diff --git a/cmd/ledis-server/main.go b/cmd/ledis-server/main.go
index 5fda7b3..8a76984 100644
--- a/cmd/ledis-server/main.go
+++ b/cmd/ledis-server/main.go
@@ -2,7 +2,7 @@ package main
 
 import (
 	"flag"
-	"github.com/siddontang/ledisdb/ledis"
+	"github.com/siddontang/ledisdb/server"
 	"os"
 	"os/signal"
 	"runtime"
@@ -20,13 +20,13 @@ func main() {
 		panic("must use a config file")
 	}
 
-	cfg, err := ledis.NewConfigWithFile(*configFile)
+	cfg, err := server.NewConfigWithFile(*configFile)
 	if err != nil {
 		panic(err)
 	}
 
-	var app *ledis.App
-	app, err = ledis.NewApp(cfg)
+	var app *server.App
+	app, err = server.NewApp(cfg)
 	if err != nil {
 		panic(err)
 	}
diff --git a/ledis/db_test.go b/ledis/db_test.go
new file mode 100644
index 0000000..683882a
--- /dev/null
+++ b/ledis/db_test.go
@@ -0,0 +1,41 @@
+package ledis
+
+import (
+	"sync"
+	"testing"
+)
+
+var testDB *DB
+var testDBOnce sync.Once
+
+func getTestDB() *DB {
+	f := func() {
+		var d = []byte(`
+            {
+                "data_db" : {
+                    "path" : "/tmp/testdb",
+                    "compression":true,
+                    "block_size" : 32768,
+                    "write_buffer_size" : 2097152,
+                    "cache_size" : 20971520
+                }
+            }
+            `)
+		db, err := OpenDB(d)
+		if err != nil {
+			println(err.Error())
+			panic(err)
+		}
+
+		testDB = db
+
+		testDB.db.Clear()
+	}
+
+	testDBOnce.Do(f)
+	return testDB
+}
+
+func TestDB(t *testing.T) {
+	getTestDB()
+}
diff --git a/ledis/t_hash.go b/ledis/t_hash.go
index 7ed6914..f6e8826 100644
--- a/ledis/t_hash.go
+++ b/ledis/t_hash.go
@@ -21,14 +21,14 @@ const (
 
 func encode_hsize_key(key []byte) []byte {
 	buf := make([]byte, len(key)+1)
-	buf[0] = HSIZE_TYPE
+	buf[0] = hSizeType
 
 	copy(buf[1:], key)
 	return buf
 }
 
 func decode_hsize_key(ek []byte) ([]byte, error) {
-	if len(ek) == 0 || ek[0] != HSIZE_TYPE {
+	if len(ek) == 0 || ek[0] != hSizeType {
 		return nil, errHSizeKey
 	}
 
@@ -39,7 +39,7 @@ func encode_hash_key(key []byte, field []byte) []byte {
 	buf := make([]byte, len(key)+len(field)+1+4+1)
 
 	pos := 0
-	buf[pos] = HASH_TYPE
+	buf[pos] = hashType
 	pos++
 	binary.BigEndian.PutUint32(buf[pos:], uint32(len(key)))
 	pos += 4
@@ -68,7 +68,7 @@ func encode_hash_stop_key(key []byte) []byte {
 }
 
 func decode_hash_key(ek []byte) ([]byte, []byte, error) {
-	if len(ek) < 6 || ek[0] != HASH_TYPE {
+	if len(ek) < 6 || ek[0] != hashType {
 		return nil, nil, errHashKey
 	}
 
diff --git a/ledis/t_kv.go b/ledis/t_kv.go
index f30af86..5df995b 100644
--- a/ledis/t_kv.go
+++ b/ledis/t_kv.go
@@ -13,13 +13,13 @@ var errKVKey = errors.New("invalid encode kv key")
 
 func encode_kv_key(key []byte) []byte {
 	ek := make([]byte, len(key)+1)
-	ek[0] = KV_TYPE
+	ek[0] = kvType
 	copy(ek[1:], key)
 	return ek
 }
 
