From 1321c63f3b70368ff75b358d01c649172a72f368 Mon Sep 17 00:00:00 2001
From: Ben Johnson <benbjohnson@yahoo.com>
Date: Mon, 14 Oct 2013 11:12:30 -0600
Subject: [PATCH] Extract Store into an interface.

---
 server/peer_server.go         |  4 +--
 server/registry.go            |  4 +--
 server/server.go              |  6 ++--
 server/v1/v1.go               |  2 +-
 server/v2/v2.go               |  2 +-
 store/create_command.go       |  2 +-
 store/delete_command.go       |  2 +-
 store/node.go                 | 38 +++++++++++---------
 store/stats_test.go           |  4 +--
 store/store.go                | 68 ++++++++++++++++++++++-------------
 store/store_test.go           | 22 ++++++------
 store/test_and_set_command.go |  2 +-
 store/update_command.go       |  2 +-
 store/watcher_test.go         |  2 +-
 14 files changed, 92 insertions(+), 68 deletions(-)

diff --git a/server/peer_server.go b/server/peer_server.go
index 942d9e062..97a7757a3 100644
--- a/server/peer_server.go
+++ b/server/peer_server.go
@@ -30,7 +30,7 @@ type PeerServer struct {
 	followersStats *raftFollowersStats
 	serverStats    *raftServerStats
 	registry       *Registry
-	store          *store.Store
+	store          store.Store
 	snapConf       *snapshotConf
 	MaxClusterSize int
 	RetryTimes     int
@@ -49,7 +49,7 @@ type snapshotConf struct {
 	writesThr uint64
 }
 
-func NewPeerServer(name string, path string, url string, listenHost string, tlsConf *TLSConfig, tlsInfo *TLSInfo, registry *Registry, store *store.Store) *PeerServer {
+func NewPeerServer(name string, path string, url string, listenHost string, tlsConf *TLSConfig, tlsInfo *TLSInfo, registry *Registry, store store.Store) *PeerServer {
 	s := &PeerServer{
 		name:       name,
 		url:        url,
diff --git a/server/registry.go b/server/registry.go
index b9197436b..23ef9ddbb 100644
--- a/server/registry.go
+++ b/server/registry.go
@@ -18,7 +18,7 @@ const RegistryKey = "/_etcd/machines"
 // The Registry stores URL information for nodes.
 type Registry struct {
 	sync.Mutex
-	store *store.Store
+	store store.Store
 	nodes map[string]*node
 }
 
@@ -30,7 +30,7 @@ type node struct {
 }
 
 // Creates a new Registry.
-func NewRegistry(s *store.Store) *Registry {
+func NewRegistry(s store.Store) *Registry {
 	return &Registry{
 		store: s,
 		nodes: make(map[string]*node),
diff --git a/server/server.go b/server/server.go
index 24064fa4e..4e21aa179 100644
--- a/server/server.go
+++ b/server/server.go
@@ -21,7 +21,7 @@ type Server struct {
 	http.Server
 	peerServer  *PeerServer
 	registry    *Registry
-	store       *store.Store
+	store       store.Store
 	name        string
 	url         string
 	tlsConf     *TLSConfig
@@ -30,7 +30,7 @@ type Server struct {
 }
 
 // Creates a new Server.
-func New(name string, urlStr string, listenHost string, tlsConf *TLSConfig, tlsInfo *TLSInfo, peerServer *PeerServer, registry *Registry, store *store.Store) *Server {
+func New(name string, urlStr string, listenHost string, tlsConf *TLSConfig, tlsInfo *TLSInfo, peerServer *PeerServer, registry *Registry, store store.Store) *Server {
 	s := &Server{
 		Server: http.Server{
 			Handler:   mux.NewRouter(),
@@ -85,7 +85,7 @@ func (s *Server) PeerURL(name string) (string, bool) {
 }
 
