diff --git a/bootstrap.sh b/bootstrap.sh
index fffd283..b121d0d 100644
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -3,7 +3,6 @@
 . ./dev.sh
 
 go get -u github.com/jmhodges/levigo 
-go get -u github.com/siddontang/golib/leveldb 
+go get -u github.com/siddontang/go-leveldb/leveldb 
 go get -u github.com/siddontang/golib/log 
-go get -u github.com/siddontang/golib/hack 
 go get -u github.com/garyburd/redigo/redis
diff --git a/ledis/app.go b/ledis/app.go
index 50f0481..a0a6757 100644
--- a/ledis/app.go
+++ b/ledis/app.go
@@ -1,7 +1,7 @@
 package ledis
 
 import (
-	"github.com/siddontang/golib/leveldb"
+	"github.com/siddontang/go-leveldb/leveldb"
 	"net"
 	"strings"
 )
diff --git a/ledis/client.go b/ledis/client.go
index 6a49429..c71d16a 100644
--- a/ledis/client.go
+++ b/ledis/client.go
@@ -3,7 +3,6 @@ package ledis
 import (
 	"bufio"
 	"errors"
-	"github.com/siddontang/golib/hack"
 	"github.com/siddontang/golib/log"
 	"io"
 	"net"
@@ -92,7 +91,7 @@ func (c *client) readRequest() ([][]byte, error) {
 	}
 
 	var nparams int
-	if nparams, err = strconv.Atoi(hack.String(l[1:])); err != nil {
+	if nparams, err = strconv.Atoi(String(l[1:])); err != nil {
 		return nil, err
 	} else if nparams <= 0 {
 		return nil, errReadRequest
@@ -109,7 +108,7 @@ func (c *client) readRequest() ([][]byte, error) {
 			return nil, errReadRequest
 		} else if l[0] == '$' {
 			//handle resp string
-			if n, err = strconv.Atoi(hack.String(l[1:])); err != nil {
+			if n, err = strconv.Atoi(String(l[1:])); err != nil {
 				return nil, err
 			} else if n == -1 {
 				req = append(req, nil)
@@ -139,7 +138,7 @@ func (c *client) handleRequest(req [][]byte) {
 	if len(req) == 0 {
 		err = ErrEmptyCommand
 	} else {
-		c.cmd = strings.ToLower(hack.String(req[0]))
+		c.cmd = strings.ToLower(String(req[0]))
 		c.args = req[1:]
 
 		f, ok := regCmds[c.cmd]
@@ -161,23 +160,23 @@ func (c *client) handleRequest(req [][]byte) {
 }
 
 func (c *client) writeError(err error) {
-	c.wb.Write(hack.Slice("-ERR"))
+	c.wb.Write(Slice("-ERR"))
 	if err != nil {
 		c.wb.WriteByte(' ')
-		c.wb.Write(hack.Slice(err.Error()))
+		c.wb.Write(Slice(err.Error()))
 	}
 	c.wb.Write(Delims)
 }
 
 func (c *client) writeStatus(status string) {
 	c.wb.WriteByte('+')
-	c.wb.Write(hack.Slice(status))
+	c.wb.Write(Slice(status))
 	c.wb.Write(Delims)
 }
 
 func (c *client) writeInteger(n int64) {
 	c.wb.WriteByte(':')
-	c.wb.Write(hack.Slice(strconv.FormatInt(n, 10)))
+	c.wb.Write(Slice(strconv.FormatInt(n, 10)))
 	c.wb.Write(Delims)
 }
 
