wide/session/sessions.go

323 lines
8.0 KiB
Go

// Copyright (c) 2014, B3log
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Session manipulations.
//
// Wide server side needs maintain two kinds of sessions:
//
// 1. HTTP session: mainly used for login authentication
// 2. Wide session: browser tab open/refresh will create one, and associates with HTTP session
//
// When a session gone: release all resources associated with it, such as running processes, event queues.
package session
import (
"encoding/json"
"net/http"
"os"
"sync"
"time"
"github.com/b3log/wide/conf"
"github.com/b3log/wide/event"
"github.com/b3log/wide/util"
"github.com/golang/glog"
"github.com/gorilla/sessions"
"github.com/gorilla/websocket"
)
const (
SessionStateActive = iota // session state: active
SessionStateClosed // session state: closed (not used so far)
)
var (
// Session channels. <sid, *util.WSChannel>
SessionWS = map[string]*util.WSChannel{}
// Editor channels. <sid, *util.WSChannel>
EditorWS = map[string]*util.WSChannel{}
// Output channels. <sid, *util.WSChannel>
OutputWS = map[string]*util.WSChannel{}
// Notification channels. <sid, *util.WSChannel>
NotificationWS = map[string]*util.WSChannel{}
)
// HTTP session store.
var HTTPSession = sessions.NewCookieStore([]byte("BEYOND"))
// Wide session, associated with a browser tab.
type WideSession struct {
Id string // id
Username string // username
HTTPSession *sessions.Session // HTTP session related
Processes []*os.Process // process set
EventQueue *event.UserEventQueue // event queue
State int // state
Content *conf.LatestSessionContent // the latest session content
Created time.Time // create time
Updated time.Time // the latest use time
}
// Type of wide sessions.
type Sessions []*WideSession
// Wide sessions.
var WideSessions Sessions
// Exclusive lock.
var mutex sync.Mutex
// In some special cases (such as a browser uninterrupted refresh / refresh in the source code view) will occur
// some invalid sessions, the function checks and removes these invalid sessions periodically (1 hour).
//
// Invalid sessions: sessions that not used within 30 minutes, refers to WideSession.Updated field.
func FixedTimeRelease() {
go func() {
for _ = range time.Tick(time.Hour) {
hour, _ := time.ParseDuration("-30m")
threshold := time.Now().Add(hour)
for _, s := range WideSessions {
if s.Updated.Before(threshold) {
glog.V(3).Infof("Removes a invalid session [%s]", s.Id)
WideSessions.Remove(s.Id)
}
}
}
}()
}
// WSHandler handles request of creating session channel.
//
// When a channel closed, releases all resources associated with it.
func WSHandler(w http.ResponseWriter, r *http.Request) {
sid := r.URL.Query()["sid"][0]
wSession := WideSessions.Get(sid)
if nil == wSession {
httpSession, _ := HTTPSession.Get(r, "wide-session")
if httpSession.IsNew {
return
}
httpSession.Options.MaxAge = conf.Wide.HTTPSessionMaxAge
httpSession.Save(r, w)
WideSessions.New(httpSession, sid)
glog.Infof("Created a wide session [%s] for websocket reconnecting", sid)
}
conn, _ := websocket.Upgrade(w, r, nil, 1024, 1024)
wsChan := util.WSChannel{Sid: sid, Conn: conn, Request: r, Time: time.Now()}
SessionWS[sid] = &wsChan
ret := map[string]interface{}{"output": "Session initialized", "cmd": "init-session"}
wsChan.Conn.WriteJSON(&ret)
glog.V(4).Infof("Open a new [Session Channel] with session [%s], %d", sid, len(SessionWS))
input := map[string]interface{}{}
for {
if err := wsChan.Conn.ReadJSON(&input); err != nil {
glog.V(3).Infof("[Session Channel] of session [%s] disconnected, releases all resources with it", sid)
WideSessions.Remove(sid)
return
}
ret = map[string]interface{}{"output": "", "cmd": "session-output"}
if err := wsChan.Conn.WriteJSON(&ret); err != nil {
glog.Error("Session WS ERROR: " + err.Error())
return
}
wsChan.Time = time.Now()
}
}
// SaveContent handles request of session content storing.