 // Returns a reference to the Store.
-func (s *Server) Store() *store.Store {
+func (s *Server) Store() store.Store {
 	return s.store
 }
 
diff --git a/server/v1/v1.go b/server/v1/v1.go
index f71ed0622..6b155b7cc 100644
--- a/server/v1/v1.go
+++ b/server/v1/v1.go
@@ -10,6 +10,6 @@ import (
 type Server interface {
 	CommitIndex() uint64
 	Term() uint64
-	Store() *store.Store
+	Store() store.Store
 	Dispatch(raft.Command, http.ResponseWriter, *http.Request) error
 }
diff --git a/server/v2/v2.go b/server/v2/v2.go
index e412e859b..019297331 100644
--- a/server/v2/v2.go
+++ b/server/v2/v2.go
@@ -13,6 +13,6 @@ type Server interface {
 	CommitIndex() uint64
 	Term() uint64
 	PeerURL(string) (string, bool)
-	Store() *store.Store
+	Store() store.Store
 	Dispatch(raft.Command, http.ResponseWriter, *http.Request) error
 }
diff --git a/store/create_command.go b/store/create_command.go
index 2ccddd103..f13b91790 100644
--- a/store/create_command.go
+++ b/store/create_command.go
@@ -26,7 +26,7 @@ func (c *CreateCommand) CommandName() string {
 
 // Create node
 func (c *CreateCommand) Apply(server *raft.Server) (interface{}, error) {
-	s, _ := server.StateMachine().(*Store)
+	s, _ := server.StateMachine().(Store)
 
 	e, err := s.Create(c.Key, c.Value, c.IncrementalSuffix, c.Force, c.ExpireTime, server.CommitIndex(), server.Term())
 
diff --git a/store/delete_command.go b/store/delete_command.go
index 324410192..bc84dfc99 100644
--- a/store/delete_command.go
+++ b/store/delete_command.go
@@ -22,7 +22,7 @@ func (c *DeleteCommand) CommandName() string {
 
 // Delete the key
 func (c *DeleteCommand) Apply(server *raft.Server) (interface{}, error) {
-	s, _ := server.StateMachine().(*Store)
+	s, _ := server.StateMachine().(Store)
 
 	e, err := s.Delete(c.Key, c.Recursive, server.CommitIndex(), server.Term())
 
diff --git a/store/node.go b/store/node.go
index 683e6038b..bbb971bd4 100644
--- a/store/node.go
+++ b/store/node.go
@@ -36,6 +36,9 @@ type Node struct {
 	Value      string           // for key-value pair
 	Children   map[string]*Node // for directory
 
+	// A reference to the store this node is attached to.
+	store *store
+
 	// a ttl node will have an expire routine associated with it.
 	// we need a channel to stop that routine when the expiration changes.
 	stopExpire chan bool
@@ -46,7 +49,7 @@ type Node struct {
 }
 
 // newKV creates a Key-Value pair
-func newKV(nodePath string, value string, createIndex uint64,
+func newKV(store *store, nodePath string, value string, createIndex uint64,
 	createTerm uint64, parent *Node, ACL string, expireTime time.Time) *Node {
 
 	return &Node{
@@ -57,6 +60,7 @@ func newKV(nodePath string, value string, createIndex uint64,
 		ModifiedTerm:  createTerm,
 		Parent:        parent,
 		ACL:           ACL,
+		store:         store,
 		stopExpire:    make(chan bool, 1),
 		ExpireTime:    expireTime,
 		Value:         value,
@@ -64,7 +68,7 @@ func newKV(nodePath string, value string, createIndex uint64,
 }
 
 // newDir creates a directory
-func newDir(nodePath string, createIndex uint64, createTerm uint64,
+func newDir(store *store, nodePath string, createIndex uint64, createTerm uint64,
 	parent *Node, ACL string, expireTime time.Time) *Node {
 
 	return &Node{
@@ -76,6 +80,7 @@ func newDir(nodePath string, createIndex uint64, createTerm uint64,
 		stopExpire:  make(chan bool, 1),
 		ExpireTime:  expireTime,
 		Children:    make(map[string]*Node),
+		store:       store,
 	}
 }
 