@@ -186,7 +185,7 @@ func (c *client) writeBulk(b []byte) {
 	if b == nil {
 		c.wb.Write(NullBulk)
 	} else {
-		c.wb.Write(hack.Slice(strconv.Itoa(len(b))))
+		c.wb.Write(Slice(strconv.Itoa(len(b))))
 		c.wb.Write(Delims)
 		c.wb.Write(b)
 	}
@@ -200,7 +199,7 @@ func (c *client) writeArray(ay []interface{}) {
 		c.wb.Write(NullArray)
 		c.wb.Write(Delims)
 	} else {
-		c.wb.Write(hack.Slice(strconv.Itoa(len(ay))))
+		c.wb.Write(Slice(strconv.Itoa(len(ay))))
 		c.wb.Write(Delims)
 
 		for i := 0; i < len(ay); i++ {
diff --git a/ledis/cmd_hash.go b/ledis/cmd_hash.go
index 91cc192..86b424f 100644
--- a/ledis/cmd_hash.go
+++ b/ledis/cmd_hash.go
@@ -1,9 +1,6 @@
 package ledis
 
-import (
-	"github.com/siddontang/golib/hack"
-	"strconv"
-)
+import ()
 
 func hsetCommand(c *client) error {
 	args := c.args
@@ -90,7 +87,7 @@ func hincrbyCommand(c *client) error {
 		return ErrCmdParams
 	}
 
-	delta, err := strconv.ParseInt(hack.String(args[2]), 10, 64)
+	delta, err := StrInt64(args[2], nil)
 	if err != nil {
 		return err
 	}
diff --git a/ledis/cmd_kv.go b/ledis/cmd_kv.go
index d7a08b5..381ec8c 100644
--- a/ledis/cmd_kv.go
+++ b/ledis/cmd_kv.go
@@ -1,9 +1,6 @@
 package ledis
 
-import (
-	"github.com/siddontang/golib/hack"
-	"strconv"
-)
+import ()
 
 func getCommand(c *client) error {
 	args := c.args
@@ -115,7 +112,7 @@ func incrbyCommand(c *client) error {
 		return ErrCmdParams
 	}
 
-	delta, err := strconv.ParseInt(hack.String(args[1]), 10, 64)
+	delta, err := StrInt64(args[1], nil)
 	if err != nil {
 		return err
 	}
@@ -135,7 +132,7 @@ func decrbyCommand(c *client) error {
 		return ErrCmdParams
 	}
 
-	delta, err := strconv.ParseInt(hack.String(args[1]), 10, 64)
+	delta, err := StrInt64(args[1], nil)
 	if err != nil {
 		return err
 	}
diff --git a/ledis/cmd_list.go b/ledis/cmd_list.go
index 09ed7a0..e41f520 100644
--- a/ledis/cmd_list.go
+++ b/ledis/cmd_list.go
@@ -1,9 +1,6 @@
 package ledis
 
-import (
-	"github.com/siddontang/golib/hack"
-	"strconv"
-)
+import ()
 
 func lpushCommand(c *client) error {
 	args := c.args
@@ -86,7 +83,7 @@ func lindexCommand(c *client) error {
 		return ErrCmdParams
 	}
 
-	index, err := strconv.ParseInt(hack.String(args[1]), 10, 64)
+	index, err := StrInt64(args[1], nil)
 	if err != nil {
 		return err
 	}
@@ -110,12 +107,12 @@ func lrangeCommand(c *client) error {
 	var stop int64
 	var err error
 
-	start, err = strconv.ParseInt(hack.String(args[1]), 10, 64)
+	start, err = StrInt64(args[1], nil)
 	if err != nil {
 		return err
 	}
 
-	stop, err = strconv.ParseInt(hack.String(args[2]), 10, 64)
+	stop, err = StrInt64(args[2], nil)
 	if err != nil {
 		return err
 	}
diff --git a/ledis/cmd_zset.go b/ledis/cmd_zset.go
index 4035629..4f84e24 100644
--- a/ledis/cmd_zset.go
+++ b/ledis/cmd_zset.go
@@ -2,7 +2,6 @@ package ledis
 
 import (
 	"errors"
-	"github.com/siddontang/golib/hack"
 	"math"
 	"strconv"
 	"strings"
@@ -31,7 +30,7 @@ func zaddCommand(c *client) error {
 	args = args[1:]
 	params := make([]interface{}, len(args))
 	for i := 0; i < len(params); i += 2 {
-		score, err := strconv.ParseInt(hack.String(args[i]), 10, 64)
+		score, err := StrInt64(args[i], nil)
 		if err != nil {
 			return err
 		}
@@ -102,7 +101,7 @@ func zincrbyCommand(c *client) error {
 
 	key := args[0]
 
