/
sessionstore.go
188 lines (154 loc) · 4.43 KB
/
sessionstore.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
/******************************************************************************
*
* Description:
*
* Session management.
*
*****************************************************************************/
package main
import (
"container/list"
"log"
"net/http"
"sync"
"time"
"github.com/gorilla/websocket"
"github.com/tinode/chat/pbx"
"github.com/tinode/chat/server/store"
"github.com/tinode/chat/server/store/types"
)
// SessionStore holds live sessions. Long polling sessions are stored in a linked list with
// most recent sessions on top. In addition all sessions are stored in a map indexed by session ID.
type SessionStore struct {
lock sync.Mutex
// Support for long polling sessions: a list of sessions sorted by last access time.
// Needed for cleaning abandoned sessions.
lru *list.List
lifeTime time.Duration
// All sessions indexed by session ID
sessCache map[string]*Session
}
// NewSession creates a new session and saves it to the session store.
func (ss *SessionStore) NewSession(conn interface{}, sid string) (*Session, int) {
var s Session
s.sid = sid
switch c := conn.(type) {
case *websocket.Conn:
s.proto = WEBSOCK
s.ws = c
case http.ResponseWriter:
s.proto = LPOLL
// no need to store c for long polling, it changes with every request
case *ClusterNode:
s.proto = CLUSTER
s.clnode = c
case pbx.Node_MessageLoopServer:
s.proto = GRPC
s.grpcnode = c
default:
s.proto = NONE
}
if s.proto != NONE {
s.subs = make(map[string]*Subscription)
s.send = make(chan interface{}, 256) // buffered
s.stop = make(chan interface{}, 1) // Buffered by 1 just to make it non-blocking
s.detach = make(chan string, 64) // buffered
}
s.lastTouched = time.Now()
if s.sid == "" {
s.sid = store.GetUidString()
}
ss.lock.Lock()
ss.sessCache[s.sid] = &s
count := len(ss.sessCache)
var expired []*Session
if s.proto == LPOLL {
// Only LP sessions need to be sorted by last active
s.lpTracker = ss.lru.PushFront(&s)
// Remove expired sessions
expire := s.lastTouched.Add(-ss.lifeTime)
for elem := ss.lru.Back(); elem != nil; elem = ss.lru.Back() {
sess := elem.Value.(*Session)
if sess.lastTouched.Before(expire) {
ss.lru.Remove(elem)
delete(ss.sessCache, sess.sid)
expired = append(expired, sess)
} else {
break // don't need to traverse further
}
}
count -= len(expired)
}
ss.lock.Unlock()
for _, sess := range expired {
// This locks the session. Thus cleaning up outside of the
// sessionStore lock. Otherwise deadlock.
sess.cleanUp(true)
}
statsSet("LiveSessions", int64(len(ss.sessCache)))
statsInc("TotalSessions", 1)
return &s, count
}
// Get fetches a session from store by session ID.
func (ss *SessionStore) Get(sid string) *Session {
ss.lock.Lock()
defer ss.lock.Unlock()
if sess := ss.sessCache[sid]; sess != nil {
if sess.proto == LPOLL {
ss.lru.MoveToFront(sess.lpTracker)
sess.lastTouched = time.Now()
}
return sess
}
return nil
}
// Delete removes session from store.
func (ss *SessionStore) Delete(s *Session) {
ss.lock.Lock()
defer ss.lock.Unlock()
delete(ss.sessCache, s.sid)
if s.proto == LPOLL {
ss.lru.Remove(s.lpTracker)
}
statsSet("LiveSessions", int64(len(ss.sessCache)))
}
// Shutdown terminates sessionStore. No need to clean up.
// Don't send to clustered sessions, their servers are not being shut down.
func (ss *SessionStore) Shutdown() {
ss.lock.Lock()
defer ss.lock.Unlock()
shutdown := NoErrShutdown(types.TimeNow())
for _, s := range ss.sessCache {
if s.stop != nil && s.proto != CLUSTER {
s.stop <- s.serialize(shutdown)
}
}
log.Printf("SessionStore shut down, sessions terminated: %d", len(ss.sessCache))
}
// EvictUser terminates all sessions of a given user.
func (ss *SessionStore) EvictUser(uid types.Uid, skipSid string) {
ss.lock.Lock()
defer ss.lock.Unlock()
evicted := NoErrEvicted("", "", types.TimeNow())
for _, s := range ss.sessCache {
if s.uid == uid && s.stop != nil && s.sid != skipSid {
s.stop <- s.serialize(evicted)
delete(ss.sessCache, s.sid)
if s.proto == LPOLL {
ss.lru.Remove(s.lpTracker)
}
}
}
statsSet("LiveSessions", int64(len(ss.sessCache)))
}
// NewSessionStore initializes a session store.
func NewSessionStore(lifetime time.Duration) *SessionStore {
ss := &SessionStore{
lru: list.New(),
lifeTime: lifetime,
sessCache: make(map[string]*Session),
}
statsRegisterInt("LiveSessions")
statsRegisterInt("TotalSessions")
return ss
}