 func decode_kv_key(ek []byte) ([]byte, error) {
-	if len(ek) == 0 || ek[0] != KV_TYPE {
+	if len(ek) == 0 || ek[0] != kvType {
 		return nil, errKVKey
 	}
 
diff --git a/ledis/t_list.go b/ledis/t_list.go
index ab65c82..2a8aa3e 100644
--- a/ledis/t_list.go
+++ b/ledis/t_list.go
@@ -21,14 +21,14 @@ var errListSeq = errors.New("invalid list sequence, overflow")
 
 func encode_lmeta_key(key []byte) []byte {
 	buf := make([]byte, len(key)+1)
-	buf[0] = LMETA_TYPE
+	buf[0] = lMetaType
 
 	copy(buf[1:], key)
 	return buf
 }
 
 func decode_lmeta_key(ek []byte) ([]byte, error) {
-	if len(ek) == 0 || ek[0] != LMETA_TYPE {
+	if len(ek) == 0 || ek[0] != lMetaType {
 		return nil, errLMetaKey
 	}
 
@@ -39,7 +39,7 @@ func encode_list_key(key []byte, seq int32) []byte {
 	buf := make([]byte, len(key)+9)
 
 	pos := 0
-	buf[pos] = LIST_TYPE
+	buf[pos] = listType
 	pos++
 
 	binary.BigEndian.PutUint32(buf[pos:], uint32(len(key)))
@@ -54,7 +54,7 @@ func encode_list_key(key []byte, seq int32) []byte {
 }
 
 func decode_list_key(ek []byte) (key []byte, seq int32, err error) {
-	if len(ek) < 9 || ek[0] != LIST_TYPE {
+	if len(ek) < 9 || ek[0] != listType {
 		err = errListKey
 		return
 	}
diff --git a/ledis/t_zset.go b/ledis/t_zset.go
index a7b305e..013e66b 100644
--- a/ledis/t_zset.go
+++ b/ledis/t_zset.go
@@ -20,6 +20,7 @@ type ScorePair struct {
 var errZSizeKey = errors.New("invalid zsize key")
 var errZSetKey = errors.New("invalid zset key")
 var errZScoreKey = errors.New("invalid zscore key")
+var errScoreOverflow = errors.New("zset score overflow")
 
 const (
 	zsetNScoreSep    byte = '<'
@@ -32,14 +33,14 @@ const (
 
 func encode_zsize_key(key []byte) []byte {
 	buf := make([]byte, len(key)+1)
-	buf[0] = ZSIZE_TYPE
+	buf[0] = zSizeType
 
 	copy(buf[1:], key)
 	return buf
 }
 
 func decode_zsize_key(ek []byte) ([]byte, error) {
-	if len(ek) == 0 || ek[0] != ZSIZE_TYPE {
+	if len(ek) == 0 || ek[0] != zSizeType {
 		return nil, errZSizeKey
 	}
 
@@ -50,7 +51,7 @@ func encode_zset_key(key []byte, member []byte) []byte {
 	buf := make([]byte, len(key)+len(member)+5)
 
 	pos := 0
-	buf[pos] = ZSET_TYPE
+	buf[pos] = zsetType
 	pos++
 
 	binary.BigEndian.PutUint32(buf[pos:], uint32(len(key)))
@@ -65,7 +66,7 @@ func encode_zset_key(key []byte, member []byte) []byte {
 }
 
 func decode_zset_key(ek []byte) ([]byte, []byte, error) {
-	if len(ek) < 5 || ek[0] != ZSET_TYPE {
+	if len(ek) < 5 || ek[0] != zsetType {
 		return nil, nil, errZSetKey
 	}
 