-	delta, err := strconv.ParseInt(hack.String(args[1]), 10, 64)
+	delta, err := StrInt64(args[1], nil)
 	if err != nil {
 		return err
 	}
@@ -117,7 +116,7 @@ func zincrbyCommand(c *client) error {
 }
 
 func zparseScoreRange(minBuf []byte, maxBuf []byte) (min int64, max int64, err error) {
-	if strings.ToLower(hack.String(minBuf)) == "-inf" {
+	if strings.ToLower(String(minBuf)) == "-inf" {
 		min = math.MinInt64
 	} else {
 		var lopen bool = false
@@ -131,7 +130,7 @@ func zparseScoreRange(minBuf []byte, maxBuf []byte) (min int64, max int64, err e
 			return
 		}
 
-		min, err = strconv.ParseInt(hack.String(minBuf), 10, 64)
+		min, err = StrInt64(minBuf, nil)
 		if err != nil {
 			return
 		}
@@ -146,7 +145,7 @@ func zparseScoreRange(minBuf []byte, maxBuf []byte) (min int64, max int64, err e
 		}
 	}
 
-	if strings.ToLower(hack.String(maxBuf)) == "+inf" {
+	if strings.ToLower(String(maxBuf)) == "+inf" {
 		max = math.MaxInt64
 	} else {
 		var ropen = false
@@ -160,7 +159,7 @@ func zparseScoreRange(minBuf []byte, maxBuf []byte) (min int64, max int64, err e
 			return
 		}
 
-		max, err = strconv.ParseInt(hack.String(maxBuf), 10, 64)
+		max, err = StrInt64(maxBuf, nil)
 		if err != nil {
 			return
 		}
@@ -288,11 +287,11 @@ func zremrangebyscoreCommand(c *client) error {
 func zparseRange(c *client, key []byte, startBuf []byte, stopBuf []byte) (offset int, limit int, err error) {
 	var start int
 	var stop int
-	if start, err = strconv.Atoi(hack.String(startBuf)); err != nil {
+	if start, err = strconv.Atoi(String(startBuf)); err != nil {
 		return
 	}
 
-	if stop, err = strconv.Atoi(hack.String(stopBuf)); err != nil {
+	if stop, err = strconv.Atoi(String(stopBuf)); err != nil {
 		return
 	}
 
@@ -354,7 +353,7 @@ func zrangeGeneric(c *client, reverse bool) error {
 	args = args[3:]
 	var withScores bool = false
 
-	if len(args) > 0 && strings.ToLower(hack.String(args[0])) == "withscores" {
+	if len(args) > 0 && strings.ToLower(String(args[0])) == "withscores" {
 		withScores = true
 	}
 
@@ -390,7 +389,7 @@ func zrangebyscoreGeneric(c *client, reverse bool) error {
 
 	var withScores bool = false
 
-	if len(args) > 0 && strings.ToLower(hack.String(args[0])) == "withscores" {
+	if len(args) > 0 && strings.ToLower(String(args[0])) == "withscores" {
 		withScores = true
 		args = args[1:]
 	}
@@ -403,15 +402,15 @@ func zrangebyscoreGeneric(c *client, reverse bool) error {
 			return ErrCmdParams
 		}
 
-		if strings.ToLower(hack.String(args[0])) != "limit" {
+		if strings.ToLower(String(args[0])) != "limit" {
 			return ErrCmdParams
 		}
 
