feat: support eval(lua scripts) command

command.go

@@ -10,6 +10,7 @@ import (
 	"github.com/xgzlucario/rotom/internal/hash"
 	"github.com/xgzlucario/rotom/internal/list"
 	"github.com/xgzlucario/rotom/internal/zset"
+	lua "github.com/yuin/gopher-lua"
 )
 
 var (
@@ -58,6 +59,7 @@ var cmdTable []*Command = []*Command{
 	{"zrank", zrankCommand, 2, false},
 	{"zpopmin", zpopminCommand, 1, true},
 	{"zrange", zrangeCommand, 3, false},
+	{"eval", evalCommand, 2, true},
 	{"ping", pingCommand, 0, false},
 	{"flushdb", flushdbCommand, 0, true},
 	// TODO
@@ -537,6 +539,39 @@ func flushdbCommand(writer *RESPWriter, _ []RESP) {
 	writer.WriteString("OK")
 }
 
+func evalCommand(writer *RESPWriter, args []RESP) {
+	L := server.lua
+	script := args[0].ToString()
+
+	numKeys, err := args[1].ToInt()
+	if err != nil {
+		writer.WriteError(err)
+		return
+	}
+
+	// set "KEYS" table
+	table := L.CreateTable(numKeys, 0)
+	for i := range numKeys {
+		table.Append(lua.LString(args[i+2]))
+	}
+	L.SetGlobal("KEYS", table)
+
+	if err := L.DoString(script); err != nil {
+		writer.WriteError(err)
+		return
+	}
+
+	ret := L.Get(-1)
+	switch ret.Type() {
+	case lua.LTString:
+		writer.WriteBulkString(ret.String())
+	case lua.LTNil:
+		writer.WriteNull()
+	default:
+		writer.WriteString("OK")
+	}
+}
+
 func todoCommand(writer *RESPWriter, _ []RESP) {
 	writer.WriteString("OK")
 }

command_test.go

@@ -376,6 +376,22 @@ func TestCommand(t *testing.T) {
 		assert.Equal(err.Error(), errWrongType.Error())
 	})
 
+	t.Run("eval", func(t *testing.T) {
+		keys := []string{"evalKey", "qwer"}
+
+		// set
+		_, err := rdb.Eval(ctx, "call('set',KEYS[0],KEYS[1])", keys).Result()
+		assert.Equal(err, redis.Nil)
+
+		// set with return
+		res, _ := rdb.Eval(ctx, "return call('set',KEYS[0],KEYS[1])", keys).Result()
+		assert.Equal(res, "OK")
+
+		// get
+		res, _ = rdb.Eval(ctx, "return call('get',KEYS[0])", keys[:1]).Result()
+		assert.Equal(res, keys[1])
+	})
+
 	t.Run("flushdb", func(t *testing.T) {
 		rdb.Set(ctx, "test-flush", "1", 0)
 		res, _ := rdb.FlushDB(ctx).Result()

go.mod

@@ -10,7 +10,8 @@ require (
 	github.com/rs/zerolog v1.33.0
 	github.com/stretchr/testify v1.9.0
 	github.com/tidwall/mmap v0.3.0
-	golang.org/x/sys v0.24.0
+	github.com/yuin/gopher-lua v1.1.1
+	golang.org/x/sys v0.25.0
 )
 
