在tc上安裝buildkit.tcz，vscode.tcz，打通vscodeonline與openfaas模擬cloudbase打造碎片化程式設計開發部署環境
阿新 • • 發佈：2020-12-21
在文章 我們說到session 是無阻塞的，session的介面對使用者來說是一個字典（C# diction， Go是map）， 儲存所有的ssion也是一個字典（類似於C# Dictionary<string【sessionid 用於區分使用者】,Dictionary<string【使用者設定的key】,object>> ）
首先我們來看看redis session （ledis_session.go）的原始碼吧，和C#相同， 有一個SessionStore負責儲存和Provider；
package redis
import (
"net/http"
"strconv"
"strings"
"sync"
"time"
"github.com/astaxie/beego/session"
"github.com/gomodule/redigo/redis"
)
var redispder = &Provider{}
// MaxPoolSize redis max pool size
var MaxPoolSize = 100
// SessionStore redis session store
type SessionStore struct {
p *redis.Pool
sid string
lock sync.RWMutex
values map[interface{}]interface{}
maxlifetime int64
}
// Set value in redis session
func (rs *SessionStore) Set(key, value interface{}) error {
rs.lock.Lock()
defer rs.lock.Unlock()
rs.values[key] = value
return nil
}
// Get value in redis session
func (rs *SessionStore) Get(key interface{}) interface{} {
rs.lock.RLock()
defer rs.lock.RUnlock()
if v, ok := rs.values[key]; ok {
return v
}
return nil
}
// Delete value in redis session
func (rs *SessionStore) Delete(key interface{}) error {
rs.lock.Lock()
defer rs.lock.Unlock()
delete(rs.values, key)
return nil
}
// Flush clear all values in redis session
func (rs *SessionStore) Flush() error {
rs.lock.Lock()
defer rs.lock.Unlock()
rs.values = make(map[interface{}]interface{})
return nil
}
// SessionID get redis session id
func (rs *SessionStore) SessionID() string {
return rs.sid
}
// SessionRelease save session values to redis
func (rs *SessionStore) SessionRelease(w http.ResponseWriter) {
b, err := session.EncodeGob(rs.values)
if err != nil {
return
}
c := rs.p.Get()
defer c.Close()
c.Do("SETEX", rs.sid, rs.maxlifetime, string(b))
}
// Provider redis session provider
type Provider struct {
maxlifetime int64
savePath string
poolsize int
password string
dbNum int
poollist *redis.Pool
}
// SessionInit init redis session
// savepath like redis server addr,pool size,password,dbnum,IdleTimeout second
// e.g. 127.0.0.1:6379,100,astaxie,0,30
func (rp *Provider) SessionInit(maxlifetime int64, savePath string) error {
rp.maxlifetime = maxlifetime
configs := strings.Split(savePath, ",")
if len(configs) > 0 {
rp.savePath = configs[0]
}
if len(configs) > 1 {
poolsize, err := strconv.Atoi(configs[1])
if err != nil || poolsize < 0 {
rp.poolsize = MaxPoolSize
} else {
rp.poolsize = poolsize
}
} else {
rp.poolsize = MaxPoolSize
}
if len(configs) > 2 {
rp.password = configs[2]
}
if len(configs) > 3 {
dbnum, err := strconv.Atoi(configs[3])
if err != nil || dbnum < 0 {
rp.dbNum = 0
} else {
rp.dbNum = dbnum
}
} else {
rp.dbNum = 0
}
var idleTimeout time.Duration = 0
if len(configs) > 4 {
timeout, err := strconv.Atoi(configs[4])
if err == nil && timeout > 0 {
idleTimeout = time.Duration(timeout) * time.Second
}
}
rp.poollist = &redis.Pool{
Dial: func() (redis.Conn, error) {
c, err := redis.Dial("tcp", rp.savePath)
if err != nil {
return nil, err
}
if rp.password != "" {
if _, err = c.Do("AUTH", rp.password); err != nil {
c.Close()
return nil, err
}
}
// some redis proxy such as twemproxy is not support select command
if rp.dbNum > 0 {
_, err = c.Do("SELECT", rp.dbNum)
if err != nil {
c.Close()
return nil, err
}
}
return c, err
},
MaxIdle: rp.poolsize,
}
rp.poollist.IdleTimeout = idleTimeout
return rp.poollist.Get().Err()
}
// SessionRead read redis session by sid
func (rp *Provider) SessionRead(sid string) (session.Store, error) {
c := rp.poollist.Get()
defer c.Close()
var kv map[interface{}]interface{}
kvs, err := redis.String(c.Do("GET", sid))
if err != nil && err != redis.ErrNil {
return nil, err
}
if len(kvs) == 0 {
kv = make(map[interface{}]interface{})
} else {
if kv, err = session.DecodeGob([]byte(kvs)); err != nil {
return nil, err
}
}
rs := &SessionStore{p: rp.poollist, sid: sid, values: kv, maxlifetime: rp.maxlifetime}
return rs, nil
}
// SessionExist check redis session exist by sid
func (rp *Provider) SessionExist(sid string) bool {
c := rp.poollist.Get()
defer c.Close()
if existed, err := redis.Int(c.Do("EXISTS", sid)); err != nil || existed == 0 {
return false
}
return true
}
// SessionRegenerate generate new sid for redis session
func (rp *Provider) SessionRegenerate(oldsid, sid string) (session.Store, error) {
c := rp.poollist.Get()
defer c.Close()
if existed, _ := redis.Int(c.Do("EXISTS", oldsid)); existed == 0 {
// oldsid doesn't exists, set the new sid directly
// ignore error here, since if it return error
// the existed value will be 0
c.Do("SET", sid, "", "EX", rp.maxlifetime)
} else {
c.Do("RENAME", oldsid, sid)
c.Do("EXPIRE", sid, rp.maxlifetime)
}
return rp.SessionRead(sid)
}
// SessionDestroy delete redis session by id
func (rp *Provider) SessionDestroy(sid string) error {
c := rp.poollist.Get()
defer c.Close()
c.Do("DEL", sid)
return nil
}
// SessionGC Impelment method, no used.