-		if offset, err = strconv.Atoi(hack.String(args[1])); err != nil {
+		if offset, err = strconv.Atoi(String(args[1])); err != nil {
 			return ErrCmdParams
 		}
 
-		if limit, err = strconv.Atoi(hack.String(args[2])); err != nil {
+		if limit, err = strconv.Atoi(String(args[2])); err != nil {
 			return ErrCmdParams
 		}
 	}
diff --git a/ledis/config.go b/ledis/config.go
index a303a73..9172e77 100644
--- a/ledis/config.go
+++ b/ledis/config.go
@@ -2,7 +2,7 @@ package ledis
 
 import (
 	"encoding/json"
-	"github.com/siddontang/golib/leveldb"
+	"github.com/siddontang/go-leveldb/leveldb"
 	"io/ioutil"
 )
 
diff --git a/ledis/t_hash.go b/ledis/t_hash.go
index 2c4d488..55a2568 100644
--- a/ledis/t_hash.go
+++ b/ledis/t_hash.go
@@ -3,9 +3,7 @@ package ledis
 import (
 	"encoding/binary"
 	"errors"
-	"github.com/siddontang/golib/hack"
-	"github.com/siddontang/golib/leveldb"
-	"strconv"
+	"github.com/siddontang/go-leveldb/leveldb"
 )
 
 var errHashKey = errors.New("invalid hash key")
@@ -90,26 +88,21 @@ func decode_hash_key(ek []byte) ([]byte, []byte, error) {
 }
 
 func (a *App) hash_len(key []byte) (int64, error) {
-	return a.db.GetInt(encode_hsize_key(key))
+	return Int64(a.db.Get(encode_hsize_key(key)))
 }
 
 func (a *App) hash_setItem(key []byte, field []byte, value []byte) (int64, error) {
 	t := a.hashTx
 
 	ek := encode_hash_key(key, field)
-	sk := encode_hsize_key(key)
-
-	size, err := a.db.GetInt(sk)
-	if err != nil {
-		return 0, err
-	}
 
 	var n int64 = 1
 	if v, _ := a.db.Get(ek); v != nil {
 		n = 0
 	} else {
-		size++
-		t.Put(sk, hack.Slice(strconv.FormatInt(size, 10)))
+		if _, err := a.hash_incrSize(key, 1); err != nil {
+			return 0, err
+		}
 	}
 
 	t.Put(ek, value)
@@ -137,30 +130,26 @@ func (a *App) hash_get(key []byte, field []byte) ([]byte, error) {
 }
 
 func (a *App) hash_mset(key []byte, args [][]byte) error {
-	sk := encode_hsize_key(key)
-
 	t := a.hashTx
 	t.Lock()
 	defer t.Unlock()
 
-	size, err := a.db.GetInt(sk)
-	if err != nil {
-		return err
-	}
-
+	var num int64 = 0
 	for i := 0; i < len(args); i += 2 {
 		ek := encode_hash_key(key, args[i])
 		if v, _ := a.db.Get(ek); v == nil {
-			size++
+			num++
 		}
 
 		t.Put(ek, args[i+1])
 	}
 
-	t.Put(sk, hack.Slice(strconv.FormatInt(size, 10)))
+	if _, err := a.hash_incrSize(key, num); err != nil {
+		return err
+	}
 
 	//todo add binglog
-	err = t.Commit()
+	err := t.Commit()
 	return err
 }
 
@@ -179,17 +168,10 @@ func (a *App) hash_mget(key []byte, args [][]byte) ([]interface{}, error) {
 }
 
 func (a *App) hash_del(key []byte, args [][]byte) (int64, error) {
-	sk := encode_hsize_key(key)
-
 	t := a.hashTx
 	t.Lock()
 	defer t.Unlock()
 