 require (

go.sum

@@ -50,15 +50,17 @@ github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsT
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/tidwall/mmap v0.3.0 h1:XXt1YsiXCF5/UAu3pLbu6g7iulJ9jsbs6vt7UpiV0sY=
 github.com/tidwall/mmap v0.3.0/go.mod h1:2/dNzF5zA+te/JVHfrqNLcRkb8LjdH3c80vYHFQEZRk=
+github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M=
+github.com/yuin/gopher-lua v1.1.1/go.mod h1:GBR0iDaNXjAgGg9zfCvksxSRnQx76gclCIb7kdAd1Pw=
 golang.org/x/exp v0.0.0-20180321215751-8460e604b9de/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 h1:2dVuKD2vS7b0QIHQbpyTISPd0LeHDbnYEryqj5Q1ug8=
 golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56/go.mod h1:M4RDyNAINzryxdtnbRXRL/OHtkFuWGRjvuhBJpk2IlY=
 golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.24.0 h1:Twjiwq9dn6R1fQcyiK+wQyHWfaz/BJB+YIpzU/Cv3Xg=
-golang.org/x/sys v0.24.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.25.0 h1:r+8e+loiHxRqhXVl6ML1nO3l1+oFoWbnlu2Ehimmi34=
+golang.org/x/sys v0.25.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/tools v0.0.0-20180525024113-a5b4c53f6e8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 gonum.org/v1/gonum v0.0.0-20181121035319-3f7ecaa7e8ca h1:PupagGYwj8+I4ubCxcmcBRk3VlUWtTg5huQpZR9flmE=
 gonum.org/v1/gonum v0.0.0-20181121035319-3f7ecaa7e8ca/go.mod h1:Y+Yx5eoAFn32cQvJDxZx5Dpnq+c3wtXuadVZAcxbbBo=

lua.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"github.com/xgzlucario/rotom/internal/dict"
+	lua "github.com/yuin/gopher-lua"
+)
+
+func luaCall(L *lua.LState) int {
+	fn := L.ToString(1)
+	keys := L.GetGlobal("KEYS").(*lua.LTable)
+	switch fn {
+	case "set":
+		return luaSet(L, keys)
+	case "get":
+		return luaGet(L, keys)
+	}
+	return -1
+}
+
+func luaSet(L *lua.LState, keys *lua.LTable) int {
+	key := keys.RawGetInt(1).String()
+	value := keys.RawGetInt(2).String()
+	db.dict.Set(key, []byte(value))
+	L.Push(lua.LString("OK"))
+	return 1
+}
+
+func luaGet(L *lua.LState, keys *lua.LTable) int {
+	key := keys.RawGetInt(1).String()
+	value, ttl := db.dict.Get(key)
+	if ttl != dict.KEY_NOT_EXIST {
+		L.Push(lua.LString(value.([]byte)))
+	} else {
+		L.Push(lua.LNil)
+	}
+	return 1
+}

rotom.go

@@ -11,6 +11,7 @@ import (
 	"github.com/xgzlucario/rotom/internal/hash"
 	"github.com/xgzlucario/rotom/internal/list"
 	"github.com/xgzlucario/rotom/internal/zset"
+	lua "github.com/yuin/gopher-lua"
 )
 
 const (
@@ -33,22 +34,20 @@ type DB struct {
 }
 
 type Client struct {
-	fd int
-
-	recvx    int
-	readx    int
-	queryBuf []byte
-
+	fd          int
+	recvx       int
+	readx       int
+	queryBuf    []byte
 	argsBuf     []RESP
 	replyWriter *RESPWriter
 }
 
 type Server struct {
-	fd      int
-	config  *Config
-	aeLoop  *AeLoop
-	clients map[int]*Client
-
+	fd          int
+	config      *Config
+	aeLoop      *AeLoop
+	clients     map[int]*Client
+	lua         *lua.LState
 	outOfMemory bool
 }
 
@@ -215,15 +214,21 @@ func SendReplyToClient(loop *AeLoop, fd int, extra interface{}) {
 func initServer(config *Config) (err error) {
 	server.config = config
 	server.clients = make(map[int]*Client)
+	// init aeloop
 	server.aeLoop, err = AeLoopCreate()
 	if err != nil {
 		return err
 	}
+	// init tcp server
 	server.fd, err = TcpServer(config.Port)
 	if err != nil {
 		Close(server.fd)
 		return err
 	}
+	// init lua state
+	L := lua.NewState()
+	L.SetGlobal("call", L.NewFunction(luaCall))
+	server.lua = L
 	return nil
 }