@@ -262,17 +267,17 @@ func (n *Node) internalRemove(recursive bool, callback func(path string)) {
 // if the node is already expired, delete the node and return.
 // if the node is permanent (this shouldn't happen), return at once.
 // else wait for a period time, then remove the node. and notify the watchhub.
-func (n *Node) Expire(s *Store) {
+func (n *Node) Expire() {
 	expired, duration := n.IsExpired()
 
 	if expired { // has been expired
 		// since the parent function of Expire() runs serially,
 		// there is no need for lock here
 		e := newEvent(Expire, n.Path, UndefIndex, UndefTerm)
-		s.WatcherHub.notify(e)
+		n.store.WatcherHub.notify(e)
 
 		n.Remove(true, nil)
-		s.Stats.Inc(ExpireCount)
+		n.store.Stats.Inc(ExpireCount)
 
 		return
 	}
@@ -289,17 +294,17 @@ func (n *Node) Expire(s *Store) {
 			// before expire get the lock, the expiration time
 			// of the node may be updated.
 			// we have to check again when get the lock
-			s.worldLock.Lock()
-			defer s.worldLock.Unlock()
+			n.store.worldLock.Lock()
+			defer n.store.worldLock.Unlock()
 
 			expired, _ := n.IsExpired()
 
 			if expired {
 				e := newEvent(Expire, n.Path, UndefIndex, UndefTerm)
-				s.WatcherHub.notify(e)
+				n.store.WatcherHub.notify(e)
 
 				n.Remove(true, nil)
-				s.Stats.Inc(ExpireCount)
+				n.store.Stats.Inc(ExpireCount)
 			}
 
 			return
@@ -355,7 +360,7 @@ func (n *Node) Pair(recurisive, sorted bool) KeyValuePair {
 	}
 }
 
-func (n *Node) UpdateTTL(expireTime time.Time, s *Store) {
+func (n *Node) UpdateTTL(expireTime time.Time) {
 	if !n.IsPermanent() {
 		// check if the node has been expired
 		// if the node is not expired, we need to stop the go routine associated with
@@ -369,7 +374,7 @@ func (n *Node) UpdateTTL(expireTime time.Time, s *Store) {
 
 	if expireTime.Sub(Permanent) != 0 {
 		n.ExpireTime = expireTime
-		n.Expire(s)
+		n.Expire()
 	}
 }
 
@@ -378,10 +383,10 @@ func (n *Node) UpdateTTL(expireTime time.Time, s *Store) {
 // If the node is a key-value pair, it will clone the pair.
 func (n *Node) Clone() *Node {
 	if !n.IsDir() {
-		return newKV(n.Path, n.Value, n.CreateIndex, n.CreateTerm, n.Parent, n.ACL, n.ExpireTime)
+		return newKV(n.store, n.Path, n.Value, n.CreateIndex, n.CreateTerm, n.Parent, n.ACL, n.ExpireTime)
 	}
 
-	clone := newDir(n.Path, n.CreateIndex, n.CreateTerm, n.Parent, n.ACL, n.ExpireTime)
+	clone := newDir(n.store, n.Path, n.CreateIndex, n.CreateTerm, n.Parent, n.ACL, n.ExpireTime)
 
 	for key, child := range n.Children {
 		clone.Children[key] = child.Clone()
@@ -397,15 +402,16 @@ func (n *Node) Clone() *Node {
 // call this function on its children.
 // We check the expire last since we need to recover the whole structure first and add all the
 // notifications into the event history.
-func (n *Node) recoverAndclean(s *Store) {
+func (n *Node) recoverAndclean() {
 	if n.IsDir() {
 		for _, child := range n.Children {
 			child.Parent = n
-			child.recoverAndclean(s)
+			child.store = n.store
+			child.recoverAndclean()
 		}
 	}
 
 	n.stopExpire = make(chan bool, 1)
 
-	n.Expire(s)
+	n.Expire()
 }
diff --git a/store/stats_test.go b/store/stats_test.go
index deeb317dc..44d1a8999 100644
--- a/store/stats_test.go
+++ b/store/stats_test.go
@@ -7,7 +7,7 @@ import (
 )
 
 func TestBasicStats(t *testing.T) {
-	s := New()
+	s := newStore()
 	keys := GenKeys(rand.Intn(100), 5)
 
 	var i uint64
@@ -140,7 +140,7 @@ func TestBasicStats(t *testing.T) {
 		t.Fatalf("TestAndSetFail [%d] != Stats.TestAndSetFail [%d]", TestAndSetFail, s.Stats.TestAndSetFail)
 	}
 