@@ -83,7 +84,7 @@ func encode_zscore_key(key []byte, member []byte, score int64) []byte {
 	buf := make([]byte, len(key)+len(member)+15)
 
 	pos := 0
-	buf[pos] = ZSCORE_TYPE
+	buf[pos] = zScoreType
 	pos++
 
 	binary.BigEndian.PutUint32(buf[pos:], uint32(len(key)))
@@ -121,7 +122,7 @@ func encode_stop_zscore_key(key []byte, score int64) []byte {
 }
 
 func decode_zscore_key(ek []byte) (key []byte, member []byte, score int64, err error) {
-	if len(ek) < 15 || ek[0] != ZSCORE_TYPE {
+	if len(ek) < 15 || ek[0] != zScoreType {
 		err = errZScoreKey
 		return
 	}
diff --git a/ledis/app.go b/server/app.go
similarity index 86%
rename from ledis/app.go
rename to server/app.go
index 5cbdacd..99e7dce 100644
--- a/ledis/app.go
+++ b/server/app.go
@@ -1,6 +1,7 @@
-package ledis
+package server
 
 import (
+	"github.com/siddontang/ledisdb/ledis"
 	"net"
 	"strings"
 )
@@ -10,7 +11,7 @@ type App struct {
 
 	listener net.Listener
 
-	db *DB
+	db *ledis.DB
 
 	closed bool
 }
@@ -34,7 +35,7 @@ func NewApp(cfg *Config) (*App, error) {
 		return nil, err
 	}
 
-	app.db, err = OpenDBWithConfig(&cfg.DB)
+	app.db, err = ledis.OpenDBWithConfig(&cfg.DB)
 	if err != nil {
 		return nil, err
 	}
diff --git a/ledis/app_test.go b/server/app_test.go
similarity index 94%
rename from ledis/app_test.go
rename to server/app_test.go
index c80fccb..2293ce2 100644
--- a/ledis/app_test.go
+++ b/server/app_test.go
@@ -1,4 +1,4 @@
-package ledis
+package server
 
 import (
 	"github.com/garyburd/redigo/redis"
@@ -30,12 +30,6 @@ func getTestConn() redis.Conn {
 	return testPool.Get()
 }
 
-func getTestDB() *DB {
-	startTestApp()
-
-	return testApp.db
-}
-
 func startTestApp() {
 	f := func() {
 		newTestRedisPool()
diff --git a/ledis/client.go b/server/client.go
similarity index 86%
rename from ledis/client.go
rename to server/client.go
index 6b9b1ed..f89f38e 100644
--- a/ledis/client.go
+++ b/server/client.go
@@ -1,9 +1,10 @@
-package ledis
+package server
 
 import (
 	"bufio"
 	"errors"
 	"github.com/siddontang/golib/log"
+	"github.com/siddontang/ledisdb/ledis"
 	"io"
 	"net"
 	"runtime"
@@ -14,7 +15,7 @@ import (
 var errReadRequest = errors.New("invalid request protocol")
 
 type client struct {
-	db *DB
+	db *ledis.DB
 	c  net.Conn
 
 	rb *bufio.Reader
@@ -26,7 +27,7 @@ type client struct {
 	reqC chan error
 }
 
-func newClient(c net.Conn, db *DB) {
+func newClient(c net.Conn, db *ledis.DB) {
 	co := new(client)
 	co.db = db
 	co.c = c
@@ -91,7 +92,7 @@ func (c *client) readRequest() ([][]byte, error) {
 	}
 
 	var nparams int
-	if nparams, err = strconv.Atoi(String(l[1:])); err != nil {
+	if nparams, err = strconv.Atoi(ledis.String(l[1:])); err != nil {
 		return nil, err
 	} else if nparams <= 0 {
 		return nil, errReadRequest
@@ -108,7 +109,7 @@ func (c *client) readRequest() ([][]byte, error) {
 			return nil, errReadRequest
 		} else if l[0] == '$' {
 			//handle resp string
-			if n, err = strconv.Atoi(String(l[1:])); err != nil {
+			if n, err = strconv.Atoi(ledis.String(l[1:])); err != nil {
 				return nil, err
 			} else if n == -1 {
 				req = append(req, nil)
@@ -138,7 +139,7 @@ func (c *client) handleRequest(req [][]byte) {
 	if len(req) == 0 {
 		err = ErrEmptyCommand
 	} else {
-		c.cmd = strings.ToLower(String(req[0]))
+		c.cmd = strings.ToLower(ledis.String(req[0]))
 		c.args = req[1:]
 