func SaveContent(w http.ResponseWriter, r *http.Request) {
data := map[string]interface{}{"succ": true}
defer util.RetJSON(w, r, data)
args := struct {
Sid string
*conf.LatestSessionContent
}{}
if err := json.NewDecoder(r.Body).Decode(&args); err != nil {
glog.Error(err)
data["succ"] = false
return
}
wSession := WideSessions.Get(args.Sid)
if nil == wSession {
data["succ"] = false
return
}
wSession.Content = args.LatestSessionContent
for _, user := range conf.Wide.Users {
if user.Name == wSession.Username {
// update the variable in-memory, conf.FixedTimeSave() function will persist it periodically
user.LatestSessionContent = wSession.Content
wSession.Refresh()
return
}
}
}
// SetProcesses binds process set with the wide session.
func (s *WideSession) SetProcesses(ps []*os.Process) {
s.Processes = ps
s.Refresh()
}
// Refresh refreshes the channel by updating its use time.
func (s *WideSession) Refresh() {
s.Updated = time.Now()
}
// New creates a wide session.
func (sessions *Sessions) New(httpSession *sessions.Session, sid string) *WideSession {
mutex.Lock()
defer mutex.Unlock()
now := time.Now()
// create user event queuselect
userEventQueue := event.UserEventQueues.New(sid)
ret := &WideSession{
Id: sid,
Username: httpSession.Values["username"].(string),
HTTPSession: httpSession,
EventQueue: userEventQueue,
State: SessionStateActive,
Content: &conf.LatestSessionContent{},
Created: now,
Updated: now,
}
*sessions = append(*sessions, ret)
return ret
}
// Get gets a wide session with the specified session id.
func (sessions *Sessions) Get(sid string) *WideSession {
mutex.Lock()
defer mutex.Unlock()
for _, s := range *sessions {
if s.Id == sid {
return s
}
}
return nil
}
// Remove removes a wide session specified with the given session id, releases resources associated with it.
//
// Session-related resources:
//
// 1. user event queue
// 2. process set
// 3. websocket channels
func (sessions *Sessions) Remove(sid string) {
mutex.Lock()
defer mutex.Unlock()
for i, s := range *sessions {
if s.Id == sid {
// remove from session set
*sessions = append((*sessions)[:i], (*sessions)[i+1:]...)
// close user event queue
event.UserEventQueues.Close(sid)
// kill processes
for _, p := range s.Processes {
if err := p.Kill(); nil != err {
glog.Errorf("Can't kill process [%d] of session [%s]", p.Pid, sid)
} else {
glog.V(3).Infof("Killed a process [%d] of session [%s]", p.Pid, sid)
}
}
// close websocket channels
if ws, ok := OutputWS[sid]; ok {
ws.Close()
delete(OutputWS, sid)
}
if ws, ok := NotificationWS[sid]; ok {
ws.Close()
delete(NotificationWS, sid)
}
if ws, ok := SessionWS[sid]; ok {
ws.Close()
delete(SessionWS, sid)
}
glog.V(3).Infof("Removed a session [%s]", s.Id)
cnt := 0 // count wide sessions associated with HTTP session
for _, s := range *sessions {
if s.HTTPSession.ID == s.HTTPSession.ID {
cnt++
}
}
glog.V(3).Infof("User [%s] has [%d] sessions", s.Username, cnt)
return
}
}
}
// GetByUsername gets wide sessions.
func (sessions *Sessions) GetByUsername(username string) []*WideSession {
mutex.Lock()
defer mutex.Unlock()
ret := []*WideSession{}
for _, s := range *sessions {
if s.Username == username {
ret = append(ret, s)
}
}
return ret
}