-	size, err := a.db.GetInt(sk)
-	if err != nil {
-		return 0, err
-	}
-
 	var num int64 = 0
 	for i := 0; i < len(args); i++ {
 		ek := encode_hash_key(key, args[i])
@@ -199,22 +181,38 @@ func (a *App) hash_del(key []byte, args [][]byte) (int64, error) {
 			continue
 		} else {
 			num++
-			size--
 			t.Delete(ek)
 		}
 	}
 
-	if size <= 0 {
-		t.Delete(sk)
-	} else {
-		t.Put(sk, hack.Slice(strconv.FormatInt(size, 10)))
+	if _, err := a.hash_incrSize(key, -num); err != nil {
+		return 0, err
 	}
 
-	err = t.Commit()
+	err := t.Commit()
 
 	return num, err
 }
 
+func (a *App) hash_incrSize(key []byte, delta int64) (int64, error) {
+	t := a.hashTx
+	sk := encode_hsize_key(key)
+	size, err := Int64(a.db.Get(sk))
+	if err != nil {
+		return 0, err
+	} else {
+		size += delta
+		if size <= 0 {
+			size = 0
+			t.Delete(sk)
+		} else {
+			t.Put(sk, PutInt64(size))
+		}
+	}
+
+	return size, nil
+}
+
 func (a *App) hash_incrby(key []byte, field []byte, delta int64) (int64, error) {
 	t := a.hashTx
 	t.Lock()
@@ -223,18 +221,14 @@ func (a *App) hash_incrby(key []byte, field []byte, delta int64) (int64, error)
 	ek := encode_hash_key(key, field)
 
 	var n int64 = 0
-	v, err := a.db.Get(ek)
+	n, err := StrInt64(a.db.Get(ek))
 	if err != nil {
 		return 0, err
-	} else if v != nil {
-		if n, err = strconv.ParseInt(hack.String(v), 10, 64); err != nil {
-			return 0, err
-		}
 	}
 
 	n += delta
 
-	_, err = a.hash_setItem(key, field, hack.Slice(strconv.FormatInt(n, 10)))
+	_, err = a.hash_setItem(key, field, StrPutInt64(n))
 	if err != nil {
 		return 0, err
 	}
diff --git a/ledis/t_kv.go b/ledis/t_kv.go
index f575e6d..2fd146f 100644
--- a/ledis/t_kv.go
+++ b/ledis/t_kv.go
@@ -2,8 +2,6 @@ package ledis
 
 import (
 	"errors"
-	"github.com/siddontang/golib/hack"
-	"strconv"
 )
 
 var errKVKey = errors.New("invalid encode kv key")
@@ -117,14 +115,14 @@ func (a *App) kv_incr(key []byte, delta int64) (int64, error) {
 	defer t.Unlock()
 
 	var n int64
-	n, err = a.db.GetInt(key)
+	n, err = StrInt64(a.db.Get(key))
 	if err != nil {
 		return 0, err
 	}
 
 	n += delta
 
-	t.Put(key, hack.Slice(strconv.FormatInt(n, 10)))
+	t.Put(key, StrPutInt64(n))
 
 	//todo binlog
 
diff --git a/ledis/t_list.go b/ledis/t_list.go
index 8515b8d..af6f484 100644
--- a/ledis/t_list.go
+++ b/ledis/t_list.go
@@ -3,7 +3,7 @@ package ledis
 import (
 	"encoding/binary"
 	"errors"
-	"github.com/siddontang/golib/leveldb"
+	"github.com/siddontang/go-leveldb/leveldb"
 )
 
 const (
diff --git a/ledis/t_zset.go b/ledis/t_zset.go
index 6635e1d..ea0fae0 100644
--- a/ledis/t_zset.go
+++ b/ledis/t_zset.go
@@ -4,8 +4,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"errors"
-	"github.com/siddontang/golib/hack"
-	"github.com/siddontang/golib/leveldb"
+	"github.com/siddontang/go-leveldb/leveldb"
 	"strconv"
 )
 
