Golang的session管理器

对于一些需要对用户进行管理（比如验证操作的权限等）的站点来说,session管理器是必不可少的。下面实现了一个线程安全的简单session管理类。
生产环境：golang1.4.2+win7x64
golang1.4.2+centos6.5×64

1.代码如下：

 

package Helper import ( "crypto/rand"
    "encoding/base64"
    "io"
    "net/http"
    "net/url"
    "strconv"
    "sync"
    "time" ) /*Session会话管理*/ type SessionMgr struct { mCookieName string       //客户端cookie名称
    mLock        sync.RWMutex //互斥(保证线程安全)
    mMaxLifeTime int64        //垃圾回收时间
 mSessions map[string]*Session //保存session的指针[sessionID] = session
} //创建会话管理器(cookieName:在浏览器中cookie的名字;maxLifeTime:最长生命周期)
func NewSessionMgr(cookieName string, maxLifeTime int64) *SessionMgr { mgr := &SessionMgr{mCookieName: cookieName, mMaxLifeTime: maxLifeTime, mSessions: make(map[string]*Session)} //启动定时回收
 go mgr.GC() return mgr } //在开始页面登陆页面，开始Session
func (mgr *SessionMgr) StartSession(w http.ResponseWriter, r *http.Request) string { mgr.mLock.Lock() defer mgr.mLock.Unlock() //无论原来有没有，都重新创建一个新的session
    newSessionID := url.QueryEscape(mgr.NewSessionID()) //存指针
    var session *Session = &Session{mSessionID: newSessionID, mLastTimeAccessed: time.Now(), mValues: make(map[interface{}]interface{})} mgr.mSessions[newSessionID] = session //让浏览器cookie设置过期时间
    cookie := http.Cookie{Name: mgr.mCookieName, Value: newSessionID, Path: "/", HttpOnly: true, MaxAge: int(mgr.mMaxLifeTime)} http.SetCookie(w, &cookie) return newSessionID } //结束Session
func (mgr *SessionMgr) EndSession(w http.ResponseWriter, r *http.Request) { cookie, err := r.Cookie(mgr.mCookieName) if err != nil || cookie.Value == "" { return } else { mgr.mLock.Lock() defer mgr.mLock.Unlock() delete(mgr.mSessions, cookie.Value) //让浏览器cookie立刻过期
        expiration := time.Now() cookie := http.Cookie{Name: mgr.mCookieName, Path: "/", HttpOnly: true, Expires: expiration, MaxAge: -1} http.SetCookie(w, &cookie) } } //结束session
func (mgr *SessionMgr) EndSessionBy(sessionID string) { mgr.mLock.Lock() defer mgr.mLock.Unlock() delete(mgr.mSessions, sessionID) } //设置session里面的值
func (mgr *SessionMgr) SetSessionVal(sessionID string, key interface{}, value interface{}) { mgr.mLock.Lock() defer mgr.mLock.Unlock() if session, ok := mgr.mSessions[sessionID]; ok { session.mValues[key] = value } } //得到session里面的值
func (mgr *SessionMgr) GetSessionVal(sessionID string, key interface{}) (interface{}, bool) { mgr.mLock.RLock() defer mgr.mLock.RUnlock() if session, ok := mgr.mSessions[sessionID]; ok { if val, ok := session.mValues[key]; ok { return val, ok } } return nil, false } //得到sessionID列表
func (mgr *SessionMgr) GetSessionIDList() []string { mgr.mLock.RLock() defer mgr.mLock.RUnlock() sessionIDList := make([]string, 0) for k, _ := range mgr.mSessions { sessionIDList = append(sessionIDList, k) } return sessionIDList[0:len(sessionIDList)] } //判断Cookie的合法性（每进入一个页面都需要判断合法性）
func (mgr *SessionMgr) CheckCookieValid(w http.ResponseWriter, r *http.Request) string { var cookie, err = r.Cookie(mgr.mCookieName) if cookie == nil || err != nil { return "" } mgr.mLock.Lock() defer mgr.mLock.Unlock() sessionID := cookie.Value if session, ok := mgr.mSessions[sessionID]; ok { session.mLastTimeAccessed = time.Now() //判断合法性的同时，更新最后的访问时间
        return sessionID } return "" } //更新最后访问时间
func (mgr *SessionMgr) GetLastAccessTime(sessionID string) time.Time { mgr.mLock.RLock() defer mgr.mLock.RUnlock() if session, ok := mgr.mSessions[sessionID]; ok { return session.mLastTimeAccessed } return time.Now() } //GC回收
func (mgr *SessionMgr) GC() { mgr.mLock.Lock() defer mgr.mLock.Unlock() for sessionID, session := range mgr.mSessions { //删除超过时限的session
        if session.mLastTimeAccessed.Unix()+mgr.mMaxLifeTime < time.Now().Unix() { delete(mgr.mSessions, sessionID) } } //定时回收
    time.AfterFunc(time.Duration(mgr.mMaxLifeTime)*time.Second, func() { mgr.GC() }) } //创建唯一ID
func (mgr *SessionMgr) NewSessionID() string { b := make([]byte, 32) if _, err := io.ReadFull(rand.Reader, b); err != nil { nano := time.Now().UnixNano() //微秒
        return strconv.FormatInt(nano, 10) } return base64.URLEncoding.EncodeToString(b) } //—————————————————————————— /*会话*/ type Session struct { mSessionID string                      //唯一id
    mLastTimeAccessed time.Time                   //最后访问时间
    mValues           map[interface{}]interface{} //其它对应值(保存用户所对应的一些值，比如用户权限之类)
}

