
	OpDel
	OpLst
)

var opNames map[byte]string

func init() {
	opNames = make(map[byte]string, 0)
	opNames[OpGet] = "GET"
	opNames[OpSet] = "SET"
	opNames[OpDel] = "DEL"
	opNames[OpLst] = "LST"
}

type Operation struct {
	OpCode byte
	Key    []byte
	Val    []byte
	WID    int // ID of the handling worker
}

func (op *Operation) Name() string {
	return opNames[op.OpCode]
}

type Request struct {
	Op   *Operation
	Resp chan *Response
}

func (req *Request) OpName() string {
	return req.Op.Name()
}

type Response struct {
	Body []byte
}

--- 
+++ 
@@ -38,5 +38,7 @@
 }
 
 type Response struct {
-	Body []byte
+	KeyOK  bool
+	Body   []byte
+	ErrMsg string
 }
Add field in Response indicating presence of key in store.
