feat: optimize hash mem copy

command.go

@@ -93,11 +93,15 @@ func pingCommand(writer *resp.Writer, _ []resp.RESP) {
 }
 
 func setCommand(writer *resp.Writer, args []resp.RESP) {
-	key := args[0].ToString()
-	value := args[1].Clone()
+	key := args[0].ToStringUnsafe()
 	extra := args[2:]
 	var ttl int64
 
+	_, ttl = db.dict.Get(key)
+	if ttl == KeyNotExist {
+		key = args[0].ToString() // copy
+	}
+
 	for len(extra) > 0 {
 		arg := extra[0].ToStringUnsafe()
 
@@ -140,6 +144,7 @@ func setCommand(writer *resp.Writer, args []resp.RESP) {
 		}
 	}
 
+	value := args[1].Clone()
 	db.dict.SetWithTTL(key, value, ttl)
 	writer.WriteSString("OK")
 }
@@ -212,7 +217,7 @@ func hsetCommand(writer *resp.Writer, args []resp.RESP) {
 	var count int
 	for i := 0; i < len(args); i += 2 {
 		field := args[i].ToString()
-		value := args[i+1].Clone()
+		value := args[i+1] // no need to clone
 		if hmap.Set(field, value) {
 			count++
 		}

const.go

@@ -23,8 +23,8 @@ const (
 )
 
 const (
-	KeepTTL     = redis.KeepTTL
-	KeyNotExist = -2
+	KeepTTL     int64 = redis.KeepTTL
+	KeyNotExist int64 = -2
 )
 
 const (

dict.go

@@ -18,7 +18,7 @@ func New() *Dict {
 	}
 }
 
-func (dict *Dict) Get(key string) (any, int) {
+func (dict *Dict) Get(key string) (any, int64) {
 	data, ok := dict.data.Get(key)
 	if !ok {
 		// key not exist
@@ -37,7 +37,7 @@ func (dict *Dict) Get(key string) (any, int) {
 		return nil, KeyNotExist
 	}
 
-	return data, int(ts-now) / int(time.Second)
+	return data, (ts - now) / int64(time.Second)
 }
 
 func (dict *Dict) Set(key string, data any) {

dict_test.go

@@ -30,7 +30,7 @@ func TestDict(t *testing.T) {
 		time.Sleep(time.Second / 10)
 
 		data, ttl := dict.Get("key")
-		assert.Equal(ttl, 59)
+		assert.Equal(ttl, int64(59))
 		assert.Equal(data, []byte("hello"))
 
 		res := dict.SetTTL("key", time.Now().Add(-time.Second).UnixNano())