-	s = New()
+	s = newStore()
 	SetSuccess = 0
 	SetFail = 0
 
diff --git a/store/store.go b/store/store.go
index ade44acd9..60eb35da5 100644
--- a/store/store.go
+++ b/store/store.go
@@ -13,7 +13,21 @@ import (
 	etcdErr "github.com/coreos/etcd/error"
 )
 
-type Store struct {
+type Store interface {
+	Get(nodePath string, recursive, sorted bool, index uint64, term uint64) (*Event, error)
+	Create(nodePath string, value string, incrementalSuffix bool, force bool,
+		expireTime time.Time, index uint64, term uint64) (*Event, error)
+	Update(nodePath string, newValue string, expireTime time.Time, index uint64, term uint64) (*Event, error)
+	TestAndSet(nodePath string, prevValue string, prevIndex uint64,
+		value string, expireTime time.Time, index uint64, term uint64) (*Event, error)
+	Delete(nodePath string, recursive bool, index uint64, term uint64) (*Event, error)
+	Watch(prefix string, recursive bool, sinceIndex uint64, index uint64, term uint64) (<-chan *Event, error)
+	Save() ([]byte, error)
+	Recovery(state []byte) error
+	JsonStats() []byte
+}
+
+type store struct {
 	Root       *Node
 	WatcherHub *watcherHub
 	Index      uint64
@@ -22,9 +36,13 @@ type Store struct {
 	worldLock  sync.RWMutex // stop the world lock
 }
 
-func New() *Store {
-	s := new(Store)
-	s.Root = newDir("/", UndefIndex, UndefTerm, nil, "", Permanent)
+func New() Store {
+	return newStore()
+}
+
+func newStore() *store {
+	s := new(store)
+	s.Root = newDir(s, "/", UndefIndex, UndefTerm, nil, "", Permanent)
 	s.Stats = newStats()
 	s.WatcherHub = newWatchHub(1000)
 
@@ -34,7 +52,7 @@ func New() *Store {
 // Get function returns a get event.
 // If recursive is true, it will return all the content under the node path.
 // If sorted is true, it will sort the content by keys.
-func (s *Store) Get(nodePath string, recursive, sorted bool, index uint64, term uint64) (*Event, error) {
+func (s *store) Get(nodePath string, recursive, sorted bool, index uint64, term uint64) (*Event, error) {
 	s.worldLock.RLock()
 	defer s.worldLock.RUnlock()
 
@@ -89,7 +107,7 @@ func (s *Store) Get(nodePath string, recursive, sorted bool, index uint64, term
 // Create function creates the Node at nodePath. Create will help to create intermediate directories with no ttl.
 // If the node has already existed, create will fail.
 // If any node on the path is a file, create will fail.
-func (s *Store) Create(nodePath string, value string, incrementalSuffix bool, force bool,
+func (s *store) Create(nodePath string, value string, incrementalSuffix bool, force bool,
 	expireTime time.Time, index uint64, term uint64) (*Event, error) {
 	nodePath = path.Clean(path.Join("/", nodePath))
 
@@ -101,7 +119,7 @@ func (s *Store) Create(nodePath string, value string, incrementalSuffix bool, fo
 // Update function updates the value/ttl of the node.
 // If the node is a file, the value and the ttl can be updated.
 // If the node is a directory, only the ttl can be updated.
-func (s *Store) Update(nodePath string, newValue string, expireTime time.Time, index uint64, term uint64) (*Event, error) {
+func (s *store) Update(nodePath string, newValue string, expireTime time.Time, index uint64, term uint64) (*Event, error) {
 	s.worldLock.Lock()
 	defer s.worldLock.Unlock()
 	nodePath = path.Clean(path.Join("/", nodePath))
@@ -127,7 +145,7 @@ func (s *Store) Update(nodePath string, newValue string, expireTime time.Time, i
 	}
 
 	// update ttl
-	n.UpdateTTL(expireTime, s)
+	n.UpdateTTL(expireTime)
 
 	e.Expiration, e.TTL = n.ExpirationAndTTL()
 