 		f, ok := regCmds[c.cmd]
@@ -160,23 +161,23 @@ func (c *client) handleRequest(req [][]byte) {
 }
 
 func (c *client) writeError(err error) {
-	c.wb.Write(Slice("-ERR"))
+	c.wb.Write(ledis.Slice("-ERR"))
 	if err != nil {
 		c.wb.WriteByte(' ')
-		c.wb.Write(Slice(err.Error()))
+		c.wb.Write(ledis.Slice(err.Error()))
 	}
 	c.wb.Write(Delims)
 }
 
 func (c *client) writeStatus(status string) {
 	c.wb.WriteByte('+')
-	c.wb.Write(Slice(status))
+	c.wb.Write(ledis.Slice(status))
 	c.wb.Write(Delims)
 }
 
 func (c *client) writeInteger(n int64) {
 	c.wb.WriteByte(':')
-	c.wb.Write(StrPutInt64(n))
+	c.wb.Write(ledis.StrPutInt64(n))
 	c.wb.Write(Delims)
 }
 
@@ -185,7 +186,7 @@ func (c *client) writeBulk(b []byte) {
 	if b == nil {
 		c.wb.Write(NullBulk)
 	} else {
-		c.wb.Write(Slice(strconv.Itoa(len(b))))
+		c.wb.Write(ledis.Slice(strconv.Itoa(len(b))))
 		c.wb.Write(Delims)
 		c.wb.Write(b)
 	}
@@ -199,7 +200,7 @@ func (c *client) writeArray(ay []interface{}) {
 		c.wb.Write(NullArray)
 		c.wb.Write(Delims)
 	} else {
-		c.wb.Write(Slice(strconv.Itoa(len(ay))))
+		c.wb.Write(ledis.Slice(strconv.Itoa(len(ay))))
 		c.wb.Write(Delims)
 
 		for i := 0; i < len(ay); i++ {
diff --git a/ledis/cmd_hash.go b/server/cmd_hash.go
similarity index 95%
rename from ledis/cmd_hash.go
rename to server/cmd_hash.go
index 1fe2c18..b86e339 100644
--- a/ledis/cmd_hash.go
+++ b/server/cmd_hash.go
@@ -1,6 +1,8 @@
-package ledis
+package server
 
-import ()
+import (
+	"github.com/siddontang/ledisdb/ledis"
+)
 
 func hsetCommand(c *client) error {
 	args := c.args
@@ -87,7 +89,7 @@ func hincrbyCommand(c *client) error {
 		return ErrCmdParams
 	}
 
-	delta, err := StrInt64(args[2], nil)
+	delta, err := ledis.StrInt64(args[2], nil)
 	if err != nil {
 		return err
 	}
@@ -115,7 +117,7 @@ func hmsetCommand(c *client) error {
 
 	args = args[1:]
 
-	kvs := make([]FVPair, len(args)/2)
+	kvs := make([]ledis.FVPair, len(args)/2)
 	for i := 0; i < len(kvs); i++ {
 		kvs[i].Field = args[2*i]
 		kvs[i].Value = args[2*i+1]
diff --git a/ledis/cmd_hash_test.go b/server/cmd_hash_test.go
similarity index 99%
rename from ledis/cmd_hash_test.go
rename to server/cmd_hash_test.go
index e292cd3..26b0b47 100644
--- a/ledis/cmd_hash_test.go
+++ b/server/cmd_hash_test.go
@@ -1,4 +1,4 @@
-package ledis
+package server
 
 import (
 	"fmt"
diff --git a/ledis/cmd_kv.go b/server/cmd_kv.go
similarity index 94%
rename from ledis/cmd_kv.go
rename to server/cmd_kv.go
index b41f853..a6bdcbd 100644
--- a/ledis/cmd_kv.go
+++ b/server/cmd_kv.go
@@ -1,6 +1,8 @@
-package ledis
+package server
 