 

 

 

2.使用方法
①定义一个全局变量

var sessionMgr *Helper.SessionMgr = nil //session管理器

 

②在程序入口处，创建一个session的对象

//创建session管理器,”TestCookieName”是浏览器中cookie的名字，3600是浏览器cookie的有效时间（秒） 
sessionMgr = Helper.NewSessionMgr("TestCookieName", 3600)

 

③在用户登录时进行登录用户合法性判断并设置属性

//处理登录 
func login(w http.ResponseWriter, r *http.Request) {  3     if r.Method == "GET" {  4         t, _ := template.ParseFiles("web/MgrSvr_login.html")  5  t.Execute(w, nil)  6   
    } else if r.Method == "POST" {  8         //请求的是登陆数据，那么执行登陆的逻辑判断 
 r.ParseForm() 10   
        //可以使用template.HTMLEscapeString()来避免用户进行js注入 
        username := r.FormValue("username") 13         password := r.FormValue("password") 14   
        //在数据库中得到对应数据 
        var userID int = 0  
  
        userRow := db.QueryRow(loginUserQuery, username, password) 19         userRow.Scan(&userID) 20   
        //TODO:判断用户名和密码 
        if userID != 0 { 23             //创建客户端对应cookie以及在服务器中进行记录 
            var sessionID = sessionMgr.StartSession(w, r) 25   
            var loginUserInfo = UserInfo{ID: userID, UserName: username, Password: password, Alias: alias, 27  Desc: desc, ChannelAuth: channel_authority, IsSuperAdmin: is_super_admin, IsNewClientAuth: is_newclient_authority, 28  IsPayAuth: is_pay_authority, IsItemsAuth: is_itmes_authority, IsRealtimeAuth: is_realtime_authority, 29  IsPayCodeAuth: is_paycode_authority, IsUserAuth: is_user_authority, IsBgOpAuth: is_bgop_authority, IsHZRaidenNMMWeak: is_hz_raidenn_mmweak, 30  IsManualDataMgr: is_manual_data_mgr, IsManualDataQuery: is_manual_data_query} 31   
            //踢除重复登录的 
            var onlineSessionIDList = sessionMgr.GetSessionIDList() 34   
            for _, onlineSessionID := range onlineSessionIDList { 36                 if userInfo, ok := sessionMgr.GetSessionVal(onlineSessionID, "UserInfo"); ok { 37                     if value, ok := userInfo.(UserInfo); ok { 38                         if value.ID == userID { 39  sessionMgr.EndSessionBy(onlineSessionID) 40  } 41  } 42  } 43  } 44   
            //设置变量值 
 sessionMgr.SetSessionVal(sessionID, "UserInfo", loginUserInfo) 47   
            //TODO 设置其它数据 49   
            //TODO 转向成功页面 
  
            return  
 } 54  } 55 }

 

③在用户退出时删除对应session

//处理退出 
func logout(w http.ResponseWriter, r *http.Request) { 3     sessionMgr.EndSession(w, r) //用户退出时删除对应session 
    http.Redirect(w, r, "/login", http.StatusFound) 5     return  
}

 

④在每个页面中进行用户合法性验证

func test_session_valid(w http.ResponseWriter, r *http.Request) { 2     var sessionID = sessionMgr.CheckCookieValid(w, r) 3   
    if sessionID == "" { 5         http.Redirect(w, r, "/login", http.StatusFound) 6         return  
 } 8 }