@@ -138,7 +156,7 @@ func (s *Store) Update(nodePath string, newValue string, expireTime time.Time, i
 	return e, nil
 }
 
-func (s *Store) TestAndSet(nodePath string, prevValue string, prevIndex uint64,
+func (s *store) TestAndSet(nodePath string, prevValue string, prevIndex uint64,
 	value string, expireTime time.Time, index uint64, term uint64) (*Event, error) {
 
 	nodePath = path.Clean(path.Join("/", nodePath))
@@ -168,7 +186,7 @@ func (s *Store) TestAndSet(nodePath string, prevValue string, prevIndex uint64,
 
 		// if test succeed, write the value
 		n.Write(value, index, term)
-		n.UpdateTTL(expireTime, s)
+		n.UpdateTTL(expireTime)
 
 		e.Value = value
 		e.Expiration, e.TTL = n.ExpirationAndTTL()
@@ -185,7 +203,7 @@ func (s *Store) TestAndSet(nodePath string, prevValue string, prevIndex uint64,
 
 // Delete function deletes the node at the given path.
 // If the node is a directory, recursive must be true to delete it.
-func (s *Store) Delete(nodePath string, recursive bool, index uint64, term uint64) (*Event, error) {
+func (s *store) Delete(nodePath string, recursive bool, index uint64, term uint64) (*Event, error) {
 	nodePath = path.Clean(path.Join("/", nodePath))
 
 	s.worldLock.Lock()
@@ -224,7 +242,7 @@ func (s *Store) Delete(nodePath string, recursive bool, index uint64, term uint6
 	return e, nil
 }
 
-func (s *Store) Watch(prefix string, recursive bool, sinceIndex uint64, index uint64, term uint64) (<-chan *Event, error) {
+func (s *store) Watch(prefix string, recursive bool, sinceIndex uint64, index uint64, term uint64) (<-chan *Event, error) {
 	prefix = path.Clean(path.Join("/", prefix))
 
 	s.worldLock.RLock()
@@ -252,7 +270,7 @@ func (s *Store) Watch(prefix string, recursive bool, sinceIndex uint64, index ui
 }
 
 // walk function walks all the nodePath and apply the walkFunc on each directory
-func (s *Store) walk(nodePath string, walkFunc func(prev *Node, component string) (*Node, *etcdErr.Error)) (*Node, *etcdErr.Error) {
+func (s *store) walk(nodePath string, walkFunc func(prev *Node, component string) (*Node, *etcdErr.Error)) (*Node, *etcdErr.Error) {
 	components := strings.Split(nodePath, "/")
 
 	curr := s.Root
@@ -273,7 +291,7 @@ func (s *Store) walk(nodePath string, walkFunc func(prev *Node, component string
 	return curr, nil
 }
 
-func (s *Store) internalCreate(nodePath string, value string, incrementalSuffix bool, force bool,
+func (s *store) internalCreate(nodePath string, value string, incrementalSuffix bool, force bool,
 	expireTime time.Time, index uint64, term uint64, action string) (*Event, error) {
 
 	s.Index, s.Term = index, term
@@ -316,12 +334,12 @@ func (s *Store) internalCreate(nodePath string, value string, incrementalSuffix
 	if len(value) != 0 { // create file
 		e.Value = value
 
-		n = newKV(nodePath, value, index, term, d, "", expireTime)
+		n = newKV(s, nodePath, value, index, term, d, "", expireTime)
 
 	} else { // create directory
 		e.Dir = true
 
-		n = newDir(nodePath, index, term, d, "", expireTime)
+		n = newDir(s, nodePath, index, term, d, "", expireTime)
 
 	}
 
@@ -334,7 +352,7 @@ func (s *Store) internalCreate(nodePath string, value string, incrementalSuffix
 
 	// Node with TTL
 	if expireTime.Sub(Permanent) != 0 {
-		n.Expire(s)
+		n.Expire()
 		e.Expiration, e.TTL = n.ExpirationAndTTL()
 	}
 
@@ -344,7 +362,7 @@ func (s *Store) internalCreate(nodePath string, value string, incrementalSuffix
 }
 
