wide/session/sessions.go

403 lines
10 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.
// Package session includes session related 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 (
"bytes"
"encoding/json"
"net/http"
"os"
"sort"
"strconv"
"sync"
"time"
"github.com/b3log/wide/conf"
"github.com/b3log/wide/event"
"github.com/b3log/wide/log"
"github.com/b3log/wide/util"
"github.com/gorilla/sessions"
"github.com/gorilla/websocket"
)
const (
sessionStateActive = iota
sessionStateClosed // (not used so far)
)
// Logger.
var logger = log.NewLogger(os.Stdout)
var (
// SessionWS holds all session channels. <sid, *util.WSChannel>
SessionWS = map[string]*util.WSChannel{}
// EditorWS holds all editor channels. <sid, *util.WSChannel>
EditorWS = map[string]*util.WSChannel{}
// OutputWS holds all output channels. <sid, *util.WSChannel>
OutputWS = map[string]*util.WSChannel{}
// NotificationWS holds all notification channels. <sid, *util.WSChannel>
NotificationWS = map[string]*util.WSChannel{}
)
// HTTP session store.
var HTTPSession = sessions.NewCookieStore([]byte("BEYOND"))
// WideSession represents a 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 wSessions []*WideSession
// Wide sessions.
var WideSessions wSessions
// Exclusive lock.
var mutex sync.Mutex
// FixedTimeRelease releases invalid sessions.
//
// 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) {
logger.Debugf("Removes a invalid session [%s], user [%s]", s.ID, s.Username)
WideSessions.Remove(s.ID)
}
}
}
}()
}
// Online user statistic report.
type userReport struct {
username string
sessionCnt int
processCnt int
updated time.Time
}
// report returns a online user statistics in pretty format.
func (u *userReport) report() string {
return "[" + u.username + "] has [" + strconv.Itoa(u.sessionCnt) + "] sessions and [" + strconv.Itoa(u.processCnt) +
"] running processes, latest activity [" + u.updated.Format("2006-01-02 15:04:05") + "]"
}
// FixedTimeReport reports the Wide sessions status periodically (10 minutes).
func FixedTimeReport() {
go func() {
for _ = range time.Tick(10 * time.Minute) {
users := userReports{}
processSum := 0
for _, s := range WideSessions {
processCnt := len(s.Processes)
processSum += processCnt
if report, exists := contains(users, s.Username); exists {
if s.Updated.After(report.updated) {
report.updated = s.Updated
}
report.sessionCnt++
report.processCnt += processCnt
} else {
users = append(users, &userReport{username: s.Username, sessionCnt: 1, processCnt: processCnt, updated: s.Updated})
}
}
var buf bytes.Buffer
buf.WriteString("\n [" + strconv.Itoa(len(users)) + "] users, [" + strconv.Itoa(processSum) + "] running processes and [" +
strconv.Itoa(len(WideSessions)) + "] sessions currently\n")
sort.Sort(users)
for _, t := range users {
buf.WriteString(" " + t.report() + "\n")
}
logger.Info(buf.String())
}
}()
}
func contains(reports []*userReport, username string) (*userReport, bool) {
for _, ur := range reports {
if username == ur.username {
return ur, true
}
}
return nil, false
}
type userReports []*userReport
func (f userReports) Len() int { return len(f) }
func (f userReports) Swap(i, j int) { f[i], f[j] = f[j], f[i] }
func (f userReports) Less(i, j int) bool { return f[i].processCnt > f[j].processCnt }
// 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)
wSession = WideSessions.New(httpSession, sid)
logger.Tracef("Created a wide session [%s] for websocket reconnecting, user [%s]", sid, wSession.Username)
}
conn, _ := websocket.Upgrade(w, r, nil, 1024, 1024)
wsChan := util.WSChannel{Sid: sid, Conn: conn, Request: r, Time: time.Now()}
ret := map[string]interface{}{"output": "Session initialized", "cmd": "init-session"}
err := wsChan.WriteJSON(&ret)
if nil != err {
return
}
SessionWS[sid] = &wsChan
logger.Tracef("Open a new [Session Channel] with session [%s], %d", sid, len(SessionWS))
input := map[string]interface{}{}
for {
if err := wsChan.ReadJSON(&input); err != nil {
logger.Tracef("[Session Channel] of session [%s] disconnected, releases all resources with it, user [%s]", sid, wSession.Username)
WideSessions.Remove(sid)
return
}
ret = map[string]interface{}{"output": "", "cmd": "session-output"}
if err := wsChan.WriteJSON(&ret); err != nil {
logger.Error("Session WS ERROR: " + err.Error())
return
}
wsChan.Time = time.Now()
}
}
// SaveContent handles request of session content string.
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 {
logger.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.Users {
if user.Name == wSession.Username {
// update the variable in-memory, session.FixedTimeSave() function will persist it periodically
user.LatestSessionContent = wSession.Content
user.Lived = time.Now().UnixNano()
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 *wSessions) 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 *wSessions) 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 *wSessions) 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 {
logger.Errorf("Can't kill process [%d] of session [%s], user [%s]", p.Pid, sid, s.Username)
} else {
logger.Debugf("Killed a process [%d] of session [%s], user [%s]", p.Pid, sid, s.Username)
}
}
// 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)
}
cnt := 0 // count wide sessions associated with HTTP session
for _, ses := range *sessions {
if ses.HTTPSession.Values["id"] == s.HTTPSession.Values["id"] {
cnt++
}
}
logger.Debugf("Removed a session [%s] of user [%s], it has [%d] sessions currently", sid, s.Username, cnt)
return
}
}
}
// GetByUsername gets wide sessions.
func (sessions *wSessions) 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
}