update sessionRelease

1. mysql fix last access time not update
2. mysql & redid Release when data is empty
3. add maxlifetime distinct Gclifetime

@@ -34,10 +34,3 @@ More info [beego.me](http://beego.me)
 
 beego is licensed under the Apache Licence, Version 2.0
 (http://www.apache.org/licenses/LICENSE-2.0.html).
-
-
-## Use case
-
-- Displaying API documentation: [gowalker](https://github.com/Unknwon/gowalker)
-- seocms: [seocms](https://github.com/chinakr/seocms)
-- CMS: [toropress](https://github.com/insionng/toropress)

@@ -63,13 +63,13 @@ func (st *MysqlSessionStore) SessionID() string {
 
 func (st *MysqlSessionStore) SessionRelease(w http.ResponseWriter) {
 	defer st.c.Close()
-	if len(st.values) > 0 {
-		b, err := encodeGob(st.values)
-		if err != nil {
-			return
-		}
-		st.c.Exec("UPDATE session set `session_data`= ? where session_key=?", b, st.sid)
+	b, err := encodeGob(st.values)
+	if err != nil {
+		return
 	}
+	st.c.Exec("UPDATE session set `session_data`=?, `session_expiry`=? where session_key=?",
+		b, time.Now().Unix(), st.sid)
+
 }
 
 type MysqlProvider struct {
@@ -97,7 +97,8 @@ func (mp *MysqlProvider) SessionRead(sid string) (SessionStore, error) {
 	var sessiondata []byte
 	err := row.Scan(&sessiondata)
 	if err == sql.ErrNoRows {
-		c.Exec("insert into session(`session_key`,`session_data`,`session_expiry`) values(?,?,?)", sid, "", time.Now().Unix())
+		c.Exec("insert into session(`session_key`,`session_data`,`session_expiry`) values(?,?,?)",
+			sid, "", time.Now().Unix())
 	}
 	var kv map[interface{}]interface{}
 	if len(sessiondata) == 0 {

@@ -61,14 +61,12 @@ func (rs *RedisSessionStore) SessionID() string {
 
 func (rs *RedisSessionStore) SessionRelease(w http.ResponseWriter) {
 	defer rs.c.Close()
-	if len(rs.values) > 0 {
-		b, err := encodeGob(rs.values)
-		if err != nil {
-			return
-		}
-		rs.c.Do("SET", rs.sid, string(b))
-		rs.c.Do("EXPIRE", rs.sid, rs.maxlifetime)
+	b, err := encodeGob(rs.values)
+	if err != nil {
+		return
 	}
+	rs.c.Do("SET", rs.sid, string(b))
+	rs.c.Do("EXPIRE", rs.sid, rs.maxlifetime)
 }
 
 type RedisProvider struct {

@@ -52,6 +52,7 @@ type managerConfig struct {
 	CookieName        string `json:"cookieName"`
 	EnableSetCookie   bool   `json:"enableSetCookie,omitempty"`
 	Gclifetime        int64  `json:"gclifetime"`
+	Maxlifetime       int64  `json:"maxLifetime"`
 	Maxage            int    `json:"maxage"`
 	Secure            bool   `json:"secure"`
 	SessionIDHashFunc string `json:"sessionIDHashFunc"`
@@ -81,7 +82,11 @@ func NewManager(provideName, config string) (*Manager, error) {
 	if err != nil {
 		return nil, err
 	}
-	provider.SessionInit(cf.Gclifetime, cf.ProviderConfig)
+	if cf.Maxlifetime == 0 {
+		cf.Maxlifetime = cf.Gclifetime
+	}
+
+	provider.SessionInit(cf.Maxlifetime, cf.ProviderConfig)
 
 	if cf.SessionIDHashFunc == "" {
 		cf.SessionIDHashFunc = "sha1"