 // InternalGet function get the node of the given nodePath.
-func (s *Store) internalGet(nodePath string, index uint64, term uint64) (*Node, *etcdErr.Error) {
+func (s *store) internalGet(nodePath string, index uint64, term uint64) (*Node, *etcdErr.Error) {
 	nodePath = path.Clean(path.Join("/", nodePath))
 
 	// update file system known index and term
@@ -379,7 +397,7 @@ func (s *Store) internalGet(nodePath string, index uint64, term uint64) (*Node,
 // If it is a directory, this function will return the pointer to that node.
 // If it does not exist, this function will create a new directory and return the pointer to that node.
 // If it is a file, this function will return error.
-func (s *Store) checkDir(parent *Node, dirName string) (*Node, *etcdErr.Error) {
+func (s *store) checkDir(parent *Node, dirName string) (*Node, *etcdErr.Error) {
 	node, ok := parent.Children[dirName]
 
 	if ok {
@@ -390,7 +408,7 @@ func (s *Store) checkDir(parent *Node, dirName string) (*Node, *etcdErr.Error) {
 		return nil, etcdErr.NewError(etcdErr.EcodeNotDir, parent.Path, UndefIndex, UndefTerm)
 	}
 
-	n := newDir(path.Join(parent.Path, dirName), s.Index, s.Term, parent, parent.ACL, Permanent)
+	n := newDir(s, path.Join(parent.Path, dirName), s.Index, s.Term, parent, parent.ACL, Permanent)
 
 	parent.Children[dirName] = n
 
@@ -401,10 +419,10 @@ func (s *Store) checkDir(parent *Node, dirName string) (*Node, *etcdErr.Error) {
 // Save function will not be able to save the state of watchers.
 // Save function will not save the parent field of the node. Or there will
 // be cyclic dependencies issue for the json package.
-func (s *Store) Save() ([]byte, error) {
+func (s *store) Save() ([]byte, error) {
 	s.worldLock.Lock()
 
-	clonedStore := New()
+	clonedStore := newStore()
 	clonedStore.Index = s.Index
 	clonedStore.Term = s.Term
 	clonedStore.Root = s.Root.Clone()
@@ -426,7 +444,7 @@ func (s *Store) Save() ([]byte, error) {
 // It needs to recovery the parent field of the nodes.
 // It needs to delete the expired nodes since the saved time and also
 // need to create monitor go routines.
-func (s *Store) Recovery(state []byte) error {
+func (s *store) Recovery(state []byte) error {
 	s.worldLock.Lock()
 	defer s.worldLock.Unlock()
 	err := json.Unmarshal(state, s)
@@ -435,11 +453,11 @@ func (s *Store) Recovery(state []byte) error {
 		return err
 	}
 
-	s.Root.recoverAndclean(s)
+	s.Root.recoverAndclean()
 	return nil
 }
 
-func (s *Store) JsonStats() []byte {
+func (s *store) JsonStats() []byte {
 	s.Stats.Watchers = uint64(s.WatcherHub.count)
 	return s.Stats.toJson()
 }
diff --git a/store/store_test.go b/store/store_test.go
index 74add4424..958d99007 100644
--- a/store/store_test.go
+++ b/store/store_test.go
@@ -8,7 +8,7 @@ import (
 )
 
 func TestCreateAndGet(t *testing.T) {
-	s := New()
+	s := newStore()
 
 	s.Create("/foobar", "bar", false, false, Permanent, 1, 1)
 
@@ -66,7 +66,7 @@ func TestCreateAndGet(t *testing.T) {
 }
 
 func TestUpdateFile(t *testing.T) {
-	s := New()
+	s := newStore()
 
 	_, err := s.Create("/foo/bar", "bar", false, false, Permanent, 1, 1)
 
@@ -161,7 +161,7 @@ func TestUpdateFile(t *testing.T) {
 }
 
 func TestListDirectory(t *testing.T) {
-	s := New()
+	s := newStore()
 
