diff --git a/weed/storage/types/needle_id_type.go b/weed/storage/types/needle_id_type.go
new file mode 100644
index 000000000..d9e7074b3
--- /dev/null
+++ b/weed/storage/types/needle_id_type.go
@@ -0,0 +1,42 @@
+package types
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"strconv"
+	"fmt"
+)
+
+type NeedleId uint64
+
+const (
+	NeedleIdSize = 8
+)
+
+func NeedleIdToBytes(bytes []byte, needleId NeedleId) {
+	util.Uint64toBytes(bytes, uint64(needleId))
+}
+
+// NeedleIdToUint64 used to send max needle id to master
+func NeedleIdToUint64(needleId NeedleId) uint64 {
+	return uint64(needleId)
+}
+
+func Uint64ToNeedleId(needleId uint64) (NeedleId) {
+	return NeedleId(needleId)
+}
+
+func BytesToNeedleId(bytes []byte) (NeedleId) {
+	return NeedleId(util.BytesToUint64(bytes))
+}
+
+func (k NeedleId) String() string {
+	return strconv.FormatUint(uint64(k), 10)
+}
+
+func ParseNeedleId(idString string) (NeedleId, error) {
+	key, err := strconv.ParseUint(idString, 16, 64)
+	if err != nil {
+		return 0, fmt.Errorf("needle id %s format error: %v", idString, err)
+	}
+	return NeedleId(key), nil
+}
diff --git a/weed/storage/types/needle_types.go b/weed/storage/types/needle_types.go
index 0c0b6a7a3..09ff727e6 100644
--- a/weed/storage/types/needle_types.go
+++ b/weed/storage/types/needle_types.go
@@ -7,12 +7,10 @@ import (
 	"fmt"
 )
 
-type NeedleId uint64
 type Offset uint32
 type Cookie uint32
 
 const (
-	NeedleIdSize          = 8
 	OffsetSize            = 4
 	SizeSize              = 4 // uint32 size
 	NeedleEntrySize       = NeedleIdSize + OffsetSize + SizeSize
@@ -22,23 +20,6 @@ const (
 	CookieSize            = 4
 )
 
-func NeedleIdToBytes(bytes []byte, needleId NeedleId) {
-	util.Uint64toBytes(bytes, uint64(needleId))
-}
-
-// NeedleIdToUint64 used to send max needle id to master
-func NeedleIdToUint64(needleId NeedleId) uint64 {
-	return uint64(needleId)
-}
-
-func Uint64ToNeedleId(needleId uint64) (NeedleId) {
-	return NeedleId(needleId)
-}
-
-func BytesToNeedleId(bytes []byte) (NeedleId) {
-	return NeedleId(util.BytesToUint64(bytes))
-}
-
 func CookieToBytes(bytes []byte, cookie Cookie) {
 	util.Uint32toBytes(bytes, uint32(cookie))
 }
@@ -50,6 +31,14 @@ func BytesToCookie(bytes []byte) (Cookie) {
 	return Cookie(util.BytesToUint32(bytes[0:4]))
 }
 
+func ParseCookie(cookieString string) (Cookie, error) {
+	cookie, err := strconv.ParseUint(cookieString, 16, 32)
+	if err != nil {
+		return 0, fmt.Errorf("needle cookie %s format error: %v", cookieString, err)
+	}
+	return Cookie(cookie), nil
+}
+
 func OffsetToBytes(bytes []byte, offset Offset) {
 	util.Uint32toBytes(bytes, uint32(offset))
 }
@@ -61,23 +50,3 @@ func Uint32ToOffset(offset uint32) (Offset) {
 func BytesToOffset(bytes []byte) (Offset) {
 	return Offset(util.BytesToUint32(bytes[0:4]))
 }
-
-func (k NeedleId) String() string {
-	return strconv.FormatUint(uint64(k), 10)
-}
-
-func ParseNeedleId(idString string) (NeedleId, error) {
-	key, err := strconv.ParseUint(idString, 16, 64)
-	if err != nil {
-		return 0, fmt.Errorf("needle id %s format error: %v", idString, err)
-	}
-	return NeedleId(key), nil
-}
-
-func ParseCookie(cookieString string) (Cookie, error) {
-	cookie, err := strconv.ParseUint(cookieString, 16, 32)
-	if err != nil {
-		return 0, fmt.Errorf("needle cookie %s format error: %v", cookieString, err)
-	}
-	return Cookie(cookie), nil
-}