@@ -262,7 +261,7 @@ func (a *App) zset_score(key []byte, member []byte) ([]byte, error) {
 		return nil, err
 	}
 
-	return hack.Slice(strconv.FormatInt(score, 10)), nil
+	return Slice(strconv.FormatInt(score, 10)), nil
 }
 
 func (a *App) zset_rem(key []byte, args [][]byte) (int64, error) {
@@ -319,7 +318,7 @@ func (a *App) zset_incrby(key []byte, delta int64, member []byte) ([]byte, error
 	t.Put(encode_zscore_key(key, member, score), []byte{})
 
 	err = t.Commit()
-	return hack.Slice(strconv.FormatInt(score, 10)), err
+	return Slice(strconv.FormatInt(score, 10)), err
 }
 
 func (a *App) zset_count(key []byte, min int64, max int64) (int64, error) {
@@ -471,7 +470,7 @@ func (a *App) zset_range(key []byte, min int64, max int64, withScores bool, offs
 		v = append(v, m)
 
 		if withScores {
-			v = append(v, hack.Slice(strconv.FormatInt(s, 10)))
+			v = append(v, Slice(strconv.FormatInt(s, 10)))
 		}
 	}
 
diff --git a/ledis/tx.go b/ledis/tx.go
index 35c5180..41d0133 100644
--- a/ledis/tx.go
+++ b/ledis/tx.go
@@ -1,7 +1,7 @@
 package ledis
 
 import (
-	"github.com/siddontang/golib/leveldb"
+	"github.com/siddontang/go-leveldb/leveldb"
 	"sync"
 )
 
diff --git a/ledis/util.go b/ledis/util.go
index e5d6efd..a5a1289 100644
--- a/ledis/util.go
+++ b/ledis/util.go
@@ -3,11 +3,34 @@ package ledis
 import (
 	"encoding/binary"
 	"errors"
-	"github.com/siddontang/golib/hack"
+	"reflect"
+	"strconv"
+	"unsafe"
 )
 
 var errIntNumber = errors.New("invalid integer")
 
+// no copy to change slice to string
+// use your own risk
+func String(b []byte) (s string) {
+	pbytes := (*reflect.SliceHeader)(unsafe.Pointer(&b))
+	pstring := (*reflect.StringHeader)(unsafe.Pointer(&s))
+	pstring.Data = pbytes.Data
+	pstring.Len = pbytes.Len
+	return
+}
+
+// no copy to change string to slice
+// use your own risk
+func Slice(s string) (b []byte) {
+	pbytes := (*reflect.SliceHeader)(unsafe.Pointer(&b))
+	pstring := (*reflect.StringHeader)(unsafe.Pointer(&s))
+	pbytes.Data = pstring.Data
+	pbytes.Len = pstring.Len
+	pbytes.Cap = pstring.Len
+	return
+}
+
 func Int64(v []byte, err error) (int64, error) {
 	if err != nil {
 		return 0, err
@@ -21,9 +44,24 @@ func Int64(v []byte, err error) (int64, error) {
 }
 
 func PutInt64(v int64) []byte {
-	return hack.Int64Slice(v)
+	var b []byte
+	pbytes := (*reflect.SliceHeader)(unsafe.Pointer(&b))
+	pbytes.Data = uintptr(unsafe.Pointer(&v))
+	pbytes.Len = 8
+	pbytes.Cap = 8
+	return b
 }
 
-func PutInt32(v int32) []byte {
-	return hack.Int32Slice(v)
+func StrInt64(v []byte, err error) (int64, error) {
+	if err != nil {
+		return 0, err
+	} else if v == nil {
+		return 0, nil
+	} else {
+		return strconv.ParseInt(String(v), 10, 64)
+	}
+}
+
+func StrPutInt64(v int64) []byte {
+	return Slice(strconv.FormatInt(v, 10))
 }