 	// create dir /foo
 	// set key-value /foo/foo=bar
@@ -206,7 +206,7 @@ func TestListDirectory(t *testing.T) {
 }
 
 func TestRemove(t *testing.T) {
-	s := New()
+	s := newStore()
 
 	s.Create("/foo", "bar", false, false, Permanent, 1, 1)
 	_, err := s.Delete("/foo", false, 1, 1)
@@ -245,7 +245,7 @@ func TestRemove(t *testing.T) {
 }
 
 func TestExpire(t *testing.T) {
-	s := New()
+	s := newStore()
 
 	expire := time.Now().Add(time.Second)
 
@@ -287,7 +287,7 @@ func TestExpire(t *testing.T) {
 }
 
 func TestTestAndSet(t *testing.T) { // TODO prevValue == nil ?
-	s := New()
+	s := newStore()
 	s.Create("/foo", "bar", false, false, Permanent, 1, 1)
 
 	// test on wrong previous value
@@ -320,7 +320,7 @@ func TestTestAndSet(t *testing.T) { // TODO prevValue == nil ?
 }
 
 func TestWatch(t *testing.T) {
-	s := New()
+	s := newStore()
 	// watch at a deeper path
 	c, _ := s.Watch("/foo/foo/foo", false, 0, 0, 1)
 	s.Create("/foo/foo/foo", "bar", false, false, Permanent, 1, 1)
@@ -409,7 +409,7 @@ func TestWatch(t *testing.T) {
 }
 
 func TestSort(t *testing.T) {
-	s := New()
+	s := newStore()
 
 	// simulating random creation
 	keys := GenKeys(80, 4)
@@ -447,7 +447,7 @@ func TestSort(t *testing.T) {
 }
 
 func TestSaveAndRecover(t *testing.T) {
-	s := New()
+	s := newStore()
 
 	// simulating random creation
 	keys := GenKeys(8, 4)
@@ -469,7 +469,7 @@ func TestSaveAndRecover(t *testing.T) {
 	s.Create("/foo/foo", "bar", false, false, expire, 1, 1)
 	b, err := s.Save()
 
-	cloneFs := New()
+	cloneFs := newStore()
 	time.Sleep(2 * time.Second)
 
 	cloneFs.Recovery(b)
@@ -521,7 +521,7 @@ func GenKeys(num int, depth int) []string {
 	return keys
 }
 
-func createAndGet(s *Store, path string, t *testing.T) {
+func createAndGet(s *store, path string, t *testing.T) {
 	_, err := s.Create(path, "bar", false, false, Permanent, 1, 1)
 
 	if err != nil {
diff --git a/store/test_and_set_command.go b/store/test_and_set_command.go
index 3370fed15..811f713e5 100644
--- a/store/test_and_set_command.go
+++ b/store/test_and_set_command.go
@@ -27,7 +27,7 @@ func (c *TestAndSetCommand) CommandName() string {
 
 // Set the key-value pair if the current value of the key equals to the given prevValue
 func (c *TestAndSetCommand) Apply(server *raft.Server) (interface{}, error) {
-	s, _ := server.StateMachine().(*Store)
+	s, _ := server.StateMachine().(Store)
 
 	e, err := s.TestAndSet(c.Key, c.PrevValue, c.PrevIndex,
 		c.Value, c.ExpireTime, server.CommitIndex(), server.Term())
diff --git a/store/update_command.go b/store/update_command.go
index 9ffd6c868..582fb42fe 100644
--- a/store/update_command.go
+++ b/store/update_command.go
@@ -25,7 +25,7 @@ func (c *UpdateCommand) CommandName() string {
 
 // Update node
 func (c *UpdateCommand) Apply(server *raft.Server) (interface{}, error) {
-	s, _ := server.StateMachine().(*Store)
+	s, _ := server.StateMachine().(Store)
 
 	e, err := s.Update(c.Key, c.Value, c.ExpireTime, server.CommitIndex(), server.Term())
 
diff --git a/store/watcher_test.go b/store/watcher_test.go
index e437422ad..61da92f7c 100644
--- a/store/watcher_test.go
+++ b/store/watcher_test.go
@@ -5,7 +5,7 @@ import (
 )
 
 func TestWatcher(t *testing.T) {
-	s := New()
+	s := newStore()
 	wh := s.WatcherHub
 	c, err := wh.watch("/foo", true, 1)
 	if err != nil {