-import ()
+import (
+	"github.com/siddontang/ledisdb/ledis"
+)
 
 func getCommand(c *client) error {
 	args := c.args
@@ -112,7 +114,7 @@ func incrbyCommand(c *client) error {
 		return ErrCmdParams
 	}
 
-	delta, err := StrInt64(args[1], nil)
+	delta, err := ledis.StrInt64(args[1], nil)
 	if err != nil {
 		return err
 	}
@@ -132,7 +134,7 @@ func decrbyCommand(c *client) error {
 		return ErrCmdParams
 	}
 
-	delta, err := StrInt64(args[1], nil)
+	delta, err := ledis.StrInt64(args[1], nil)
 	if err != nil {
 		return err
 	}
@@ -167,7 +169,7 @@ func msetCommand(c *client) error {
 		return ErrCmdParams
 	}
 
-	kvs := make([]KVPair, len(args)/2)
+	kvs := make([]ledis.KVPair, len(args)/2)
 	for i := 0; i < len(kvs); i++ {
 		kvs[i].Key = args[2*i]
 		kvs[i].Value = args[2*i+1]
diff --git a/ledis/cmd_kv_test.go b/server/cmd_kv_test.go
similarity index 99%
rename from ledis/cmd_kv_test.go
rename to server/cmd_kv_test.go
index ced52b7..8318a97 100644
--- a/ledis/cmd_kv_test.go
+++ b/server/cmd_kv_test.go
@@ -1,4 +1,4 @@
-package ledis
+package server
 
 import (
 	"github.com/garyburd/redigo/redis"
diff --git a/ledis/cmd_list.go b/server/cmd_list.go
similarity index 91%
rename from ledis/cmd_list.go
rename to server/cmd_list.go
index 18847ef..193e27d 100644
--- a/ledis/cmd_list.go
+++ b/server/cmd_list.go
@@ -1,6 +1,8 @@
-package ledis
+package server
 
-import ()
+import (
+	"github.com/siddontang/ledisdb/ledis"
+)
 
 func lpushCommand(c *client) error {
 	args := c.args
@@ -83,7 +85,7 @@ func lindexCommand(c *client) error {
 		return ErrCmdParams
 	}
 
-	index, err := StrInt64(args[1], nil)
+	index, err := ledis.StrInt64(args[1], nil)
 	if err != nil {
 		return err
 	}
@@ -107,12 +109,12 @@ func lrangeCommand(c *client) error {
 	var stop int64
 	var err error
 
-	start, err = StrInt64(args[1], nil)
+	start, err = ledis.StrInt64(args[1], nil)
 	if err != nil {
 		return err
 	}
 
-	stop, err = StrInt64(args[2], nil)
+	stop, err = ledis.StrInt64(args[2], nil)
 	if err != nil {
 		return err
 	}
diff --git a/ledis/cmd_list_test.go b/server/cmd_list_test.go
similarity index 99%
rename from ledis/cmd_list_test.go
rename to server/cmd_list_test.go
index 5b40fb3..58bab33 100644
--- a/ledis/cmd_list_test.go
+++ b/server/cmd_list_test.go
@@ -1,4 +1,4 @@
-package ledis
+package server
 
 import (
 	"fmt"
diff --git a/ledis/cmd_zset.go b/server/cmd_zset.go
similarity index 86%
rename from ledis/cmd_zset.go
rename to server/cmd_zset.go
index f30f8de..c7f26b5 100644
--- a/ledis/cmd_zset.go
+++ b/server/cmd_zset.go
@@ -1,7 +1,8 @@
-package ledis
+package server
 
 import (
 	"errors"
+	"github.com/siddontang/ledisdb/ledis"
 	"math"
 	"strconv"
 	"strings"
@@ -24,9 +25,9 @@ func zaddCommand(c *client) error {
 
 	args = args[1:]
 
-	params := make([]ScorePair, len(args)/2)
+	params := make([]ledis.ScorePair, len(args)/2)
 	for i := 0; i < len(params); i++ {
-		score, err := StrInt64(args[2*i], nil)
+		score, err := ledis.StrInt64(args[2*i], nil)
 		if err != nil {
 			return err
 		}
@@ -97,7 +98,7 @@ func zincrbyCommand(c *client) error {
 
 	key := args[0]
 