func (rp *Provider) SessionGC() {
}
// SessionAll return all activeSession
func (rp *Provider) SessionAll() int {
return 0
}
func init() {
session.Register("redis", redispder)
}SessionStore的Get，Set，Delete，Flush 都是操作自己的字典values （map[interface{}]interface{}），所以在一個具體的api 裡面設定了session 然後獲取 肯定不會串，因為這個時候都還在記憶體 沒有儲存到redis。Provider的SessionInit實際是初始化redis的一些連結資訊，func (rp *Provider) SessionRead(sid string) (session.Store, error) 這個才是真正載入session的，func (rs *SessionStore) SessionRelease(w http.ResponseWriter) 才是真生儲存session的。具體在哪裡載入和儲存的了？在router.go的func (p *ControllerRegister) ServeHTTP(rw http.ResponseWriter, r *http.Request) 方法裡面有如下程式碼：
// session init
if BConfig.WebConfig.Session.SessionOn {
var err error
context.Input.CruSession, err = GlobalSessions.SessionStart(rw, r)
if err != nil {
logs.Error(err)
exception("503", context)
goto Admin
}
defer func() {
if context.Input.CruSession != nil {
context.Input.CruSession.SessionRelease(rw)
}
}()
}GlobalSessions.SessionStart(rw, r)的實現在session.go的func (manager *Manager) SessionStart(w http.ResponseWriter, r *http.Request) (session Store, err error)方法裡面， 有如下程式碼：
if sid != "" && manager.provider.SessionExist(sid) {
return manager.provider.SessionRead(sid)
}
// Generate a new session
sid, errs = manager.sessionID()
if errs != nil {
return nil, errs
}
session, err = manager.provider.SessionRead(sid)
if err != nil {
return nil, err
}
我們知道在http 請求開始， beego去裝載session，然後在請求方法結束的時候去儲存session。下次獲取的session 就是最近一次儲存的值，而不是最後一次請求的資料。
go的程式碼：
func (c *MainController) V1() {
v := c.GetSession("asta")
time.Sleep(time.Second * 4)
c.SetSession("asta", "v1")
c.Data["json"] = fmt.Sprintf("get session:%s, set session:V1", v)
c.ServeJSON()
}
func (c *MainController) V2() {
v := c.GetSession("asta")
time.Sleep(time.Second * 2)
c.SetSession("asta", "v2")
c.Data["json"] = fmt.Sprintf("get session:%s, set session:V2", v)
c.ServeJSON()
}
func (c *MainController) V3() {
v := c.GetSession("asta")
c.Data["json"] = fmt.Sprintf("get session:%s", v)
c.ServeJSON()
}
html程式碼：
<body>
<div>test</div>
<script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
<input type="button" value="set session" id="setsession"/><br/>
V1: <p id="txt1"></p><br/>
V2: <p id="txt2"></p><br/>
<input type="button" value="get session" id="getsession"/><br/>
V3: <p id="txt3"></p><br/>
<script>
$("#setsession").click(function(){
$.get("http://localhost:8080/v1",function(data){$("#txt1").html(data) ;});
$.get("http://localhost:8080/v2",function(data){$("#txt2").html(data) ;});
});
$("#getsession").click(function(){
$.get("http://localhost:8080/v3",function(data){$("#txt3").html(data) ;});
});
</script>
</body>
先點選setsession呼叫V1和V2， 按理說V1先到達->V2到達->V2返回->V1返回，session最後儲存的是V1的值
【通過列印資訊可以得到如圖】
