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入口
api := iris.New()
api.Adapt(gm.NewSession())
session的构造
func NewSession() sessions.Sessions {
db := redis.New(rs.Config{Network: rs.DefaultRedisNetwork,
Addr: config.Instance().Redis.Address,
Password: config.Instance().Redis.Password,
Database: "",
MaxIdle: 0,
MaxActive: 0,
IdleTimeout: rs.DefaultRedisIdleTimeout,
Prefix: "",
MaxAgeSeconds: config.Instance().Redis.MaxAgeSeconds}) // optionally configure the bridge between your redis server
mySessions := sessions.New(sessions.Config{Cookie: configs.GetSessionConfig().Cookie, Expires: configs.GetSessionConfig().Expires})
mySessions.UseDatabase(db)
return mySessions
}MaxAgeSeconds //指的是session在数据库存的有效期
Expires //指的是session的有效期
回到刚才的api.Adapt(gm.NewSession())，装饰器
func (s *sessions) Adapt(frame *iris.Policies) {
// for newcomers this maybe looks strange:
// Each policy is an adaptor too, so they all can contain an Adapt.
// If they contains an Adapt func then the policy is an adaptor too and this Adapt func is called
// by Iris on .Adapt(...)
policy := iris.SessionsPolicy{
Start: s.Start,
Destroy: s.Destroy,
}
policy.Adapt(frame)func (s SessionsPolicy) Adapt(frame *Policies) {
if s.Start != nil {
frame.SessionsPolicy.Start = s.Start
}
if s.Destroy != nil {
frame.SessionsPolicy.Destroy = s.Destroy
}
}使用
调用context.Session()，获取到session对象
func (ctx *Context) Session() Session {
policy := ctx.framework.policies.SessionsPolicy
if policy.Start == nil {
ctx.framework.Log(DevMode,
errSessionsPolicyIsMissing.Format(ctx.RemoteAddr(), ctx.framework.Config.VHost).Error())
return nil
}
if ctx.session == nil {
ctx.session = policy.Start(ctx.ResponseWriter, ctx.Request)
}
return ctx.session
}如果session==nil，就会调用start
func (s *sessions) Start(res http.ResponseWriter, req *http.Request) iris.Session {
var sess iris.Session
cookieValue := GetCookie(s.config.Cookie, req)
if cookieValue == "" { // cookie doesn't exists, let's generate a session and add set a cookie
sid := SessionIDGenerator(s.config.CookieLength)
sess = s.provider.Init(sid, s.config.Expires)
cookie := &http.Cookie{}
// The RFC makes no mention of encoding url value, so here I think to encode both sessionid key and the value using the safe(to put and to use as cookie) url-encoding
cookie.Name = s.config.Cookie
cookie.Value = sid
cookie.Path = "/"
if !s.config.DisableSubdomainPersistence {
requestDomain := req.URL.Host
if portIdx := strings.IndexByte(requestDomain, ':'); portIdx > 0 {
requestDomain = requestDomain[0:portIdx]
}
if IsValidCookieDomain(requestDomain) {
// RFC2109, we allow level 1 subdomains, but no further
// if we have localhost.com , we want the localhost.cos.
// so if we have something like: mysubdomain.localhost.com we want the localhost here
// if we have mysubsubdomain.mysubdomain.localhost.com we want the .mysubdomain.localhost.com here
// slow things here, especially the 'replace' but this is a good and understable( I hope) way to get the be able to set cookies from subdomains & domain with 1-level limit
if dotIdx := strings.LastIndexByte(requestDomain, '.'); dotIdx > 0 {
// is mysubdomain.localhost.com || mysubsubdomain.mysubdomain.localhost.com
s := requestDomain[0:dotIdx] // set mysubdomain.localhost || mysubsubdomain.mysubdomain.localhost
if secondDotIdx := strings.LastIndexByte(s, '.'); secondDotIdx > 0 {
//is mysubdomain.localhost || mysubsubdomain.mysubdomain.localhost
s = s[secondDotIdx+1:] // set to localhost || mysubdomain.localhost
}
// replace the s with the requestDomain before the domain's siffux
subdomainSuff := strings.LastIndexByte(requestDomain, '.')
if subdomainSuff > len(s) { // if it is actual exists as subdomain suffix
requestDomain = strings.Replace(requestDomain, requestDomain[0:subdomainSuff], s, 1) // set to localhost.com || mysubdomain.localhost.com
}
}
// finally set the .localhost.com (for(1-level) || .mysubdomain.localhost.com (for 2-level subdomain allow)
cookie.Domain = "." + requestDomain // . to allow persistence
}
}
cookie.HttpOnly = true
// MaxAge=0 means no 'Max-Age' attribute specified.
// MaxAge<0 means delete cookie now, equivalently 'Max-Age: 0'
// MaxAge>0 means Max-Age attribute present and given in seconds
if s.config.Expires >= 0 {
if s.config.Expires == 0 { // unlimited life
cookie.Expires = CookieExpireUnlimited
} else { // > 0
cookie.Expires = time.Now().Add(s.config.Expires)
}
cookie.MaxAge = int(cookie.Expires.Sub(time.Now()).Seconds())
}
// encode the session id cookie client value right before send it.
cookie.Value = s.encodeCookieValue(cookie.Value)
AddCookie(cookie, res)
} else {
cookieValue = s.decodeCookieValue(cookieValue)
sess = s.provider.Read(cookieValue, s.config.Expires)
}
return sess
}再设置cookie.Domain的时候，req.URL作为服务端的时候，是没有Host信息的，所以cookie.Domain 会默认空串。
再看s.provider.Init
// Init creates the session and returns it
func (p *provider) Init(sid string, expires time.Duration) iris.Session {
newSession := p.newSession(sid, expires)
p.mu.Lock()
p.sessions[sid] = newSession
p.mu.Unlock()
return newSession
}init的时候做了两件事：
1.newSession
2.将session存到p.sessions里面
// newSession returns a new session from sessionid
func (p *provider) newSession(sid string, expires time.Duration) *session {
sess := &session{
sid: sid,
provider: p,
values: p.loadSessionValues(sid),
flashes: make(map[string]*flashMessage),
}
if expires > 0 { // if not unlimited life duration and no -1 (cookie remove action is based on browser's session)
time.AfterFunc(expires, func() {
// the destroy makes the check if this session is exists then or not,
// this is used to destroy the session from the server-side also
// it's good to have here for security reasons, I didn't add it on the gc function to separate its action
p.Destroy(sid)
})
}
return sess
}这里可以看到在配置文件中设置的expire 是用来起了一个定时任务，之后删掉这个session
func (p *provider) Destroy(sid string) {
p.mu.Lock()
if sess, found := p.sessions[sid]; found {
sess.values = nil
sess.flashes = nil
delete(p.sessions, sid)
p.updateDatabases(sid, nil)
}
p.mu.Unlock()
}destory的时候：
如果没有删除：
1.从p.sessions里面删除
2.更新到数据库