-	delta, err := StrInt64(args[1], nil)
+	delta, err := ledis.StrInt64(args[1], nil)
 	if err != nil {
 		return err
 	}
@@ -112,7 +113,7 @@ func zincrbyCommand(c *client) error {
 }
 
 func zparseScoreRange(minBuf []byte, maxBuf []byte) (min int64, max int64, err error) {
-	if strings.ToLower(String(minBuf)) == "-inf" {
+	if strings.ToLower(ledis.String(minBuf)) == "-inf" {
 		min = math.MinInt64
 	} else {
 		var lopen bool = false
@@ -126,12 +127,12 @@ func zparseScoreRange(minBuf []byte, maxBuf []byte) (min int64, max int64, err e
 			return
 		}
 
-		min, err = StrInt64(minBuf, nil)
+		min, err = ledis.StrInt64(minBuf, nil)
 		if err != nil {
 			return
 		}
 
-		if min <= MinScore || min >= MaxScore {
+		if min <= ledis.MinScore || min >= ledis.MaxScore {
 			err = errScoreOverflow
 			return
 		}
@@ -141,7 +142,7 @@ func zparseScoreRange(minBuf []byte, maxBuf []byte) (min int64, max int64, err e
 		}
 	}
 
-	if strings.ToLower(String(maxBuf)) == "+inf" {
+	if strings.ToLower(ledis.String(maxBuf)) == "+inf" {
 		max = math.MaxInt64
 	} else {
 		var ropen = false
@@ -155,12 +156,12 @@ func zparseScoreRange(minBuf []byte, maxBuf []byte) (min int64, max int64, err e
 			return
 		}
 
-		max, err = StrInt64(maxBuf, nil)
+		max, err = ledis.StrInt64(maxBuf, nil)
 		if err != nil {
 			return
 		}
 
-		if max <= MinScore || max >= MaxScore {
+		if max <= ledis.MinScore || max >= ledis.MaxScore {
 			err = errScoreOverflow
 			return
 		}
@@ -276,11 +277,11 @@ func zremrangebyscoreCommand(c *client) error {
 }
 
 func zparseRange(c *client, a1 []byte, a2 []byte) (start int, stop int, err error) {
-	if start, err = strconv.Atoi(String(a1)); err != nil {
+	if start, err = strconv.Atoi(ledis.String(a1)); err != nil {
 		return
 	}
 
-	if stop, err = strconv.Atoi(String(a2)); err != nil {
+	if stop, err = strconv.Atoi(ledis.String(a2)); err != nil {
 		return
 	}
 
@@ -303,7 +304,7 @@ func zrangeGeneric(c *client, reverse bool) error {
 	args = args[3:]
 	var withScores bool = false
 
-	if len(args) > 0 && strings.ToLower(String(args[0])) == "withscores" {
+	if len(args) > 0 && strings.ToLower(ledis.String(args[0])) == "withscores" {
 		withScores = true
 	}
 
@@ -339,7 +340,7 @@ func zrangebyscoreGeneric(c *client, reverse bool) error {
 
 	var withScores bool = false
 
-	if len(args) > 0 && strings.ToLower(String(args[0])) == "withscores" {
+	if len(args) > 0 && strings.ToLower(ledis.String(args[0])) == "withscores" {
 		withScores = true
 		args = args[1:]
 	}
@@ -352,15 +353,15 @@ func zrangebyscoreGeneric(c *client, reverse bool) error {
 			return ErrCmdParams
 		}
 
-		if strings.ToLower(String(args[0])) != "limit" {
+		if strings.ToLower(ledis.String(args[0])) != "limit" {
 			return ErrCmdParams
 		}
 
-		if offset, err = strconv.Atoi(String(args[1])); err != nil {
+		if offset, err = strconv.Atoi(ledis.String(args[1])); err != nil {
 			return ErrCmdParams
 		}
 
