feat: add scan command

command.go

@@ -15,12 +15,14 @@ import (
 	"github.com/xgzlucario/rotom/internal/zset"
 )
 
-var (
-	WithScores = "WITHSCORES"
+const (
 	KeepTtl    = "KEEPTTL"
+	Count      = "COUNT"
+	Match      = "MATCH"
 	NX         = "NX"
 	EX         = "EX"
 	PX         = "PX"
+	WithScores = "WITHSCORES"
 )
 
 type Command struct {
@@ -43,6 +45,7 @@ var cmdTable = []*Command{
 	{"set", setCommand, 2, true},
 	{"get", getCommand, 1, false},
 	{"del", delCommand, 1, true},
+	{"scan", scanCommand, 1, false},
 	{"incr", incrCommand, 1, true},
 	{"hset", hsetCommand, 3, true},
 	{"hget", hgetCommand, 2, false},
@@ -106,32 +109,27 @@ func setCommand(writer *resp.Writer, args []redcon.RESP) {
 
 	for len(extra) > 0 {
 		arg := b2s(extra[0].Bytes())
-
 		// EX
 		if equalFold(arg, EX) && len(extra) >= 2 {
 			n := extra[1].Int()
 			ttl = time.Now().Add(time.Duration(n) * time.Second).UnixNano()
 			extra = extra[2:]
-
 			// PX
 		} else if equalFold(arg, PX) && len(extra) >= 2 {
 			n := extra[1].Int()
 			ttl = time.Now().Add(time.Duration(n) * time.Millisecond).UnixNano()
 			extra = extra[2:]
-
 			// KEEPTTL
 		} else if equalFold(arg, KeepTtl) {
 			extra = extra[1:]
 			ttl = -1
-
 			// NX
 		} else if equalFold(arg, NX) {
 			if _, ttl := db.dict.Get(key); ttl != KeyNotExist {
 				writer.WriteNull()
 				return
 			}
 			extra = extra[1:]
-
 		} else {
 			writer.WriteError(errSyntax.Error())
 			return
@@ -196,6 +194,39 @@ func delCommand(writer *resp.Writer, args []redcon.RESP) {
 	writer.WriteInt(count)
 }
 
+func scanCommand(writer *resp.Writer, args []redcon.RESP) {
+	cursor := int(args[0].Int())
+	count := 10
+	extra := args[1:]
+
+	for len(extra) > 0 {
+		arg := b2s(extra[0].Bytes())
+		// COUNT
+		if equalFold(arg, Count) && len(extra) >= 2 {
+			count = int(extra[1].Int())
+			extra = extra[2:]
+		} else {
+			writer.WriteError(errSyntax.Error())
+			return
+		}
+	}
+
+	keys := make([]string, 0, count)
+	db.dict.data.All(func(key string, _ any) bool {
+		keys = append(keys, key)
+		return count > len(keys)
+	})
+
+	if len(keys) == db.dict.data.Len() {
+		cursor = 0
+	} else {
+		cursor = count
+	}
+	writer.WriteArray(2)
+	writer.WriteInt(cursor)
+	writer.WriteAny(keys)
+}
+
 func hsetCommand(writer *resp.Writer, args []redcon.RESP) {
 	key := args[0].Bytes()
 	args = args[1:]

command_test.go

@@ -422,14 +422,29 @@ func testCommand(t *testing.T, testType string, rdb *redis.Client, sleepFn func(
 		ast.Equal(err.Error(), errWrongType.Error())
 	})
 
-	//t.Run("flushdb", func(t *testing.T) {
-	//	rdb.Set(ctx, "test-flush", "1", 0)
-	//	res, _ := rdb.FlushDB(ctx).Result()
-	//	ast.Equal(res, "OK")
-	//
-	//	_, err := rdb.Get(ctx, "test-flush").Result()
-	//	ast.Equal(err, redis.Nil)
-	//})
+	t.Run("flushdb", func(t *testing.T) {
+		rdb.Set(ctx, "test-flush", "1", 0)
+		res, _ := rdb.FlushDB(ctx).Result()
+		ast.Equal(res, "OK")
+
+		_, err := rdb.Get(ctx, "test-flush").Result()
+		ast.Equal(err, redis.Nil)
+	})
+
+	t.Run("scan", func(t *testing.T) {
+		for i := 0; i < 10; i++ {
+			rdb.Set(ctx, fmt.Sprintf("key-%d", i), 1, 0)
+		}
+		keys, cursor, err := rdb.Scan(ctx, 0, "", 5).Result()
+		ast.Equal(len(keys), 5)
+		ast.Equal(cursor, uint64(5))
+		ast.Nil(err)
+
+		keys, cursor, err = rdb.Scan(ctx, 0, "", 10).Result()
+		ast.Equal(len(keys), 10)
+		ast.Equal(cursor, uint64(0))
+		ast.Nil(err)
+	})
 
 	t.Run("pipline", func(t *testing.T) {
 		pip := rdb.Pipeline()

config.json

@@ -1,5 +1,5 @@
 {
-    "port": 6379,
+    "port": 7799,
     "appendonly": false,
     "appendfilename": "appendonly.aof",
     "save": false,