-		if count, err = strconv.Atoi(String(args[2])); err != nil {
+		if count, err = strconv.Atoi(ledis.String(args[2])); err != nil {
 			return ErrCmdParams
 		}
 	}
diff --git a/ledis/cmd_zset_test.go b/server/cmd_zset_test.go
similarity index 90%
rename from ledis/cmd_zset_test.go
rename to server/cmd_zset_test.go
index e8d4b11..8ac59ab 100644
--- a/ledis/cmd_zset_test.go
+++ b/server/cmd_zset_test.go
@@ -1,61 +1,12 @@
-package ledis
+package server
 
 import (
-	"bytes"
 	"fmt"
 	"github.com/garyburd/redigo/redis"
 	"strconv"
 	"testing"
 )
 
-func TestCodecZSet(t *testing.T) {
-	key := []byte("a")
-
-	ek := encode_zsize_key(key)
-
-	if k, err := decode_zsize_key(ek); err != nil {
-		t.Fatal(err)
-	} else if !bytes.Equal(key, k) {
-		t.Fatal(string(k))
-	}
-
-	member := []byte("f")
-
-	ek = encode_zset_key(key, member)
-
-	if k, m, err := decode_zset_key(ek); err != nil {
-		t.Fatal(err)
-	} else if !bytes.Equal(key, k) {
-		t.Fatal(string(k))
-	} else if !bytes.Equal(member, m) {
-		t.Fatal(string(m))
-	}
-
-	ek = encode_zscore_key(key, member, 3)
-
-	if k, m, s, err := decode_zscore_key(ek); err != nil {
-		t.Fatal(err)
-	} else if !bytes.Equal(key, k) {
-		t.Fatal(string(k))
-	} else if !bytes.Equal(member, m) {
-		t.Fatal(string(m))
-	} else if s != 3 {
-		t.Fatal(s)
-	}
-
-	ek = encode_zscore_key(key, member, -3)
-
-	if k, m, s, err := decode_zscore_key(ek); err != nil {
-		t.Fatal(err)
-	} else if !bytes.Equal(key, k) {
-		t.Fatal(string(k))
-	} else if !bytes.Equal(member, m) {
-		t.Fatal(string(m))
-	} else if s != -3 {
-		t.Fatal(s)
-	}
-}
-
 func TestZSet(t *testing.T) {
 	c := getTestConn()
 	defer c.Close()
diff --git a/ledis/command.go b/server/command.go
similarity index 97%
rename from ledis/command.go
rename to server/command.go
index 39a855f..0a64810 100644
--- a/ledis/command.go
+++ b/server/command.go
@@ -1,4 +1,4 @@
-package ledis
+package server
 
 import (
 	"fmt"
diff --git a/ledis/config.go b/server/config.go
similarity index 83%
rename from ledis/config.go
rename to server/config.go
index 78abf7d..ee9b503 100644
--- a/ledis/config.go
+++ b/server/config.go
@@ -1,14 +1,15 @@
-package ledis
+package server
 
 import (
 	"encoding/json"
+	"github.com/siddontang/ledisdb/ledis"
 	"io/ioutil"
 )
 
 type Config struct {
 	Addr string `json:"addr"`
 
-	DB DBConfig `json:"db"`
+	DB ledis.DBConfig `json:"db"`
 }
 
 func NewConfig(data json.RawMessage) (*Config, error) {
diff --git a/ledis/const.go b/server/const.go
similarity index 69%
rename from ledis/const.go
rename to server/const.go
index 235053f..36235a8 100644
--- a/ledis/const.go
+++ b/server/const.go
@@ -1,4 +1,4 @@
-package ledis
+package server
 
 import (
 	"errors"
@@ -19,14 +19,3 @@ var (
 	PONG = "PONG"
 	OK   = "OK"
 )
-
-const (
-	KV_TYPE byte = iota + 1
-	HASH_TYPE
-	HSIZE_TYPE
-	LIST_TYPE
-	LMETA_TYPE
-	ZSET_TYPE
-	ZSIZE_TYPE
-	ZSCORE_TYPE
-)